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CDAWeb Served Heliophysics Datasets Beginning with 'D'

DAWN_HELIO1HR_POSITION: Position in heliocentric coordinates from SPDF Helioweb - Natalia Papitashvili (NASA/GSFC/SPDF)

DE1_1MIN_RIMS: DE-1 Retarding Ion Mass Spectrometer Empirical Model - Dr. Charles R. Chappell (NASA/MSFC)

DE1_2SEC_OA: de1 2 second orbit and additude data - David Winningham (Southwest Research Institute)

DE1_62MS_MAGA-GMS: DE-1 Magnetometer (MAG-A) 62.5 msec GMS Data - Dr. Masahisa Sugiura (NASA/GSFC)

DE1_6SEC_MAGAGMS: DE-1 Magnetometer (MAG-A) 6 second GMS Data - Dr. Masahisa Sugiura (NASA/GSFC)

DE1_PWI_LFC-SPECTRA: DE-1 PWI: LOW Frequency Correlator (LFC) - Donald Gurnett (University Iowa)

DE1_PWI_OR-AT: DE-1 PWI: Ephemeris and Attitude Parameters - Donald Gurnett (University Iowa)

DE1_PWI_SFC-SPECTRA: DE-1 PWI: Step Frequency Correlator (SFC) - Donald Gurnett (University Iowa)

DE2_62MS_VEFIMAGB: 16-msec merged magnetic and electric field data - Jim Slavin (NASA/GSFC)

DE2_AC500MS_VEFI: 500-msec AC data from each channel for each of the 3 spectrometers of the vector electric field instrument - N.C. Maynard/R. Pfaff (NASA/GSFC)

DE2_DCA500MS_VEFI: 500-msec spectrometer vector electric field instrument - Dr. Nelson C. Maynard (NASA/GSFC)

DE2_DUCT16MS_RPA: De-2 duct 16ms rpa - William Hanson (University of Texas, Dallas)

DE2_ION2S_RPA: 2-sec ion temperature, velocity, and densities (O+, H+, He+, molecular) - Rod Heelis (University of Texas, Dallas)

DE2_LAPI_ELECTRON-FLUX-COUNTS-PPS1: DE-2, LAPI_Corrected Electron Counts and Flux from Power Supply 1 IDFS format - Dr. J. David Winningham (Southwest Research Institute)

DE2_LAPI_ELECTRON-FLUX-COUNTS-PPS2: DE-2, LAPI_Corrected Electron Counts and Flux from Power Supply 2 IDFS format - Dr. J. David Winningham (Southwest Research Institute)

DE2_LAPI_GEIGER-MUELLER: DE-2, LAPI_Corrected IDFS format - Dr. J. David Winningham (Southwest Research Institute)

DE2_LAPI_GEIGER-MUELLER-RATIO: DE-2, LAPI_Corrected IDFS format - Dr. J. David Winningham (Southwest Research Institute)

DE2_LAPI_ION-FLUX-COUNTS-PPS1: DE-2, LAPI_Corrected Ion Counts and Flux from Power Supply 1 IDFS format - Dr. J. David Winningham (Southwest Research Institute)

DE2_LAPI_ION-FLUX-COUNTS-PPS2: DE-2, LAPI_Corrected Ion Counts and Flux from Power Supply 2 IDFS format - Dr. J. David Winningham (Southwest Research Institute)

DE2_LAPI_LAPI-MAG: DE-2, LAPI_Corrected IDFS format - David Winningham (Southwest Research Institute)

DE2_LAPI_ORBIT-ATTITUDE: DE-2, OA_Corrected IDFS format - David Winningham (Southwest Research Institute)

DE2_LAPI_ORBIT-ATTITUDE-MAGB: DE-2, OA_Corrected IDFS format - David Winningham (Southwest Research Institute)

DE2_LAPI_PITCH-ANGLES: DE-2, LAPI_Corrected Precopitation and Pitch Angles IDFS format - David Winningham (Southwest Research Institute)

DE2_LAPI_PROJECTED-MAGB: DE-2, MAGB_Corrected IDFS format - David Winningham (Southwest Research Institute)

DE2_LAPI_SC-MAGB: DE-2, MAGB_Corrected IDFS format - David Winningham (Southwest Research Institute)

DE2_LAPI_SHAFT-ENCODER-ANGLE: DE-2, LAPI_Corrected IDFS format - David Winningham (Southwest Research Institute)

DE2_NEUTRAL1S_NACS: 1-sec ambient densities and error rates - Nelson W. Spencer (NASA/GSFC)

DE2_NEUTRAL8S_FPI: 8-sec neutral wind and temperature data from FPI plus WATS - Dr. R. Niciejewski (University of Michigan)

DE2_PLASMA500MS_LANG: .5 sec electron temperature, plasma density, and satellite potential - Larry H. Brace (NASA/GSFC)

DE2_UA16S_ALL: 16-sec combined neutral and plasma unified abstract (UA) data - Mr. Larry H. Brace (NASA/GSFC)

DE2_VION250MS_IDM: 250-msec cross track ion drift velocities - Rod Heelis (University of Texas, Dallas)

DE2_WIND2S_WATS: 2-sec neutral densities, temperature, and horizontal (zonal) wind velocity - Nelson W. Spencer (NASA/GSFC)

DE_UV_SAI: DE-1 Spin-scan Auroral Imager (SAI) Ultraviolet Images - Louis A. Frank (The University of Iowa)

DE_VS_EICS: Dynamics Explorer Energetic Ion Composition Spectrometer (EICS), Validated Summary Data - E. G. Shelley (Lockheed Martin)

DMSP-F06_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F07_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F08_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F09_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F12_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F13_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F14_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F15_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F16_SSIES-3_THERMAL-PLASMA: DMSP thermal plasma data - William Hanson, Rod Heelis, Marc Hairston (University of Texas Dallas, Center for Space Sciences)

DMSP-F16_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F16_SSM_MAGNETOMETER: Defense Meteorolgy Satellite Program F16 Vector Magnetometer Measurements (850km Altitude) - Staff (AFRL, NGDC, CU)

DMSP-F17_SSIES-3_THERMAL-PLASMA: DMSP thermal plasma data - William Hanson, Rod Heelis, Marc Hairston (University of Texas Dallas, Center for Space Sciences)

DMSP-F17_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F17_SSM_MAGNETOMETER: Defense Meteorolgy Satellite Program F17 Vector Magnetometer Measurements (850km Altitude) - Staff (AFRL, NGDC, CU)

DMSP-F18_SSIES-3_THERMAL-PLASMA: DMSP thermal plasma data - William Hanson, Rod Heelis, Marc Hairston (University of Texas Dallas, Center for Space Sciences)

DMSP-F18_SSJ_PRECIPITATING-ELECTRONS-IONS: Precipitating electrons and ions observed at nominally 850km. - Staff (AFRL, NGDC, CU)

DMSP-F18_SSM_MAGNETOMETER: Defense Meteorolgy Satellite Program F18 Vector Magnetometer Measurements (850km Altitude) - Staff (AFRL, NGDC, CU)

DMSPF16_R0_SSUSI: Links to DMSP F16 SSUSI NetCDF data, KZM image files and other sources. - Larry Paxton (JHUAPL)

DMSPF17_R0_SSUSI: Links to DMSP F17 SSUSI NetCDF data, KZM image files and other sources. - Larry Paxton (JHUAPL)

DMSPF18_R0_SSUSI: Links to DMSP F18 SSUSI NetCDF data, KMZ image files and other sources. - Larry Paxton (JHUAPL)

DMSP_R0_SSIES: Link to DMSP thermal plasma analysis package data service at the Center for Space Sciences, University of Texas at Dallas. - Center for Space Sciences (UTD)

DMSP_R0_SSJ4: Link to DMSP low energy electron/ion plots and data at JHU/APL - Hardy (AFGL)

DN_K0_GBAY: DARN Goose Bay, Key Parameters - R. Greenwald (JHU/APL)

DN_K0_HANK: DARN Hankasalmi, Key Parameters - R. Greenwald (JHU/APL)

DN_K0_ICEW: DARN Iceland West (Stokkseyri),Key Parameters - R. Greenwald (JHU/APL)

DN_K0_KAPU: DARN Kapuskasing,Key Parameters - R. Greenwald (JHU/APL)

DN_K0_PACE: DARN PACE, Key Parameters - R. Greenwald (JHU/APL)

DN_K0_PYKK: DARN Pykkvibaer, Key Parameters - R. Greenwald (JHU/APL)

DN_K0_SASK: DARN Saskatoon, Key Parameters - R. Greenwald (JHU/APL)

DN_MAGN-L2-HIRES_G08: GOES-08 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G09: GOES-09 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G10: GOES-10 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G11: GOES-11 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G12: GOES-12 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G13: GOES-13 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G14: GOES-14 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G15: GOES-15 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G16: GOES-16 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G17: GOES-17 Magnetometer L2 - Rob Redmon, Paul Loto'aniu, Howard Singer (DOC/NOAA/NCEI and DOC/NOAA/NWS/SWPC respectively)

DN_MAGN-L2-HIRES_G18: GOES-18 Magnetometer L2 - Rob Redmon, Paul Loto'aniu (DOC/NOAA/NESDIS/NCEI/OGSSD/STP)

DN_MAGN-L2-HIRES_G19: GOES-19 Magnetometer L2 Geomagnetic Field 10 Hz Product with Complete Coordinate Frames - Rob Redmon, Paul Loto'aniu (DOC/NOAA/NESDIS/NCEI/OGSSD/STP)

DSCOVR_AT_DEF: DSCOVR Definitive Attitude - A. Szabo (NASA Goddard Space Flight Center)

DSCOVR_AT_PRE: DSCOVR Preliminary Attitude - A. Szabo (NASA Goddard Space Flight Center)

DSCOVR_COHO1HR_MERGED_MAG: DSCOVR merged hourly magnetic field and ephemeris data - Natalia Papitashvili (NASA/GSFC)

DSCOVR_H0_MAG: DSCOVR Fluxgate Magnetometer 1-sec Definitive Data - A. Koval (UMBC, NASA/GSFC)

DSCOVR_H1_FC: Isotropic Maxwellian parameters for solar wind protons. - Justin C. Kasper (Smithonian Astrophysical Observatory)

DSCOVR_HELIO1HR_POSITION: Position in heliocentric coordinates from SPDF Helioweb - Natalia Papitashvili (NASA/GSFC/SPDF)

DSCOVR_ORBIT_PRE: DSCOVR Predicted Orbit - A. Szabo (NASA Goddard Space Flight Center)

DYNAMO-2_DESA_NX02A-ESA-FLUX: Standard Resolution (15% DE/E) data (0.5eV to 1keV) - G. Collinson (NASA GSFC / Catholic University of America)

DAWN_HELIO1HR_POSITION

Description

No TEXT global attribute value.

Data Variable Descriptions

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DE1_1MIN_RIMS doi:10.48322/4e3s-bm07

Description

The data were provided by Dennis Gallagher (MSFC). The Retarding Ion Mass
Spectrometer (RIMS) consisted of a retarding potential analyzer for energy
analysis in series with a magnetic ion-mass spectrometer for mass analysis.
Multiple sensor heads permitted the determination of the thermal plasma flow
characteristics. This instrument was designed to operate in two basic
commandable modes: a high-altitude mode in which the density, temperature, and
bulk-flow characteristics of principally H+, He+, and O+ ions were measured; and
a low-altitude mode that concentrated on the composition in the 1- to 32-u
range. This investigation provided information on (1) the densities of H+, He+,
and O+ ions in the ionosphere, plasmasphere, plasma trough, and polar cap
(including the density distribution along the magnetic vector in the vicinity of
the satellite apogee); (2) the temperature of H+, He+, and O+ ions in the
ionosphere, plasmasphere, plasma trough, and polar cap (energy range 0-45 eV);
(3) the bulk flow velocities of H+, He+, and O+ in the plasmapause, plasma
trough and polar cap; (4) the changing character of the cold plasma density,
temperature, and bulk flow in regions of interaction with hot plasma such as at
the boundary between the plasmasphere and the ring current; and (5) the detailed
composition of ionospheric plasma in the 1-to 32-u range. He++ and O++ were also
measured. The instrument consisted of three detector heads. One looked out in
the radial direction, and the other two were along the plus and minus spin-axis
directions. Each detector had a 55-deg half-cone acceptance angle. The detector
heads had a gridded, weakly collimating aperture where the retarding analysis
was performed, followed by a parallel plate ceramic magnetic mass analyzer with
two separate exit slits corresponding to ion masses in the ratio 1:4. Ions
exiting from these slits were detected with electron multipliers. In the apogee
mode, the thermal particle fluxes were measured while the potential on a set of
retarding grids was stepped through a sequence of settings. In the perigee mode,
the retarding grids were grounded and the detector utilized a continuous
acceleration potential sweep that focused the mass ranges from 1 to 8, and 4 to
32 u. Time resolution was 16 msec. Additional details can be found in C. R.
Chappell et al., Space Sci. Instrum., v. 5, n. 4, p. 477, 1981.
Criterian for selecting data points to be fitted aperature bias = 0 must have at
least 10 or more non-zero points in rpa curve.  if less that 1.3 Re high voltage
monitor must be turned on maximum countr rate value must at least 5.0 must have
at least 4 points starting from end of rpa curve find 3 consecutive point of
increasing value, reset end of rpa curve to here make certain last point is 1
sigma above noise level (the points excluded in previous step), if not drop
point and check new last point, continue until criteria is met, must have at
least 3 points left starting at new end of selected rpa curve stop first point
greater that 80% of maximum of spin curve, if non found stop at last point less
that maximum, must have at least 3 points left change curve from count rate
curve to l**2 curve if number of points are 5 or less: do a linear least squares
fit (linfit) to the data, if the linear correlation coefficient (lcc) greater
than 0.800 then points will be used, if not, data set is discarded if number of
points are greater then 5: do a linfit to the bottom 5 and a linfit to the top 5
points, in 6 or more points do linfit to the middle 5, saving the lcc and slope
for each case. if all three lccs are less than 0.800 discard data set through a
series of tests find the set of 5 with the best lcc slope combination once set
of 5 has been selected add rest of points one at a time and redo linfit, if lcc
gets worse discard point otherwise keep it, do this until all points are checked
we now have the points to be used
Two Dynamics Explorer (DE) spacecraft were launched August 3, 1981, and placed
into coplanar polar orbits with DE-1 in a highly elliptical orbit and DE-2 in a
lower more circular orbit. The primary objective of the DE program was to
investigate magnetosphere-ionosphere-atmosphere coupling processes.
The DE mission provided a wealth of new information on a wide variety of
magnetospheric plasma wave phenomena including auroral kilometric radiation,
auroral hiss, Z mode radiation, narrow-band electromagnetic emissions associated
with equatorial upper hybrid waves, whistler mode emissions, wave-particle
interactions stimulated by ground VLF transmitters, equatorial ion
cyclotron.emissions, ion Bernstein mode emissions, and electric field turbulence
along the auroral field lines.

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DE1_2SEC_OA

Description

Dynamics Explorer 1 spacecraft was one of two satellites in the Dynamics
Explorer program.  The DE-1 and DE-2 satellites were launched by the same
vehicle so that their orbits would be coplanar, allowing two-point measurements
along magnetic field lines, for the purpose of studying coupling between the
magnetosphere, ionosphere, and upper atmosphere.  The DE-1 orbit was highly
elliptical with an apogee of 4.35 Re and a perigee of 500 km whereas the DE-2
spacecraft was placed in a much lower 300 x 1000 km altitude orbit. DE-1 was
spin stabilized with its spin axis normal to the plane of the orbit. DE-2 was
three axis stabilized with one face being nadir oriented. 
The study of field-aligned currents and MHD waves were the primary objectives of
the DE-1/2 magnetometer investigation. Comparison of the magnetometer data with
measurements of precipitating charged particles yielded new information on the
field-aligned current carriers.  In combination with the electric field
measurements, it was possible to determine the vertical Poynting Flux of
electromagnetic energy flowing between the magnetosphere and ionosphere and to
separate small-scale field-aligned currents from MHD waves through the
evaluation of the local ratio of the electric to magnetic field amplitudes in
these perturbations. The field-aligned current measurements and neutral
atmosphere observations also provided an opportunity for investigating
atmosphere-magnetosphere coupling and assessing the total rate of energy
transfer into the upper atmosphere.  Finally, the DE-1/2 magnetometer
investigation provided a vital service in so far as a knowledge of magnetic
field direction and intensity is essential to any number of space plasma science
investigations utilizing the various DE-1/2 particles and fields data sets. 
The DE-1 magnetic field (MAG-A) 6-second average resolution data set consists of
averages of the high resolution triaxial fluxgate measurements taken every 62.5
msec (i.e., 16 vectors/second).  The MAG-A data set consists of the three
components of the model magnetic field and difference field, B-Radial (Br),
B-Theta (Bth), and B-Phi (Bph), in *old* Geomagnetic Spherical (GMS)
Coordinates, and the difference field in local *new* Geographic Spherical (GGS)
and Geomagnetic Spherical (GMS) Coordinates, respectively, and the difference
field in local magnetic coordinates (b-para, b-parp1, b-parp2).  The R, Theta
and Phi axes are positive in the directions of increasing radial distance from
the center of the Earth (i.e., outward), increasing magnetic colatitude (i.e.,
southward) and increasing azimuth angle (i.e., magnetic east). The reference for
the MAGSAT magnetic field model is Langel et al., Geophys. Res. Lett., 7, 793,
1980. The following Orbit Attitude (OA) parameters are also included in the data
set: altitude, geographic latitude and longitude, magnetic local time, and
invariant latitude. The data are provided in daily files in ASCII format.
[updated by Robert.M.Candey@nasa.gov, 2006 Jan 17, per email dated Date: Thu, 18
Feb 99 17:08:59 JST From: iyemori@swdcgw.kugi.kyoto-u.ac.jp (Toshihiko_Iyemori)]
As described in Farthing et al. (1981), the DE-1 magnetometer had a digital
resolution of +1.5 nT in its low altitude, least sensitive mode. Two higher
sensitivity modes were used at higher altitudes with digital resolutions of
+0.25 nT and +0.02 nT, respectively. The data set consists of daily files from
81258 to 91049 in ASCII format. Each file contains all of the data available for
a given day.
The dominant source of error in the DE-1 magnetic field measurements is the
uncertainty in the attitude of the spacecraft. The DE-1 spacecraft was designed
to an attitude uncertainty specification of about 0.3 degree which appears to
have been met much of the time. As a rule of thumb each 0.1 degree in attitude
uncertainty near perigee corresponds to an error of approximately 100 nT in each
component of the field when the magnetic field measured at the sensors is
transferred to an inertial frame of reference or a model field is transferred
into the 0spacecraft frame and subtracted from the measured field.  For this
reason it is common for the residual, or delta-B field obtained by subtracting
the model field at low altitudes (i.e., high fields) to show a gradual shift of
several 100 nT from the start of a passage across the polar cap to the other
side.  (These slow shifts in the baselines of the vector field components do not
affect most scientific analyses, e.g., field-aligned current measurements, but
they can be effectively dealt with through modeling if need be.  At higher
altitudes the ambient field intensity is less and the uncertainty due to
attitude errors is correspondingly smaller.
The absolute accuracy of the DE-1 total magnetic field measurement has also been
evaluated through comparison with the precision vector/scalar magnetic field
observatories located on the ground which are used to monitor the geomagnetic
field. On the basis of such cross-comparisons utilizing DE-1 perigee data over
the life of the mission, R. Langel (private communication, 1994) found excellent
agreement between the MAG-A and ground-based observatory scalar data sets at the
20 to 40 nT level. 
In using any unfamiliar data set, caution is advised and tests to screen out
instrumental artifacts should be devised before reaching important conclusions.
De-spinning high sensitivity, boom mounted vector magnetometer data in high
fields (i.e., >1000 nT) frequently results in a readily observable residual
signal at the spin period and its harmonics. In the case of the DE-1
magnetometer measurements, the dominant causes of residual spin tone were found
to be small (0.1 to 0.01%) changes in the instrument scale factors and boom
bending of up to several tenths of a degree in response to varying thermal
inputs due to orbit/attitude driven changes in solar illumination (e.g.,
seasonal variations, eclipses, etc.). These effects were minimized through an
orbit by orbit calibration procedure which analyzed the residual spin tone
around apogee and perigee and adjusted the scale factors and sensor attitude
accordingly. Even after these in-flight calibration activities, residual spin
tone signals in the MAG-A data with amplitudes of tens of nanotesla are common
in high fields around perigee. The most probable cause of these residuals is the
transverse field dependence of fluxgate magnetometers in high fields which was
not well-appreciated at the time that DE-1/2 magnetometers were designed and
calibrated in the late 1970's. As discussed by Luhr et al. (1995) in regards to
the magnetometer on the low altitude, spin stabilized Freja spacecraft, this
non-linear effect can easily produce the residual spin frequency signals present
in the MAG-A data set. 
The MLT and ILAT algorithms were supplied by M. Sugiura (PI for the Magnetometer
Investigation) prior to launch and used in the generation of the Orbit-Attitude
database.
References:               
1. The Instrument Data File Set. URL http://pemrac.space.swri.edu/spds/data.html

Modification History

Initial Release

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DE1_62MS_MAGA-GMS

Description

Dynamics Explorer 1 spacecraft was one of two satellites in the Dynamics
Explorer program.  The DE-1 and DE-2 satellites were launched by the same
vehicle so that their orbits would be coplanar, allowing two-point measurements
along magnetic field lines, for the purpose of studying coupling between the
magnetosphere, ionosphere, and upper atmosphere.  The DE-1 orbit was highly
elliptical with an apogee of 4.35 Re and a perigee of 500 km whereas the DE-2
spacecraft was placed in a much lower 300 x 1000 km altitude orbit. DE-1 was
spin stabilized with its spin axis normal to the plane of the orbit. DE-2 was
three axis stabilized with one face being nadir oriented. 
The study of field-aligned currents and MHD waves were the primary objectives of
the DE-1/2 magnetometer investigation. Comparison of the magnetometer data with
measurements of precipitating charged particles yielded new information on the
field-aligned current carriers.  In combination with the electric field
measurements, it was possible to determine the vertical Poynting Flux of
electromagnetic energy flowing between the magnetosphere and ionosphere and to
separate small-scale field-aligned currents from MHD waves through the
evaluation of the local ratio of the electric to magnetic field amplitudes in
these perturbations. The field-aligned current measurements and neutral
atmosphere observations also provided an opportunity for investigating
atmosphere-magnetosphere coupling and assessing the total rate of energy
transfer into the upper atmosphere.  Finally, the DE-1/2 magnetometer
investigation provided a vital service in so far as a knowledge of magnetic
field direction and intensity is essential to any number of space plasma science
investigations utilizing the various DE-1/2 particles and fields data sets.  
The DE-1 magnetic field (MAG-A) high time resolution data set consists of
triaxial fluxgate measurements taken every 62.5 msec (i.e., 16 vectors/second). 
As described in Farthing et al. (1981), the DE-1 magnetometer had a digital
resolution of +1.5 nT in its low altitude, least sensitive mode. Two higher
sensitivity modes were used at higher altitudes with digital resolutions of
+0.25 nT and +0.02 nT, respectively. The MAG-A data set consists of the three
components of the magnetic field, B-Radial (Br), B-Theta (Bth), and B-Phi (Bph),
in Geomagnetic Spherical (GMS) Coordinates. This is a local Cartesian coordinate
system. The R, Theta and Phi axes are oriented relative to a MAGSAT magnetic
field model (Langel et al., 1980) positive in the directions of increasing
radial distance from the center of the Earth (i.e., outward), increasing
magnetic colatitude (i.e., southward) and increasing azimuth angle (i.e.,
magnetic east). The following Orbit Attitude (OA) parameters are also included
in the archive data set: model magnetic field in GMS coordinates; altitude of
the satellite; magnetic latitude and longitude; magnetic local time, and
invariant latitude. The data set consists of daily files from 81258 to 91049.
Each file contains all of the data available for a given day. If there were no
magnetometer data for a given time, the time record was left out. If there were
magnetometer data, but no orbit or model field data, a fill value of 9999999.0
was used for the missing values.  
The dominant source of error in the DE-1 magnetic field measurements is the
uncertainty in the attitude of the spacecraft. The DE-1 spacecraft was designed
to an attitude uncertainty specification of about 0.3 degree which appears to
have been met much of the time. As a rule of thumb each 0.1 degree in attitude
uncertainty near perigee corresponds to an error of approximately 100 nT in each
component of the field when the magnetic field measured at the sensors is
transferred to an inertial frame of reference or a model field is transferred
into the 0spacecraft frame and subtracted from the measured field.  For this
reason it is common for the residual, or delta-B field obtained by subtracting
the model field at low altitudes (i.e., high fields) to show a gradual shift of
several 100 nT from the start of a passage across the polar cap to the other
side.  (These slow shifts in the baselines of the vector field components do not
affect most scientific analyses, e.g., field-aligned current measurements, but
they can be effectively dealt with through modeling if need be.  At higher
altitudes the ambient field intensity is less and the uncertainty due to
attitude errors is correspondingly smaller.
The absolute accuracy of the DE-1 total magnetic field measurement has also been
evaluated through comparison with the precision vector/scalar magnetic field
observatories located on the ground which are used to monitor the geomagnetic
field. On the basis of such cross-comparisons utilizing DE-1 perigee data over
the life of the mission, R. Langel (private communication, 1994) found excellent
agreement between the MAG-A and ground-based observatory scalar data sets at the
20 to 40 nT level. 
On time scales comparable to or less than the DE-1 spin period, 6 sec, other
artifacts are present in the data set which must be considered for
somescientific investigations. Like most telemetered geophysical data, the
vector.components archived here suffer from occasional bad data points. These
spurious data entries were caused, for the most part, by noise introduced in the
satellite-receiving station telemetry link. Such bad data can usually be
recognized by workers familiar with such data sets. These are for the most part
single point data excursions which show no geophysical correlation between the
magnetic field components and the observations of plasma phenomena by the other
DE instruments. Similarly, there sometimes exist spurious data points in the
ancillary orbit/attitude database.  Some are obvious such as model magnetic
field values for which the sign values have been corrupted. Others, such as
occasional millisecond jumps in the time, produce small, unphysical
discontinuities in the processed field components. Small discontinuities are
also sometimes present at the point where the magnetometer changes mode due to
slight imperfections in calibration parameters which are independently
determined for each mode. (N.B., mode changes can be readily detected by the
change in the digital resolution of the data in an expanded vertical scale plot
of B versus time.) In using any unfamiliar data set, caution is advised and
tests to screen out instrumental artifacts should be devised before reaching
important conclusions.
De-spinning high sensitivity, boom mounted vector magnetometer data in high
fields (i.e., >1000 nT) frequently results in a readily observable residual
signal at the spin period and its harmonics. In the case of the DE-1
magnetometer measurements, the dominant causes of residual spin tone were found
to be small (0.1 to 0.01%) changes in the instrument scale factors and boom
bending of up to several tenths of a degree in response to varying thermal
inputs due to orbit/attitude driven changes in solar illumination (e.g.,
seasonal variations, eclipses, etc.). These effects were minimized through an
orbit by orbit calibration procedure which analyzed the residual spin tone
around apogee and perigee and adjusted the scale factors and sensor attitude
accordingly. Even after these in-flight calibration activities, residual spin
tone signals in the MAG-A data with amplitudes of tens of nanotesla are common
in high fields around perigee. The most probable cause of these residuals is the
transverse field dependence of fluxgate magnetometers in high fields which was
not well-appreciated at the time that DE-1/2 magnetometers were designed.and
calibrated in the late 1970's. As discussed by Luhr et al. (1995) in regards to
the magnetometer on the low altitude, spin stabilized Freja spacecraft, this
non-linear effect can easily produce the residual spin frequency signals present
in the MAG-A data set.

Data Variable Descriptions

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DE1_6SEC_MAGAGMS doi:10.48322/ps14-8x77

Description

Dynamics Explorer 1 spacecraft was one of two satellites in the Dynamics
Explorer program.  The DE-1 and DE-2 satellites were launched by the same
vehicle so that their orbits would be coplanar, allowing two-point measurements
along magnetic field lines, for the purpose of studying coupling between the
magnetosphere, ionosphere, and upper atmosphere.  The DE-1 orbit was highly
elliptical with an apogee of 4.35 Re and a perigee of 500 km whereas the DE-2
spacecraft was placed in a much lower 300 x 1000 km altitude orbit. DE-1 was
spin stabilized with its spin axis normal to the plane of the orbit. DE-2 was
three axis stabilized with one face being nadir oriented. 
The study of field-aligned currents and MHD waves were the primary objectives of
the DE-1/2 magnetometer investigation. Comparison of the magnetometer data with
measurements of precipitating charged particles yielded new information on the
field-aligned current carriers.  In combination with the electric field
measurements, it was possible to determine the vertical Poynting Flux of
electromagnetic energy flowing between the magnetosphere and ionosphere and to
separate small-scale field-aligned currents from MHD waves through the
evaluation of the local ratio of the electric to magnetic field amplitudes in
these perturbations. The field-aligned current measurements and neutral
atmosphere observations also provided an opportunity for investigating
atmosphere-magnetosphere coupling and assessing the total rate of energy
transfer into the upper atmosphere.  Finally, the DE-1/2 magnetometer
investigation provided a vital service in so far as a knowledge of magnetic
field direction and intensity is essential to any number of space plasma science
investigations utilizing the various DE-1/2 particles and fields data sets. 
The DE-1 magnetic field (MAG-A) 6-second average resolution data set consists of
averages of the high resolution triaxial fluxgate measurements taken every 62.5
msec (i.e., 16 vectors/second).  The MAG-A data set consists of the three
components of the model magnetic field and difference field, B-Radial (Br),
B-Theta (Bth), and B-Phi (Bph), in *old* Geomagnetic Spherical (GMS)
Coordinates, and the difference field in local *new* Geographic Spherical (GGS)
and Geomagnetic Spherical (GMS) Coordinates, respectively, and the difference
field in local magnetic coordinates (b-para, b-parp1, b-parp2).  The R, Theta
and Phi axes are positive in the directions of increasing radial distance from
the center of the Earth (i.e., outward), increasing magnetic colatitude (i.e.,
southward) and increasing azimuth angle (i.e., magnetic east). The reference for
the MAGSAT magnetic field model is Langel et al., Geophys. Res. Lett., 7, 793,
1980. The following Orbit Attitude (OA) parameters are also included in the data
set: altitude, geographic latitude and longitude, magnetic local time, and
invariant latitude. The data are provided in daily files in ASCII format.
[updated by Robert.M.Candey@nasa.gov, 2006 Jan 17, per email dated Date: Thu, 18
Feb 99 17:08:59 JST From: iyemori@swdcgw.kugi.kyoto-u.ac.jp (Toshihiko_Iyemori)]
As described in Farthing et al. (1981), the DE-1 magnetometer had a digital
resolution of +1.5 nT in its low altitude, least sensitive mode. Two higher
sensitivity modes were used at higher altitudes with digital resolutions of
+0.25 nT and +0.02 nT, respectively. The data set consists of daily files from
81258 to 91049 in ASCII format. Each file contains all of the data available for
a given day. 
The dominant source of error in the DE-1 magnetic field measurements is the
uncertainty in the attitude of the spacecraft. The DE-1 spacecraft was designed
to an attitude uncertainty specification of about 0.3 degree which appears to
have been met much of the time. As a rule of thumb each 0.1 degree in attitude
uncertainty near perigee corresponds to an error of approximately 100 nT in each
component of the field when the magnetic field measured at the sensors is
transferred to an inertial frame of reference or a model field is transferred
into the 0spacecraft frame and subtracted from the measured field.  For this
reason it is common for the residual, or delta-B field obtained by subtracting
the model field at low altitudes (i.e., high fields) to show a gradual shift of
several 100 nT from the start of a passage across the polar cap to the other
side.  (These slow shifts in the baselines of the vector field components do not
affect most scientific analyses, e.g., field-aligned current measurements, but
they can be effectively dealt with through modeling if need be.  At higher
altitudes the ambient field intensity is less and the uncertainty due to
attitude errors is correspondingly smaller.
The absolute accuracy of the DE-1 total magnetic field measurement has also been
evaluated through comparison with the precision vector/scalar magnetic field
observatories located on the ground which are used to monitor the geomagnetic
field. On the basis of such cross-comparisons utilizing DE-1 perigee data over
the life of the mission, R. Langel (private communication, 1994) found excellent
agreement between the MAG-A and ground-based observatory scalar data sets at the
20 to 40 nT level. 
In using any unfamiliar data set, caution is advised and tests to screen out
instrumental artifacts should be devised before reaching important conclusions.
De-spinning high sensitivity, boom mounted vector magnetometer data in high
fields (i.e., >1000 nT) frequently results in a readily observable residual
signal at the spin period and its harmonics. In the case of the DE-1
magnetometer measurements, the dominant causes of residual spin tone were found
to be small (0.1 to 0.01%) changes in the instrument scale factors and boom
bending of up to several tenths of a degree in response to varying thermal
inputs due to orbit/attitude driven changes in solar illumination (e.g.,
seasonal variations, eclipses, etc.). These effects were minimized through an
orbit by orbit calibration procedure which analyzed the residual spin tone
around apogee and perigee and adjusted the scale factors and sensor attitude
accordingly. Even after these in-flight calibration activities, residual spin
tone signals in the MAG-A data with amplitudes of tens of nanotesla are common
in high fields around perigee. The most probable cause of these residuals is the
transverse field dependence of fluxgate magnetometers in high fields which was
not well-appreciated at the time that DE-1/2 magnetometers were designed and
calibrated in the late 1970's. As discussed by Luhr et al. (1995) in regards to
the magnetometer on the low altitude, spin stabilized Freja spacecraft, this
non-linear effect can easily produce the residual spin frequency signals present
in the MAG-A data set. 
The MLT and ILAT algorithms were supplied by M. Sugiura (PI for the Magnetometer
Investigation) prior to launch and used in the generation of the Orbit-Attitude
database.

Data Variable Descriptions

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DE1_PWI_LFC-SPECTRA doi:10.48322/hx4p-3v35

Description

S. D. Shawhan, D. A. Gurnett, D. L. Odem, R. A. Helliwell, and C. G. Park, The
plasma wave and quasi-static electric field instrument (PWI) for Dynamics
Explorer-A, Space Sci. Instrumen., 5, 535, 1981.
Two Dynamics Explorer (DE) spacecraft were launched August 3, 1981, and placed
into coplanar polar orbits with DE-1 in a highly elliptical orbit and DE-2 in a
lower more circular orbit. The primary objective of the DE program was to
investigate magnetosphere-ionosphere-atmosphere coupling processes.
The DE mission provided a wealth of new information on a wide variety of
magnetospheric plasma wave phenomena including auroral kilometric radiation,
auroral hiss, Z mode radiation, narrow-band electromagnetic emissions associated
with equatorial upper hybrid waves, whistler mode emissions, wave-particle
interactions stimulated by ground VLF transmitters, equatorial ion cyclotron
emissions, ion Bernstein mode emissions, and electric field turbulence along the
auroral field lines. 
This file contains calibrated, full resolution, data from the DE-1 Plasma Wave
Instrument (PWI).  This instrument was designed and built by the plasma wave
group at The University of Iowa, Department of Physics and Astronomy, in
collaboration with investigators at Stanford University's STAR Laboratory.  It
measured plasma wave phenomena and quasi-static electric fields using paired
combinations of five PWI sensors: a 200m tip-to-tip long wire electric antenna
deployed in the spacecraft spin plane, a 9m tip-to-tip tubular electric antenna
deployed along the spacecraft spin axis, a short 0.6m electric antenna, mounted
on the boom and oriented parallel to the long wire antenna, a magnetic loop
antenna mounted on the boom and oriented to measure the component of the
magnetic field parallel to the long wire antenna, and a magnetic search coil
antenna, also mounted on a boom and oriented to measure the magnetic field
parallel to the spacecraft spin axis.
The PWI main electronics unit consisted of a Step Frequency Correlator (SFC), a
Low Frequency Correlator (LFC), a Wideband Analog Receiver (WBR) and a Linear
Wave Receiver (LWR).  Only the LFC data are included in these files.  The SFC
data were provided in a companion fileset.  A dataset containing available high
rate WBR LWR data may be provided in future archive products.
The LFC consisted of two receivers (LFR-A and LFR-B) with 8 analog channels
each. The analog channels were centered at 1.78, 3.12, 5.62, 10.0, 17.8, 31.2,
56.2 and 100 Hz.  Each channel's band-edge was at +/-15% of the center value. 
Each LFR in the LFC could be connected to either the Ex, Es, Ez, or H antenna
during an 8 second major frame.  In addition, the Low Frequency Correlator
provided in-phase and quadrature-phase correlations of signals from any selected
antenna pair.  Phase data are not provided in this file set.
For a detailed description of the Plasma Wave Instrument, the reader is referred
to the Space Science Instrumentation referenece above.

Data Variable Descriptions

Spin Plane E-Field (LFC Ex) Spectra, 200 meter antenna, 104 Hz to 409 kHz [data monotonically sorted based on dependencies] [Ex_Spectra_Reorder]

These data are collected via the Long Wire Antenna (Ex) which has a frequency
response range of DC to 2 MHz.  It is constructed of two 100 meter wires
deployed in the spacecraft spin plane held in place by a 5 g tip mass. The
conductor is made of BeCu wire with 7 strands of 5-mil diam each.  The effective
electrical length is 173.1 meters DC and 101.4 meters AC.

[CDAWEB PLOTS NOT SUPPORTED] Spin Plane E-Field (LFC Ex) Spectra, 200 meter antenna, 104 Hz to 409 kHz [Ex_Spectra]

These data are collected via the Long Wire Antenna (Ex) which has a frequency
response range of DC to 2 MHz.  It is constructed of two 100 meter wires
deployed in the spacecraft spin plane held in place by a 5 g tip mass. The
conductor is made of BeCu wire with 7 strands of 5-mil diam each.  The effective
electrical length is 173.1 meters DC and 101.4 meters AC.

Spin Axis E-Field (LFC Ez) Spectra, 8 meter antenna, 104 Hz to 409 kHz [data monotonically sorted based on dependencies] [Ez_Spectra_Reorder]

These data are collected via the Tubular Electric Antenna (Ez) which has a
frequency response range of DC to 2 MHz.  It is constructed of two 4 meter tubes
deployed along the spacecraft spin axis.  The conductor is silver plated BeCu
2.8 cm diameter elements and has an effective electrical length of 8.0 meters DC
and 5.0 meters AC.

[CDAWEB PLOTS NOT SUPPORTED] Spin Axis E-Field (LFC Ez) Spectra, 8 meter antenna, 104 Hz to 409 kHz [Ez_Spectra]

These data are collected via the Tubular Electric Antenna (Ez) which has a
frequency response range of DC to 2 MHz.  It is constructed of two 4 meter tubes
deployed along the spacecraft spin axis.  The conductor is silver plated BeCu
2.8 cm diameter elements and has an effective electrical length of 8.0 meters DC
and 5.0 meters AC.

Spin Plane E-Field (LFC Es) Spectra, 0.6 meter antenna, 104 Hz to 100 kHz [data monotonically sorted based on dependencies] [Es_Spectra_Reorder]

These data are collected via the Short Electric Antenna (Es) which has a
response range of 20 Hz to 100 kHz.  It's constructed of two 10 cm diameter wire
spheres separated by 0.6 meters with fiberglass booms.  It is mounted on the PWI
6 meter boom oriented parallel to the long wire antenna (Ex).  It's effective
electrical length is 0.6 meters for AC signals.  The LFC samples frequences
above the response range of this antenna, data above 100 kHz should be used with
care.

[CDAWEB PLOTS NOT SUPPORTED] Spin Plane E-Field (LFC Es) Spectra, 0.6 meter antenna, 104 Hz to 100 kHz [Es_Spectra]

These data are collected via the Short Electric Antenna (Es) which has a
response range of 20 Hz to 100 kHz.  It's constructed of two 10 cm diameter wire
spheres separated by 0.6 meters with fiberglass booms.  It is mounted on the PWI
6 meter boom oriented parallel to the long wire antenna (Ex).  It's effective
electrical length is 0.6 meters for AC signals.  The LFC samples frequences
above the response range of this antenna, data above 100 kHz should be used with
care.

Spin Axis B-Field Spectra (LFC H), search coil, 1.8 to 100 Hz [data monotonically sorted based on dependencies] [H_Spectra_Reorder]

These data are collected via the Magnetic Search Coil (H) which has a response
range of 1 Hz to 1 kHz.  It's constructed of two coils of 5000 turns of #40
copper wire on a 40 cm laminated high-permeability core enclosed in a fiberglass
housing and coated with conducting material

[CDAWEB PLOTS NOT SUPPORTED] Spin Axis B-Field Spectra (LFC H), search coil, 1.8 to 100 Hz [H_Spectra]

These data are collected via the Magnetic Search Coil (H) which has a response
range of 1 Hz to 1 kHz.  It's constructed of two coils of 5000 turns of #40
copper wire on a 40 cm laminated high-permeability core enclosed in a fiberglass
housing and coated with conducting material

---> [CDAWEB PLOTS NOT SUPPORTED] Time offsets (fixed) from the Epoch time for each spectra measurement in a sweep [SubSweepTime]

If sub-sweep timing is not important to your application, this value can be
ignored. Otherwise for each measurement add this time to the Epoch value for the
record.  There is one offset in this array for each measurement in the sweep

The Filter Receiver used to measure the Ex Antenna output (1=A,2=B,3=both) [Ex_Receivers]

Low Frequency Correlator has two independent Filter Receivers, labeled 'A' and
'B'. This variable records which of the filter receivers were connected to the
Ex antenna during the collection of each record.  This field will read: Ƈ' if
FR-A was connected to Ex, ƈ' if FR-B was connected to Ex, and Ɖ' if both were
used at different times during the 32 second sweep period.

---> The Filter Receivers used to measure the Es Antenna output [Es_Receivers]

Low Frequency Correlator has two independent Filter Receivers, labeled 'A' and
'B'. This variable records which of the filter receivers were connected to the
Es antenna during the collection of each record.  This field will read: Ƈ' if
FR-A was connected to Es, ƈ' if FR-B was connected to Es, and Ɖ' if both were
used at different times during the 32 second sweep period.

---> The Filter Receivers used to measure the Ez Antenna output [Ez_Receivers]

Low Frequency Correlator has two independent Filter Receivers, labeled 'A' and
'B'. This variable records which of the filter receivers were connected to the
Ez antenna during the collection of each record.  This field will read: Ƈ' if
FR-A was connected to Ez, ƈ' if FR-B was connected to Ez, and Ɖ' if both were
used at different times during the 32 second sweep period.

---> The Filter Receivers used to measure the H Antenna output [H_Receivers]

Low Frequency Correlator has two independent Filter Receivers, labeled 'A' and
'B'. This variable records which of the filter receivers were connected to the H
antenna during the collection of each record.  This field will read: Ƈ' if FR-A
was connected to B, ƈ' if FR-B was connected to B, and Ɖ' if both were used at
different times during the 32 second sweep period.

Integer combining all data quality flags (0 = no issues detected) [Quality_Flag]

A bitwise OR'ing of all known issue values for this record.  At present none are
defined so this field should always read 0.

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DE1_PWI_OR-AT doi:10.48322/wma0-gq05

Description

S. D. Shawhan, D. A. Gurnett, D. L. Odem, R. A. Helliwell, and C. G. Park, The
plasma wave and quasi-static electric field instrument (PWI) for Dynamics
Explorer-A, Space Sci. Instrumen., 5, 535, 1981.
Two Dynamics Explorer (DE) spacecraft were launched August 3, 1981, and placed
into coplanar polar orbits with DE-1 in a highly elliptical orbit and DE-2 in a
lower more circular orbit. The primary objective of the DE program was to
investigate magnetosphere-ionosphere-atmosphere coupling processes.
The DE mission provided a wealth of new information on a wide variety of
magnetospheric plasma wave phenomena including auroral kilometric radiation,
auroral hiss, Z mode radiation, narrow-band electromagnetic emissions associated
with equatorial upper hybrid waves, whistler mode emissions, wave-particle
interactions stimulated by ground VLF transmitters, equatorial ion cyclotron
emissions, ion Bernstein mode emissions, and electric field turbulence along the
auroral field lines. 
This file contains 8 second resolution emphemeris and spacecraft attitude
parameters that coincide with DE-1 telemetry frames containing PWI lowrate data.
 These parameters are not to be taken as an authoritative set, but are
convenient when working with PWI science data products.  Most of these data are
provided in the Geocentric Equatorial Inertial (GEI) TOD reference frame.  The Z
axis of the GEI frame is parallel to Earth's spin axis; the X axis points
towards the First Point of Aries with the Y axis aligned so as to generate a
right-handed coordinate system.
For a detailed description of the Plasma Wave Instrument, the reader is referred
to the Space Science Instrumentation referenece above.

Data Variable Descriptions

GEI Satallite Velocity Vector [GEI_velocity]

GEI (Geocentric Equatorial Inertial) Satallite Velocity Vector (km/sec).  The
order of the vector components is v(x), v(y), v(z).

Altitude above the spheroid Earth [Altitude]

Altitude above a spheroid Earth, not above the geoid

Geographic latitude of subsatellite point [GLAT]

Geographic latitude of subsatellite point in dgreees

Geographic longitude of the satellite [GLON]

Geographic longitude of the satellite in dgreees

Magnetic Local Time [MLT]

MLT was defined via the conventional Solar Magnetic frame.

McIlwain's shell parameter (L) [L_Shell]

Distance from the center of the Earth at which the spacecraft's current field
line crosses the equatorial plane (model derived).

Current Spacecraft Field Line Footprint's Geomagnetic Latitude [ILAT]

From https://sscweb.gsfc.nasa.gov:  For any point in space one can trace a 
B-field line to the Earth's surface, assuming it is a centered dipole field. The
Geomagnetic latitude of this foot point is labelled as the Invariant Latitude
along the entire field line. The dipole L-value is closely related to this
invariant latitude; L=1/(Cos(Lat))^2, and physically connotes the distance (in
Earth radii) of the 'top of the field line' from Earth center.

Magnetic field strength [B_Magnitude]

The measured magnetic field strength.  Any descrepency between these data and
those provided by the magnetometer instrument's own files should be resolved in
favor of the latter.  See 'Magnetic Field Observations on DE-A and -B', W. H.
Farthing, et al., Space Science Instrumentation 5 (1981) for more information

GEI magnetic field vector, B(x), B(y), B(z) [GEI_B_vec]

GEI (Geocentric Equatorial Inertial) Magnetic Vector in nanoTesla.  The order of
the vector components is B(x), B(y), B(z).  Any descrepency between these data
and those provided by the magnetometer instrument's own files should be resolved
in favor of the latter.  See 'Magnetic Field Observations on DE-A and -B', W. H.
Farthing, et al., Space Science Instrumentation 5 (1981) for more information

Orbit Number [Orbit_Number]

The orbit number from PWI archive files.

Spacecraft Position in GEI coordinates [GEI_position]

Spacecraft Position in GEI coordinates, the order of the coordinates is X, Y, Z

GEI satellite velocity relative to a rotating atmosphere. [GEI_rel_vel]

GEI (Geocentric Equatorial Inertial) Satellite Velocity Vector (km/sec) relative
to the rotatingatmosphere

Angle between the Velocity Vector and the Spacecraft x-axis [Spin_Angle]

Phase angle of spin measured from the velocity vector to the +x-axis of the
spacecraft in degrees

Sunlight/Darkness flag, 0 = Darkness, 1 = Sunlight [Sunlight]

Sunlight/Darkness: 0 = Darkness, 1 = Sunlight

Geocentric radial distance in Earth Radii [Re]

Geocentric radial distance in Earth Radii. Here 1 Re = 6378.2 km

Magnetic Latitude in degrees [MLAT]

Magnetic Latitude in dgreees (Derived)

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DE1_PWI_SFC-SPECTRA doi:10.48322/cb14-a164

Description

S. D. Shawhan, D. A. Gurnett, D. L. Odem, R. A. Helliwell, and C. G. Park, The
plasma wave and quasi-static electric field instrument (PWI) for Dynamics
Explorer-A, Space Sci. Instrumen., 5, 535, 1981.
Two Dynamics Explorer (DE) spacecraft were launched August 3, 1981, and placed
into coplanar polar orbits with DE-1 in a highly elliptical orbit and DE-2 in a
lower more circular orbit. The primary objective of the DE program was to
investigate magnetosphere-ionosphere-atmosphere coupling processes.
The DE mission provided a wealth of new information on a wide variety of
magnetospheric plasma wave phenomena including auroral kilometric radiation,
auroral hiss, Z mode radiation, narrow-band electromagnetic emissions associated
with equatorial upper hybrid waves, whistler mode emissions, wave-particle
interactions stimulated by ground VLF transmitters, equatorial ion
cyclotron.emissions, ion Bernstein mode emissions, and electric field turbulence
along the auroral field lines. 
This file contains calibrated, full resolution, data from the DE-1 Plasma Wave
Instrument (PWI).  This instrument was designed and built by the plasma wave
group at The University of Iowa, Department of Physics and Astronomy, in
collaboration with investigators at Stanford University's STAR Laboratory.  It
measured plasma wave phenomena and quasi-static electric fields using paired
combinations of five PWI sensors: a 200m tip-to-tip long wire electric antenna
deployed in the spacecraft spin plane, a 9m tip-to-tip tubular electric antenna
deployed along the spacecraft spin axis, a short 0.6m electric antenna, mounted
on the boom and oriented parallel to the long wire antenna, a magnetic loop
antenna mounted on the boom and oriented to measure the component of the
magnetic field parallel to the long wire antenna, and a magnetic search coil
antenna, also mounted on a boom and oriented to measure the magnetic field
parallel to the spacecraft spin axis.
The PWI main electronics unit consisted of a Step Frequency Correlator (SFC), a
Low Frequency Correlator (LFC), a Wideband Analog Receiver (WBR) and a Linear
Wave Receiver (LWR).  Only the SFC data are included in these files.  The LFC
data were provided in a companion fileset.  A dataset containing available high
rate WBR LWR data may be provided in the future.
The SFC consisted of two Step Frequency Receivers (SFR-A and SFR-B) which
provided amplitude  measurements of the electric and magnetic fields from 100 Hz
to 400 kHz and in-phase and quadrature-phase correlations of signals from any
selected antenna pair.  Phase data are not provided in this file set.
For a detailed description of the Plasma Wave Instrument, the reader is referred
to the Space Science Instrumentation referenece above.

Data Variable Descriptions

Spin Plane E-Field (SFC Ex) Spectra, 200 meter antenna, 104 Hz to 409 kHz [data monotonically sorted based on dependencies] [Ex_Spectra_Reorder]

These data are collected via the Long Wire Antenna (Ex) which has a frequency
response range of DC to 2 MHz.  It is constructed of two 100 meter wires
deployed in the spacecraft spin plane held in place by a 5 g tip mass. The
conductor is made of BeCu wire with 7 strands of 5-mil diam each.  The effective
electrical length is 173.1 meters DC and 101.4 meters AC.

[CDAWEB PLOTS NOT SUPPORTED] Spin Plane E-Field (SFC Ex) Spectra, 200 meter antenna, 104 Hz to 409 kHz [Ex_Spectra]

These data are collected via the Long Wire Antenna (Ex) which has a frequency
response range of DC to 2 MHz.  It is constructed of two 100 meter wires
deployed in the spacecraft spin plane held in place by a 5 g tip mass. The
conductor is made of BeCu wire with 7 strands of 5-mil diam each.  The effective
electrical length is 173.1 meters DC and 101.4 meters AC.

Spin Axis E-Field (SFC Ez) Spectra, 8 meter antenna, 104 Hz to 409 kHz [data monotonically sorted based on dependencies] [Ez_Spectra_Reorder]

These data are collected via the Tubular Electric Antenna (Ez) which has a
frequency response range of DC to 2 MHz.  It is constructed of two 4 meter tubes
deployed along the spacecraft spin axis.  The conductor is silver plated BeCu
2.8 cm diameter elements and has an effective electrical length of 8.0 meters DC
and 5.0 meters AC.

[CDAWEB PLOTS NOT SUPPORTED] Spin Axis E-Field (SFC Ez) Spectra, 8 meter antenna, 104 Hz to 409 kHz [Ez_Spectra]

These data are collected via the Tubular Electric Antenna (Ez) which has a
frequency response range of DC to 2 MHz.  It is constructed of two 4 meter tubes
deployed along the spacecraft spin axis.  The conductor is silver plated BeCu
2.8 cm diameter elements and has an effective electrical length of 8.0 meters DC
and 5.0 meters AC.

Spin Plane E-Field (SFC Es) Spectra, 0.6 meter antenna, 104 Hz to 100 kHz [data monotonically sorted based on dependencies] [Es_Spectra_Reorder]

These data are collected via the Short Electric Antenna (Es) which has a
response range of 20 Hz to 100 kHz.  It's constructed of two 10 cm diameter wire
spheres separated by 0.6 meters with fiberglass booms.  It is mounted on the PWI
6 meter boom oriented parallel to the long wire antenna (Ex).  It's effective
electrical length is 0.6 meters for AC signals.  The SFC samples frequences
above the response range of this antenna, data above 100 kHz should be used with
care.

[CDAWEB PLOTS NOT SUPPORTED] Spin Plane E-Field (SFC Es) Spectra, 0.6 meter antenna, 104 Hz to 100 kHz [Es_Spectra]

These data are collected via the Short Electric Antenna (Es) which has a
response range of 20 Hz to 100 kHz.  It's constructed of two 10 cm diameter wire
spheres separated by 0.6 meters with fiberglass booms.  It is mounted on the PWI
6 meter boom oriented parallel to the long wire antenna (Ex).  It's effective
electrical length is 0.6 meters for AC signals.  The SFC samples frequences
above the response range of this antenna, data above 100 kHz should be used with
care.

Spin Plane B-Field (SFC B) Spectra, 1.0 m**2 loop antenna, 104 to 409 kHz [data monotonically sorted based on dependencies] [B_Spectra_Reorder]

These data are collected via the Magnetic Loop Antenna (B) which has a frequency
response range of 100 Hz to 35 kHz for dB/dt and 35 kHz to 400 kHz response for
B.  It is constructed of a single loop of aluminum tubing of 0.8 by 1.25 meters
in size covering 1.0 m^2 area and is mounted on the PWI 6 meter boom oriented to
measure the spin-modulated component of B parallel to the long wire antenna, Ex.

[CDAWEB PLOTS NOT SUPPORTED] Spin Plane B-Field (SFC B) Spectra, 1.0 m**2 loop antenna, 104 to 409 kHz [B_Spectra]

These data are collected via the Magnetic Loop Antenna (B) which has a frequency
response range of 100 Hz to 35 kHz for dB/dt and 35 kHz to 400 kHz response for
B.  It is constructed of a single loop of aluminum tubing of 0.8 by 1.25 meters
in size covering 1.0 m^2 area and is mounted on the PWI 6 meter boom oriented to
measure the spin-modulated component of B parallel to the long wire antenna, Ex.

---> [CDAWEB PLOTS NOT SUPPORTED] Time offsets (fixed) from the Epoch time for each spectra measurement in a sweep [SubSweepTime]

If sub-sweep timing is not important to your application, this value can be
ignored. Otherwise for each measurement add this time to the Epoch value for the
record.  There is one offset in this array for each measurement in the sweep

The SFR Receivers used to measure the Ex Antenna output (1=A,2=B,3=both) [Ex_Receivers]

Step Frequency Correlator has two independent Step Frequency Receivers, labeled
'A' and 'B'. This variable records which of the SFR receivers were connected to
the Ex antenna during the collection of each record.  This field will read: Ƈ'
if SFR-A was connected to Ex, ƈ' if SFR-B was connected to Ex, and Ɖ' if both
were used at different times during the 32 second sweep period.

---> The SFR Receivers used to measure the Ez Antenna output [Ez_Receivers]

Step Frequency Correlator has two independent Step Frequency Receivers, labeled
'A' and 'B'. This variable records which of the SFR receivers were connected to
the Ez antenna during the collection of each record.  This field will read: Ƈ'
if SFR-A was connected to Ez, ƈ' if SFR-B was connected to Ez, and Ɖ' if both
were used at different times during the 32 second sweep period.

---> The SFR Receivers used to measure the Es Antenna output [Es_Receivers]

Step Frequency Correlator has two independent Step Frequency Receivers, labeled
'A' and 'B'. This variable records which of the SFR receivers were connected to
the Es antenna during the collection of each record.  This field will read: Ƈ'
if SFR-A was connected to Es, ƈ' if SFR-B was connected to Es, and Ɖ' if both
were used at different times during the 32 second sweep period.

---> The SFR Receivers used to measure the B Antenna output [B_Receivers]

Step Frequency Correlator has two independent Step Frequency Receivers, labeled
'A' and 'B'. This variable records which of the SFR receivers were connected to
the B antenna during the collection of each record.  This field will read: Ƈ'
if SFR-A was connected to B, ƈ' if SFR-B was connected to B, and Ɖ' if both
were used at different times during the 32 second sweep period.

---> Wideband (waveform) data availability status [WBR_xmit]

PWI Waveform data were transmitted directly from DE-1 without going through the
standard telemetry stream.  This status field will read 0 if the wideband
transmitter was off during this time period and thus waveform data were not
transmitted. A 1 in this field indicates the transmitter was on and that
waveform data may be available.

Integer combining all data quality flags (0 = no issues detected) [Quality_Flag]

A bitwise OR'ing of all known issue values for this record.  The following issue
values are defined.  (0x2: Attenuation Mode)  If this value is present the
measurements are less sensetive than normal due to the input being attenuated by
30 dB.  Though the data are still calibrated they do not have the same contrast
as data collected in the un-attenuated state.  (0x1: Gain Toggle Mode) If this
value is present it means that the SFC was toggling attenuation states every 1/2
second.  Measurements collected in the first half of the second are not
attenuated.  Measurements collected in the last half were attenuated by 30 dB. 
To achieve a single calibrated state for a single SFR band in a record the
attenuated measurements have been dropped.  The final quality flag is a bitwise
OR'ing of all issue values.

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DE2_62MS_VEFIMAGB doi:10.48322/ha70-4305

Description

This data set is a combination of the VEFI and MAGB high resolution data sets in
SPC coordinates submitted to NSSDC.  The following OA parameters have been added
to the data set:  Model magnetic field in SPC coordinates, altitude of the
satellite, geographic latitude and longitude, magnetic local time, and invariant
latitude.  The VEFI data set is described in the file VEFIVOLDESC.SFD and the
MAGB data set is described in the file MAGBVOLDESC.SFD, these files are portions
of the SFDU metadata files submitted with the VEFI and MAGB data to NSSDC and
are included in each volume of this data set.  
This data set consists of daily files from day 81227 to day 83047.  Each file
contains all the data available for a given day.
  During the merging of the data sets it was found that although VEFI and MAGB
should cover the same time spans, they do not, due perhaps to the fact that the
original MAGB high resolution data set was created on the DE Sigma-9 using the
DE telemetry tapes, while the VEFI high resolution data set was created on the
DE MicroVAX system using the DE telemetry data base on optical disk.  In order
to keep the largest amount of data possible, the merged data set includes all
the available VEFI and MAGB data, for those times when VEFI data was available
but MAGB was not (6.54%), a fill data value of 9999999. was given to the MAGB
data and for those times when MAGB data was available but VEFI was not (6.87%),
the fill data value was assigned to the VEFI data.  Times for which both VEFI
and MAGB data were fill values in the original data sets were not included in
the merged data set.  There were also times when certain OA parameters were fill
values in the OA data base and they are therefore also fill values in this
merged data set.  The model magnetic field had fill values for 8.55% of the
data.  Statistics were not kept for the other OA parameters.  Each daily file
contains a record per measurement.  The total number of records in each file
varies depending on the amount of data available for a given day.
The model magnetic field is MAGSAT model (Langel et al., GRL, 7, 793, 1980) 
https://spdf.gsfc.nasa.gov/pub/data/de/de2/magnetic_fields_magb/data_format_desc
ription.txt and
https://spdf.gsfc.nasa.gov/pub/data/de/de2/magnetic_electric_fields_vefi_magb/de
scription_dc_500ms.txt R.A. Langel at al., Initial Geomagnetic Field Model From
MAGSAT vector data, GRL, 7,793-796, 1980. 
 Adjusted field removes contact potentials due to work function differences of
the sensor surfaces, an imbalance of photoelectron currents, spacecraft sheath
effects, and other effects. See 
https://spdf.gsfc.nasa.gov/pub/data/de/de2/magnetic_electric_fields_vefi_magb/VE
FI_instrument_data.txt  Non-adjusted when they couldn't compute the contact
potential

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DE2_AC500MS_VEFI doi:10.48322/x1km-9q17
Proper citations should include the "Accessed on date" in the form .

Description

The Vector Electric Field Instrument (VEFI) used flight-proven double-probe
techniques with 20-m baselines to obtain measurements of dc electric fields.
This electric field investigation had the following objectives: (1) to obtain
accurate and comprehensive triaxial dc electric field measurements at
ionospheric altitudes in order to refine the basic spatial patterns, define the
large-scale time history of these patterns, and study the small-scale temporal
and spatial variations within the overall patterns; (2) to study the degree to
which and in what region the electric field projects to the equatorial plane;
(3) to obtain measurements of extreme low frequency (ELF) and lower frequency
irregularity structures; and (4) to perform numerous correlative studies. The
instrument consisted of six cylindrical elements 11 m long and 28 mm in
diameter. Each antenna was insulated from the plasma except for the outer 2 m.
The baseline, or distance between the midpoints of these 2-m active elements,
was 20 m. The antennas were interlocked along the edges to prevent oscillation
and to increase their rigidity against drag forces. The basic electronic system
was very similar in concept to those used on IMP-J and ISEE 1, but modified for
a three-axis measurement on a nonspinning spacecraft. At the core of the system
were the high-impedance (1.E12 ohm) preamplifiers, whose outputs were accurately
subtracted and digitized (14-bit A/D conversion for sensitivity to about 0.1
microvolt/m) to maintain high resolution, for subsequent removal of the
cross-product of the vectors V and B in data processing. This provided the basic
dc measurement. Other circuitry was used to aid in interpreting the dc data and
to measure rapid variations in the signals detected by the antennas. The planned
dc electric field range was plus or minus 1 V/m, the planned resolution was 0.1
mV/m, and the variational electric field was measured from 4 Hz to 1024 Hz.  The
dc electric field was measured at 16 samples/s.  The variational electric field
was measured from 1 microvolt/m to 10 mV/m rms. Additional details are found in
N. C. Maynard et al., Space Sci. Instrum., v. 5, n. 4, p. 523, 1981. The antenna
pair perpendicular to the orbit plane did not deploy.

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DE2_DCA500MS_VEFI doi:10.48322/0s61-a111

Description

The Vector Electric Field Instrument (VEFI) used flight-proven double-probe
techniques with 20-m baselines to obtain measurements of dc electric fields.
This electric field investigation had the following objectives: (1) to obtain
accurate and comprehensive triaxial dc electric field measurements at
ionospheric altitudes in order to refine the basic spatial patterns, define the
large-scale time history of these patterns, and study the small-scale temporal
and spatial variations within the overall patterns; (2) to study the degree to
which and in what region the electric field projects to the equatorial plane;
(3) to obtain measurements of extreme low frequency (ELF) and lower frequency
irregularity structures; and (4) to perform numerous correlative studies. The
instrument consisted of six cylindrical elements 11 m long and 28 mm in
diameter. Each antenna was insulated from the plasma except for the outer 2 m.
The baseline, or distance between the midpoints of these 2-m active elements,
was 20 m. The antennas were interlocked along the edges to prevent oscillation
and to increase their rigidity against drag forces. The basic electronic system
was very similar in concept to those used on IMP-J and ISEE 1, but modified for
a three-axis measurement on a nonspinning spacecraft. At the core of the system
were the high-impedance (1.E12 ohm) preamplifiers, whose outputs were accurately
subtracted and digitized (14-bit A/D conversion for sensitivity to about 0.1
microvolt/m) to maintain high resolution, for subsequent removal of the
cross-product of the vectors V and B in data processing. This provided the basic
dc measurement. Other circuitry was used to aid in interpreting the dc data and
to measure rapid variations in the signals detected by the antennas. The planned
dc electric field range was plus or minus 1 V/m, the planned resolution was 0.1
mV/m, and the variational electric field was measured from 4 Hz to 1024 Hz.  The
dc electric field was measured at 16 samples/s.  The variational electric field
was measured from 1 microvolt/m to 10 mV/m rms. Additional details are found in
N. C. Maynard et al., Space Sci. Instrum., v. 5, n. 4, p. 523, 1981. The antenna
pair perpendicular to the orbit plane did not deploy.

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DE2_DUCT16MS_RPA doi:10.48322/aab6-jj49

Description

The Retarding Potential Analyzer (RPA) measured the bulk ion velocity in the
direction of the spacecraft motion, the constituent ion concentrations, and the
ion temperature along the satellite path. These parameters were derived from a
least squares fit to the ion number flux vs energy curve obtained by sweeping or
stepping the voltage applied to the internal retarding grids of the RPA. In
addition, a separate wide aperture sensor, a duct sensor, was flown to measure
the spectral characteristics of iregularities in the total ion concentration.
The measured parameters obtained from this investigation were important to the
understanding of mechanisms that influence the plasma; i.e., to understand the
coupling between the solar wind and the earth's atmosphere. The measurements
were made with a multigridded planar retarding potential analyzer very similar
in concept and geometry to the instruments carried on the AE satellites. The
retarding potential was variable in the range from approximately +32 to 0 volts.
The details of this voltage trace, and whether it was continuous or stepped,
depended on the operating mode of the instrument. Specific parameters deduced
from these measurements were ion temperature; vehicle potential; ram component
of the ion drift velocity; the ion and electron concentration irregularity
spectrum; and the concentration of H+, He+, O+, and Fe+, and of molecular ions
near perigee. Additional details are in W. B. Hanson et al., Space Sci.
Instrum., v. 5, n. 4, p. 503, 1981.
It includes the DUCT portion of the high resolutiondata from the Dynamics
Explorer 2 (DE-2) Retarding Potential Analyzer (RPA) for the whole DE-2 mission
time period in ASCII format. This version was generated at NSSDC from the
PI-provided binary data (SPIO-00232). The DUCT files include RPA measurements of
the total ion concentration every 64 times per second. Due to a failure in the
instrument memory system RPA data are not available from 81317 06:26:40 UT to
82057 13:16:00 UT. This data set is based on the revised version of the RPA
files that was submitted by the PI team in June of 1995. The revised RPA data
include a correction to the spacecraft potential.

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DE2_ION2S_RPA doi:10.48322/41b3-kz41

Description

The Retarding Potential Analyzer (RPA) measured the bulk ion velocity in the
direction of the spacecraft motion, the constituent ion concentrations, and the
ion temperature along the satellite path. These parameters were derived from a
least squares fit to the ion number flux vs energy curve obtained by sweeping or
stepping the voltage applied to the internal retarding grids of the RPA. In
addition, a separate wide aperture sensor, a duct sensor, was flown to measure
the spectral characteristics of iregularities in the total ion concentration.
The measured parameters obtained from this investigation were important to the
understanding of mechanisms that influence the plasma; i.e., to understand the
coupling between the solar wind and the earth's atmosphere. The measurements
were made with a multigridded planar retarding potential analyzer very similar
in concept and geometry to the instruments carried on the AE satellites. The
retarding potential was variable in the range from approximately +32 to 0 volts.
The details of this voltage trace, and whether it was continuous or stepped,
depended on the operating mode of the instrument. Specific parameters deduced
from these measurements were ion temperature; vehicle potential; ram component
of the ion drift velocity; the ion and electron concentration irregularity
spectrum; and the concentration of H+, He+, O+, and Fe+, and of molecular ions
near perigee. Additional details are in W. B. Hanson et al., Space Sci.
Instrum., v. 5, n. 4, p. 503, 1981.
It includes the high-resolution data from the Dynamics Explorer 2 (DE-2)
Retarding Potential Analyzer (RPA) for the whole DE-2 mission time period in
ASCII format.  The ASCII version was generated at NSSDC from the PI-provided
binary data (SPIO-00232). The RPA data files include orbit parameters and
geophysical data at a time resolution of usually 2 seconds and sometimes 4
second. The following geophysical parameters are provided: ion drift vector, ion
density, ion temperature, spacecraft potential, ion densities of atomic oxygen,
hydrogen, helium, molecular constituents and high mass constituents, data
quality flag, and RMS error. The ion drift vector is given by its components in
spacecraft coordinates; the y and z components are IDM measurements. Due to a
failure in the instrument memory system RPA data are not available from 81317
06:26:40 UT to 82057 13:16:00 UT. This data set is based on the revised version
of the RPA files that was submitted by the PI team in June of 1995. The revised
RPA data include a correction to the spacecraft potential.
The Dynamics Explorer 2 Retarding Potential Analyzer (RPA) files contain the ion
temperature, the ion drift velocity along the sensor look direction, and the ion
composition and orbit parameters in ASCII format. The time resolution is
typically 2 seconds. Data are given as daily files (typically a few 100 Kbytes
each). NSSDC-developed software was used to read the RPA binary data and create
ASCII files.  For more on DE-2, RPA, and the binary data, see RPA_VOLDESC_DE.SFD
and RPA_FORMAT_DE.SFD. 
The RPA files are requested with the DATA_TYPE = RPA_ASCII and the ENTRY_ID =
yyddd and are then staged as yydddhhmm_RPA_DE_2S_V01.ASC; yy is the year, ddd is
the day of the year, hh is the hour, and mm is the minute of the starting time
of the data in the file.  The date range for the IDM files is 81218-83049 with
most days represented.
The data quality field contains a flag that describes the quality of the RPA
data.  A value greater than or equal to 0 indicates that the data has passed the
set of basic quality checks.  A negative value indicates that the RPA data fails
at least one check and is untrustworthy.  Following are the sequence of checks.
Tests are sequentially performed until a flag is assigned. 
   Ni<8000 or Ni>6.E6                 flag=-70
   Psi<-2 or Psi>0.5                  flag=-60
   for INVARIANT LATITUDE<50
      Ti<500 or Ti>10000              flag=-50
      |Vx|>700 m/s                    flag=-20
      Mols>O+                         flag=-40
       H+>O+                          flag=-30
       Vx=0                           flag= 40
       Vx non zero 
         Sum of light ions > 25% O+   flag= 50
         Sum of light ions < 25% O+   flag= 20
   set flag to 0 if one of the needed concentrations is unavailable.
   increase magnitude of flag by 5 if rms fit error > 10%
   for INVARIANT LATITUDE>50
      Ti<500 or Ti>200000             flag=-50
        Ti>7000
          |Vx|<1000 and |Vz|<1000     flag=-20
          Alt>600
            Mols>O+                   flag=-40
            O+>Mols                   flag= 30
          Alt<=600
           Mols>O+
             Vx>0                     flag=-10
             Vx<=0                    flag=  0
           O+>Mols                    flag= 30
        Ti<=7000
          |Vx|>2000                   flag=-20
          Mols>O+                     flag=-40
          O+>Mols                     flag= 60
   set flag to 0 if one of the needed concentrations is unavailable. Increase
magnitude of flag by 5 if rms fit error > 12%
The sweep type field contains a number (1 - 4) that represents the type of RPA
sweep used.  The sweep types are: 
  1. Integral RPA curve obtained with voltage sweep from 0 to beyond 10 volts.
  2. Electronic derivative of RPA curve obtained with voltage sweep from 0 to
beyond 10 volts.
  3. Integral RPA curve obtained with voltage sweep from 0 up to 8 volts.
  4. Electronic derivative of RPA curve obtained with voltage sweep from 0 to 8
volts.

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DE2_LAPI_ELECTRON-FLUX-COUNTS-PPS1

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

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DE2_LAPI_ELECTRON-FLUX-COUNTS-PPS2

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

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DE2_LAPI_GEIGER-MUELLER

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

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DE2_LAPI_GEIGER-MUELLER-RATIO

Description

The Low Altitude Plasma Instrument /LAPI/ The Low Altitude Plasma Instrument on
the Dynamics Explorer-B spacecraft provides high resolution velocity space
measurements of positive ions and electrons from 5 eV to 32 keV and a monitor of
electrons with energies above 35 keV. It consists of an array of 15 parabolic
electrostatic analyzers spanning 180 deg in angle and two Geiger-Mueller
counters mounted on a one-degree of freedom-scan platform. The platform is
controlled by a magnetometer that allows placement of the array to selected
angles with respect to the magnetic field. Each parabolic analyzer
simultaneously measures electrons and positive ions. The temporal resolution and
energy range of the measurements and the detector complement to be sampled are
programmable by ground command. 
1. The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
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DE2_LAPI_ION-FLUX-COUNTS-PPS1

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
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DE2_LAPI_ION-FLUX-COUNTS-PPS2

Description

The Low Altitude Plasma Instrument /LAPI/ The Low Altitude Plasma Instrument on
the Dynamics Explorer-B spacecraft provides high resolution velocity space
measurements of positive ions and electrons from 5 eV to 32 keV and a monitor of
electrons with energies above 35 keV. It consists of an array of 15 parabolic
electrostatic analyzers spanning 180 deg in angle and two Geiger-Mueller
counters mounted on a one-degree of freedom-scan platform. The platform is
controlled by a magnetometer that allows placement of the array to selected
angles with respect to the magnetic field. Each parabolic analyzer
simultaneously measures electrons and positive ions. The temporal resolution and
energy range of the measurements and the detector complement to be sampled are
programmable by ground command. 
1. The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
Data Access Code Examples written in

and IDL®.
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DE2_LAPI_LAPI-MAG

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
Data Access Code Examples written in

and IDL®.
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DE2_LAPI_ORBIT-ATTITUDE

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
Data Access Code Examples written in

and IDL®.
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DE2_LAPI_ORBIT-ATTITUDE-MAGB

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
Data Access Code Examples written in

and IDL®.
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DE2_LAPI_PITCH-ANGLES

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
Data Access Code Examples written in

and IDL®.
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DE2_LAPI_PROJECTED-MAGB

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
Instruments abbreviations: 
FPI: Fabry-Perot Interferometer
IDM: Ion Drift Meter
LANG: Langmuir Probe
LAPI: Low Altitude Plasma Instrument
MAG-B: Magnetic Field Observations Triaxial Fluxgate Magnetometer
NACS: Neutral Atmosphere Composition Spectrometer
VEFI: Vector Electric Field Instrument
WATS: Wind and Temperature Spectrometer
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
Data Access Code Examples written in

and IDL®.
Back to top

DE2_LAPI_SC-MAGB

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
Instruments abbreviations: 
FPI: Fabry-Perot Interferometer
IDM: Ion Drift Meter
LANG: Langmuir Probe
LAPI: Low Altitude Plasma Instrument
MAG-B: Magnetic Field Observations Triaxial Fluxgate Magnetometer
NACS: Neutral Atmosphere Composition Spectrometer
VEFI: Vector Electric Field Instrument
WATS: Wind and Temperature Spectrometer
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

Data Variable Descriptions

Dataset in CDAWeb
Data Access Code Examples written in

and IDL®.
Back to top

DE2_LAPI_SHAFT-ENCODER-ANGLE

Description

The DE-2 spacecraft (low-altitude mission) complemented the high-altitude
mission DE-1and was placed into an orbit with a perigee sufficiently low to
permit measurements of neutral composition, temperature, and wind. The apogee
was high enough to permit measurements above the interaction regions of
suprathermal ions, and also plasma flow measurements at the feet of the
magnetospheric field lines. The general form of the spacecraft was a short
polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m
tip-to-tip. One 6-m boom was provided for remote measurements. The spacecraft
weight was 403 kg. Power was supplied by a solar cell array, which charged two
6-ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized
with the yaw axis aligned toward the center of the earth to within 1 deg. The
spin axis was normal to the orbit plane within 1 deg with a spin rate of one
revolution per orbit. A single-axis scan platform was included in order to mount
the low-altitude plasma instrument (81-070B-08). The platform rotated about the
spin axis. A pulse code modulation telemetry data system was used that operated
in real time or in a tape-recorder mode. Data were acquired on a
science-problem-oriented basis, with closely coordinated operations of the
various instruments, both satellites, and supportive experiments. Measurements
were temporarily stored on tape recorders before transmission at an 8:1
playback-to-record ratio. Since commands were also stored in a command memory
unit, spacecraft operations were not real time. Additional details can be found
in R. A. Hoffman et al., Space Sci. Instrum., v. 5, n. 4, p. 349, 1981. DE-2
reentered the atmosphere on February 19, 1983. 
The Low-Altitude Plasma Instrument (LAPI) provided high-resolution velocity
space measurements of positive ions and electrons from 5 eV to 32 keV. The two
Geiger-Mueller counter tubes (0 and 90 deg) measured trapped electrons and
precipitating electrons above 35 keV as integral number flux. Pitch angle
measurements covered the full 180 deg range. Data from this investigation and
supporting measurements were used to study 
(1) the identification and intensities of Birkeland currents, 
(2) auroral particle source regions and acceleration mechanisms, 
(3) the existence and role of E parallel to B, 
(4) sources and effects of polar cap particle fluxes, 
(5) the transport of plasma within and through the magnetospheric cusp, 
(6) dynamic configurations of high-latitude flux tubes, 
(7) loss-cone effects of wave-particle interactions, 
(8) hot-cold plasma interactions, 
(9) ionospheric effects of particle precipitation, and 
(10) plasma convection at high altitudes. 
The instrument contained an array of 15 parabolic electrostatic analyzers of the
ISIS 2 type, each with an electron channel and an ion channel, in order to
obtain detailed pitch-angle distributions as a function of energy. Two
Geiger-Mueller counters were mounted on the scan platform. The basic mode of
operation provided a 32-point energy spectrum in the range 5 eV to 32 kev every
second. The voltages on the electrostatic analyzers were programmable to allow
for greater space/time resolution over limited portions of the energy and
angular distributions. The instrument was mounted on a one-axis scan platform
controlled by a magnetometer, whose purpose was to maintain the detector array,
which spanned 180 deg, at a nearly constant angle to the magnetic field.
Additional details are found in J. D. Winningham et al., Space Sci. Instrum., v.
5, n. 4, p. 465, 1981. From March 16, 1982 to April 4, 1982 the instrument was
turned off for corrective action. 
The Instrument Data File Set. URL http://www.idfs.org

Modification History

Initial Release

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DE2_NEUTRAL1S_NACS doi:10.48322/j8kp-5y58

Description

The Neutral Atmosphere Composition Spectrometer (NACS) was designed to obtain in
situ measurements of the neutral atmospheric composition and to study the
variations of the neutral atmosphere in response to energy coupled into it from
the magnetosphere.  Because temperature enhancements, large-scale circulation
cells, and wave propagation are produced by energy input (each of which posseses
a specific signature in composition variation), the measurements permitted the
study of the partition, flow, and deposition of energy from the magnetosphere. 
Specifically, the investigation objective was to characterize the composition of
the neutral atmosphere with particular emphasis on variability in constituent
densities driven by interactions in the atmosphere, ionosphere, and
magnetosphere system. The quadrupole mass spectrometer used was nearly identical
to those flown on the AE-C, -D, and -E missions. The electron-impact ion source
was used in a closed mode. Atmospheric particles entered an antechamber through
a knife-edged orifice, where they were thermalized to the instrument
temperature. The ions with the selected charge-to-mass ratios had stable
trajectories through the hyperbolic electric field, exited the analyzer, and
entered the detection system. An off-axis beryllium-copper dynode multiplier
operating at a gain of 2.E6 provided an output pulse of electrons for each ion
arrival. The detector output had a pulse rate proportional to the neutral
density in the ion source of the selected mass. The instrument also included two
baffles that scanned across the input orifice for optional measurement of the
zonal and vertical components of the neutral wind. The mass select system
provided for 256 mass values between 0 and 51 atomic mass units (u) or each 0.2
u. It was possible to call any one of these mass numbers into each of eight
0.016-s intervals. This sequence was repeated each 0.128 s. More details are
found in G. R. Carignan et al., Space Sci. Instrum., v. 5, n. 4, p. 429, 1981.
This data set includes daily files of the PI-provided DE-2 NACS 1-second data
and corresponding orbit parameters.  The data set was generated at NSSDC from
the original PI-provided data and software (SPTH-00010) and from the
orbit/attitude database and software that is part of the DE-2 UA data set
(SPIO-00174). The original NACS data were provided by the PI team in a highly
compressed VAX/VMS binary format on magnetic tapes. The data set covers the
whole DE-2 mission time period. Each data point is an average over the normally
8 measurements per second. Densities and relative errors are provided for atomic
oxygen (O), molecular nitrogen (N2), helium (He), atomic nitrogen (N), and argon
(Ar).  The data quality is generally quite good below 500 km, but deteriorates
towards higher altitudes as oxygen and molecular nitrogen approach their
background values (which could only be determined from infrequent spinning
orbits) and the count rate for Ar becomes very low. The difference between
minimum (background) and maximum count rate for atomic nitrogen (estimated from
mass 30) was so small that results are generally poor.  Data were lost between
12 March 1982 and 31 March 1982 when the counter overflowed.

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DE2_NEUTRAL8S_FPI doi:10.48322/22v6-0p09

Description

The Fabry-Perot Interferometer (FPI) was a high-resolution remote sensing
instrument designed to measure the thermospheric temperature, meridional wind,
and density of the following metastable atoms: atomic oxygen (singlet S and D)
and the 2P state of ionic atomic oxygen. The FPI performed a wavelength analysis
on the light detected from the thermospheric emission features by spatially
scanning the interference fringe plane with a multichannel array detector. The
wavelength analysis characterized the Doppler line profile of the emitting
species. A sequential altitude scan performed by a commandable horizon scan
mirror provided a cross-sectional view of the thermodynamic and dynamic state of
the thermosphere below the DE 2 orbit. The information obtained from this
investigation was used to study the dynamic response of the thermosphere to the
energy sources caused by magnetospheric electric fields and the absorption of
solar ultraviolet light in the thermosphere. The instrument was based on the
visible airglow experiment (VAE) used in the AE program. The addition of a
scanning mirror, the Fabry-Perot etalon, an image plane detector, and a
calibration lamp were the principal differences. Interference filters isolated
lines at (in Angstroms) 5577, 6300, 7320, 5896, and 5200. The FPI had a field of
view of 0.53 deg (half-cone angle). More details are found in P. B. Hays et al.,
Space Sci. Instrum., v. 5, n. 4, p. 395, 1981. From February 16, 1982 to
September 11, 1982 the DE satellite was inverted and the FPI measured galactic
emissions.
NOTE: Animations of DE2-FPI science products have been created as daily summary
files. The animations contain binned averages displayed as a colour code against
a geographic background. The bin sizes are 7.5 deg latitude and 24.0 degree
longitude. The longitude bin corresponds to the approximate separation of
adjacent orbits, assuming that DE2 completed 15 orbits per day. The animations
are divided into day (06-18 LST) and night (18-06 LST). All summary file
information and animations employ spacecraft orbital attitude data. Users should
note 1) that the DE2-FPI experiment acquired airglow spectra by imaging the
terrestrial limb below and ahead of the spacecraft at an approximate tangent
altitude of 250 km; 2) all airglow spectra were acquired while the DE2
spacecraft orbited in it's normal configuration, which corresponded to calendar
months August to February in 1981/2 and 1982/3; 3) the orbital inclination of
DE2 was 90 degrees implying that DE2-FPI always viewed ahead along the meridian;
4) that DE2 flew in an elliptical orbit with perigee of 305 km and apogee of
1300 km at launch -- the altitude of DE2 for each FPI measurement is included
with each reduced data point permitting users to determine the tangent latitude
corresponding to the 250 km terrestrial airglow limb. The three gif animations
are: 
1. FPI_brightness.gif which documents the OI (6300A) column brightness in units
of log10 Rayleighs. Note different scales for day and night.
2. FPI_temperature.gif which documents the neutral thermosphere temperature in
units of degrees Kelvin.
3. FPI_wind.gif which documents the line of sight neutral wind component in
units of meters/second. The wind direction is positive when the wind blows away
from the approaching spacecraft.

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DE2_PLASMA500MS_LANG doi:10.48322/yq6h-5g10

Description

The Langmuir Probe Instrument (LANG) was a cylindrical electrostatic probe that
obtained measurements of electron temperature, Te, and electron or ion
concentration, Ne or Ni, respectively, and spacecraft potential.  Data from this
investigation were used to provide temperature and density measurements along
magnetic field lines related to thermal energy and particle flows within the
magnetosphere-ionosphere system, to provide thermal plasma conditions for
wave-particle interactions, and to measure large-scale and fine-structure
ionospheric effects of energy deposition in the ionosphere.  The Langmuir Probe
instrument was identical to that used on the AE satellites and the Pioneer Venus
Orbiter. Two independent sensors were connected to individual adaptive sweep
voltage circuits which continuously tracked the changing electron temperature
and spacecraft potential, while autoranging electrometers adjusted their gain in
response to the changing plasma density. The control signals used to achieve
this automatic tracking provided a continuous monitor of the ionospheric
parameters without telemetering each volt-ampere (V-I) curve.  Furthermore,
internal data storage circuits permitted high resolution, high data rate
sampling of selected V-I curves for transmission to ground to verify or correct
the inflight processed data. Time resolution was 0.5 seconds. More details are
in J. P. Krehbiel et al., Space Sci. Instrum., v. 5, n. 4, p. 493, 1981.
The Dynamics Explorer 2 Langmuir Probe (LANG) ASCII files contain the following
geophysical parameters: electron temperature, plasma density, and satellite
potential.  They also contain the most important DE-2 orbit parameters.  The
geophysical parameters in the ASCII files were derived.from the raw volt-ampere
data from LANG.  PI-provided software was used to convert the raw binary data
into the ASCII geophysical data.

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DE2_UA16S_ALL doi:10.48322/1w0s-2q42

Description

This data set was generated at NSSDC from the DE-2 Unified Abstract (UA) data
and the DE-2 orbit/attitude data base and software. The daily UA files contain
16 second averages from the NACS, WATS, LANG, FPI and RPA/IDM instruments for
the whole DE-2 mission period.  The PI-provided data in VAX/VMS binary format
were converted to ASCII format and the most important orbit parameters were
added using the a/o data base and software provided by the DE project team.
Subsetting, plotting, and downloading (in ASCII format) capabilities for these
data are provided through the ATMOWeb interface at
https://nssdc.gsfc.nasa.gov/atmoweb/The ASCII are are also available from here:
https://spdf.gsfc.nasa.gov/pub/data/de/de2/ Each UA record contains the
following data: N2, O, He, Ar, and N densities [cm-3] from the Neutral
Atmosphere Composition Spectrometer (NACS), neutral temperature [K], eastward
and upward neutral wind [m/s] from the Wind and Temperature Spectrometer (WATS),
plasma density [cm-3] and electron temperature [K] from the Langmuir Probe
experiment (LANG), wavelength [A], tangent altitude [km], northward neutral wind
[m/s], neutral temperature [K], and intensity [Raleighs], from the Fabry
Interferometer (FPI), ion temperature [K], total ion density [cm-3], eastward,
northward, and upward ion drift [m/s] from the Retarding Potential Analyzer/Ion
Drift Meter (RPA/IDM). The IDM data entry is the revised version of June 1994.
Also included are the latitude, longitude, altitude, local time and other orbit
parameters. Higher time resolution data are available from NSSDC for the
individual experiments at https://spdf.gsfc.nasa.gov/pub/data/de/de2/ 
This investigation used data from several spacecraft instruments to study the
large-scale neutral-plasma interactions in the thermosphere caused by
magnetospheric-ionospheric and thermospheric coupling processes. Planned use of
the models is to provide a theoretical framework in which certain important
ionospheric and atmospheric properties needed for coupling processes (such as
the Pedersen and Hall conductivities) were consistently calculated using
satellite data measured at a given height. Planned examples are (1) to calculate
vertical profiles of ionospheric properties that were useful for comparison with
incoherent scatter radar measurements and other ground-based supporting data,
(2) to identify and evaluate the neutral thermospheric heat and momentum
sources, and (3) to determine the effectiveness of high-latitude dynamic
processes in controlling the global thermospheric circulation and thermal
structure.

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DE2_VION250MS_IDM doi:10.48322/reef-jt02

Description

The Ion Drift Meter (IDM) measured the bulk motions of the ionospheric plasma
perpendicular to the satellite velocity vector. The measured parameters,
horizontal and vertical ion-drift velocities, had an expected range of plus or
minus 4 km/s. The accuracy of the measurement was expected to be plus or minus
50 m/s for the anticipated 0.5 deg accuracy in vehicle attitude determination.
The nominal time resolution of the measurement was 1/32 s. This investigation
yielded information on (1) the ion convection (electric field) pattern in the
auroral and polar ionosphere; (2) the flow of plasma along magnetic field lines
within the plasmasphere, which determines whether this motion was simply a
breathing of the protonosphere, a refilling of this region after a storm, or an
interhemispheric transport of plasma; (3) the thermal ion contribution to
field-aligned electric currents; (4) velocity fields associated with small-scale
phenomena that are important at both low and high latitudes; and (5) the
magnitude and variation of the total concentration along the flight path. The
ion drift meter measured the plasma motion parallel to the sensor face by using
a gridded collimator and multiple collectors to determine the direction of
arrival of the plasma. The instrument geometry was very similar to that used on
the Atmosphere Explorer satellites. Each sensor consisted of a square entrance
aperture that served as collimator, some electrically isolating grids, and a
segmented planar collector. The angle of arrival of the ions with respect to the
sensor was determined by measuring the ratio of the currents to the different
collector segments, and this was done by taking the difference in the logarithms
of the current. Two techniques were used to determine this ratio. In the
standard drift sensor (SDS), the collector segments were connected in pairs to
two logarithmic amplifiers. The second technique, called the univeral drift
sensor (UDS), allowed simultaneous measurement of both components. Here, each
collector segment was permanently connected to a logarithmic amplifier and two
difference amplifiers were used to determine the horizontal and vertical arrival
angles simultaneously. The IDM consisted of two sensors, one providing the SDS
output and the other providing the UDS output. Further details are in R. A.
Heelis et al., Space Sci. Instrum., v. 5, n. 4, p. 511, 1981. During the period
from 81317 to 82057 the instrument memory suffered a critical upset and ion
temperatures and drifts are not available during this period.
This data set is available from here:
https://spdf.gsfc.nasa.gov/pub/data/de/de2/ It includes the high-resolution data
from the Dynamics Explorer 2 (DE-2) Ion Drift Meter (IDM) for the whole DE-2
mission time period in ASCII format. This data set was generated at NSSDC by
converting the PI-provided data set (SPIO-00232) from binary to ASCII format.
The IDM data files provide absolute measurements of the cross track ion drift
velocity 4 times per second. The complete drift vector can be obtained by
combining IDM and RPA ion drift measurements.

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DE2_WIND2S_WATS doi:10.48322/z50y-hd65

Description

The Wind and Temperature Spectrometer (WATS) measured the in situ neutral winds,
the neutral particle temperatures, and the concentrations of selected gases. The
objective of this investigation was to study the interrelationships among the
winds, temperatures, plasma drift, electric fields, and other properties of the
thermosphere that were measured by this and other instruments on the spacecraft.
Knowledge of how these properties are interrelated contributed to an
understanding of the consequences of the acceleration of neutral particles by
the ions in the ionosphere, the acceleration of ions by neutrals creating
electric fields, and the related energy transfer between the ionosphere and the
magnetosphere. Three components of the wind, one normal to the satellite
velocity vector in the horizontal plane, one vertical, and one in the satellite
direction were measured. A retarding potential quadrupole mass spectrometer,
coupled to the atmosphere through a precisely orificed antechamber, was used. It
was operated in either of two modes: one employed the retarding capability and
the other used the ion source as a conventional nonretarding source. Two
scanning baffles were used in front of the mass spectrometer: one moved
vertically and the other moved horizontally. The magnitudes of the horizontal
and vertical components of the wind normal to the spacecraft velocity vector
were computed from measurements of the angular relationship between the neutral
particle stream and the sensor. The component of the total stream velocity in
the satellite direction was measured directly by the spectrometer system through
determination of the required retarding potential.  At altitudes too high for
neutral species measurements, the planned operation required the instrument to
measure the thermal ion species only.  A series of four sequentially occurring
slots --each a 2-s long measurement interval-- was adapted for the basic
measurement format of the instrument. Different functions were commanded into
these slots in any combination, one per measurement interval. Thus the time
resolution can be 2, 4, 6, or 8 seconds.  Further details are found in N. W.
Spencer et al., Space Sci. Instrum., v. 5, n. 4, p. 417, 1981.
This data set consists of the high-resolution data of the Dynamics .Explorer 2
Wind and Temperature Spectrometer (WATS) experiment. The files contain the
neutral density, temperature and horizontal (zonal) wind velocity, and orbital
parameters in ASCII format. The time resolution is typically 2 seconds. Data are
given as daily files (typically a few 100 Kbytes each). PI-provided software
(WATSCOR) was used to correct the binary data set.  NSSDC-developed software was
used to add the orbit parameters, to convert the binary into ASCII format and to
combine the (PI-provided) orbital files into daily files. For more on DE-2,
WATS, and the binary data, see the WATS_VOLDESC_SFDU_DE.DOC and
WATS_FORMAT_SFDU_DE.DOC files. More information about the processing done at
NSSDC is given in WATS_NSSDC_PRO_DE.DOC.

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DE_UV_SAI doi:10.48322/t7ya-6231

Description

   Instrument functional description:
       The spin-scan auroral imagers (SAI) comprise three photometers which
   provide images of Earth at various wavelengths via interference filters
   mounted on a wheel and selected by ground command.  Two of the photometers
   provide visible wavelength images, and the third provides images at
   vacuum-ultraviolet wavelengths.
       The three photometers are mounted on the spacecraft such that their
   fields of view are separated by about 120 degrees in a plane oriented
   perpendicular to the spin axis.  Each photometer in operation collects
   one scan line during each spacecraft rotation, with an internal mirror
   stepping once per rotation to start a new scan line.
       An auroral image is a nadir-centered two-dimensional pixel array
   provided by the spacecraft rotation and the photometer's stepping mirror
   which advances the field of view 0.25 degrees once per rotation in a
   direction perpendicular to the plane of rotation.  A change in mirror-
   stepping direction signals the start of a new image.  One, two, or
   three photometers may be in operation at one time.  The images from all
   operating photometers are telemetered simultaneously with image repetition
   rates that typically vary from about 3 to 12 minutes.
       One of the three imaging photometers is equipped with filters and a
   photocathode for observations at vacuum-ultraviolet wavelengths, in
   particular emissions of the Lyman-Birge-Hopfield band of molecular
   nitrogen at about 140 to 170 nm.  Imaging at these wavelengths allows
   coverage of the auroral oval in both the dark and sunlit ionospheres.
   The filter array for the vacuum-ultraviolet imaging photometer also
   includes filters for atomic hydrogen Lyman alpha at 121.6 nm and oxygen
   lines at 130.4 and 135.6 nm.
       The full width of the fields of view of the photometers
   corresponding to a single pixel is 0.29 degrees.  An image frame
   consists of all scan lines obtained by mirror steps in one direction
   which deflect the field of view by 0.25 degrees per rotation.  The
   angular separation of two consecutive pixels in the direction of
   spacecraft rotation is about 0.23 degrees.  A full frame has 120
   scan lines or 30 degrees of width.  For routine processing the
   angular width along a scan line is 150 pixels, or about 34.5 degrees
   of length.  The frame width is occasionally adjusted to less than
   120 scan lines.
   Reference:
   Frank, L. A., J. D. Craven, K. L. Ackerson, M. R. English, R. H. Eather,
       and R. L. Carovillano, Global auroral imaging instrumentation for
       the Dynamics Explorer mission, Space Sci. Inst., 5, 369-393, 1981.
   Data set description:
       Each DE SAI UV image CDF contains all of images collected by the
   UV photometer during one day of operations.  The displayable image
   counts are in variable 3.
       Coordinates are calculated for each position of the image count array.
   These coordinates are in variables 14, 15, and 16.
       To facilitate viewing of the images, a mapping of pixel value to a
   recommended color table based on the characteristics of the selected
   filter will be included with each image.  See the description of variables
   17, 18, and 19 below.
       A relative intensity scale is provided by the uncompressed count
   table of variable 20.  Approximate intensity levels in kiloRayleighs are
   given in the intensity table of variable 21.
       Other variables provide orbit and attitude data and information about
   the selected filter and the mirror stepping direction.
 Variable descriptions:
  1,2. Start time
        The time assigned to an image is the start time of the initial scan
        line within a resolution of one second.
    3. Image counts
        Image pixel counts range from 0 to 255.  They are stored in a two-
        dimensional byte array of 121 columns by 150 rows.  Each column
        contains one scan line.  Images will generally not fill all of the
        121 columns.  When an image is displayed with row 1 at the top and
        column 1 on the left, the spacecraft spin axis is oriented to the
        left in the display, and the orbit normal vector is oriented to the
        right.
    4. Filter
        Twelve filters are available for ultra-violet imaging; the filter
        number, 1-12, is given here.  In addition, the peak wavelength in
        Angstroms is given for the selected filter.
    5. Presumed altitude of emissions
        The presumed altitude of the emissions seen in the image varies
        with the characteristics of the filter used.
  6,7. First and last mirror location counters (MLCs)
        The MLC range is from 28 in column 1 (leftmost) to 148 in column 121
        (rightmost).  The direction of mirror stepping motion is shown by
        comparing first and last MLCs.
    8. Orbit/attitude time
        Whenever possible, the approximate center time of the image is used
        for determining the orbit and attitude parameters.  If O/A data is
        not available for the center time, the closest available O/A time
        is used.
    9. Spacecraft position vector, GCI
   10. Spacecraft velocity vector, GCI
   11. Spacecraft spin axis unit vector, GCI
   12. Sun position unit vector, GCI
   13. Orbit normal unit vector, GCI
   14. Geographic longitude or right ascension
        East longitude is given for each image pixel on the Earth at the
        altitude given in variable 5.  When the pixel altitude is greater
        than the value of variable 5, the right ascension is given.
   15. Geographic latitude or declination
        North latitude is given for each image pixel on the Earth at the
        altitude given in variable 5.  When the pixel altitude is greater
        than the value of variable 5, the declination is given.
   16. Pixel altitude
        For each image pixel on the Earth, the presumed altitude of the
        emissions is used.  This is equal to the value of variable 5.  For each
        pixel off the Earth, the altitude of the line of sight is used.
   17. Pixel UT
        This array gives the start time for the collection of each image pixel.
   18. RGB color table
        This is the recommended color table to be used with the
        limits given in variables 19 and 20.
19,20. Low and high color mapping limits
        The low and high color limits are recommended for remapping
        the color table entries, as follows:
            For pixel values less than the low limit, use the color
                at table position 1.
            For pixel values greater than or equal to the low limit
                and less than or equal to the high limit, use the color
                at table position (pix-low)/(high-low) x 255 + 1.
            For pixel values greater than the high limit, use the color
                at table position 256.
   21. Expanded count table
        The image pixel counts are quasi-logarithmically compressed to the
        range 0-255.  This table gives the average of the uncompressed range
        for each compressed count value.  Table entries 1-128 correspond to
        compressed counts 0-127 respectively.  Count levels greater than
        127 are considered overflow.
   22. Intensity table
        For each of the twelve filters, approximate intensity levels in
        kiloRayleighs are given for each compressed count value.  Table
        entries 1-128 correspond to compressed counts 0-127 respectively.
        No count conversion data is available for count levels greater than
        127.
   Supporting software:
         Directions for obtaining supporting software is available on the SAI
   website at the URL .http://www-pi.physics.uiowa.edu/www/desai/software/. 
   Included is an IDL program that displays the images with the recommended
   color bar and provides approximate intensities and coordinate data for
   each pixel.

Data Variable Descriptions

Ultraviolet Image (quasi-logarithmically compressed counts) [Image_Counts]

Image_Counts contains the displayable image in 121 columns by 150 rows of
pixels.  Most images will use 120 of the columns.  The counts have been
quasi-logarithmically compressed by the instrument.  Approximate uncompressed
value for Image_Counts(i,j) is ExpandedCount(Image_Counts(i,j)+1).  Approximate
intensity in kR is Intens_Table(Image_Counts(i,j)+1).The appearance of the
actual count value 255 is rare.  When displaying an image,it works best to use
the fill value as an overflow (i.e. brightest) value.

--> Ultraviolet Mapped Image (quasi-logarithmically compressed counts) [Image_CountsM]

Image_Counts contains the displayable image in 121 columns by 150 rows of
pixels.  Most images will use 120 of the columns.  The counts have been
quasi-logarithmically compressed by the instrument.  Approximate uncompressed
value for Image_Counts(i,j) is ExpandedCount(Image_Counts(i,j)+1).  Approximate
intensity in kR is Intens_Table(Image_Counts(i,j)+1).The appearance of the
actual count value 255 is rare.  When displaying an image,it works best to use
the fill value as an overflow (i.e. brightest) value.

GCI position vector of DE spacecraft in kilometers. [SC_Pos_GCI]

GCI velocity vector of DE spacecraft in km/sec. [SC_Vel_GCI]

GCI spin axis unit vector of DE spacecraft. [SC_SpinV_GCI]

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DE_VS_EICS doi:10.48322/1gca-r323

Description

 Data: 96 second average fluxes for H+, O+, and He+ ions in 15 energy and 14
pitch angle bins. Including data uncertainties, data quality indicators and
spacecraft position information. 
References: 
1. Peterson, W.K., H.L. Collin, M.F. Doherty and C.M. Bjorklund, O+ and He+
restricted and extended (bi-modal) ion conic distributions, Geophys. Res.Lett.,
19, 1439, 1992. 
2. Collin, H.L., W.K. Peterson, J.F. Drake, and A.W. Yau, The helium components
of energetic terrestrial ion upflows: Their occurrence,  morphology, and
intensity, J. Geophys. Res., 93, 7558, 1988. 
3. Chiu, Y.T., R.M. Robinson, H.L. Collin, S. Chakrabarti, and G.R. Gladstone,
Exospheric imaging in the extreme ultraviolet, Geophys. Res. Lett., 17, 267,
1990. 
4. Robinson, R.M., Y.T. Chiu, R.C. Catura, H.L. Collin, D. Garrido and R. Smith,
Instrumental and observational requirements for space-based imaging of
magnetospheric emissions, Instrumentation for magnetospheric Imager, Proceedings
of the SPIE, The International Society for Optical Engineering,  Bellingham,
Washington, S. Chakrabarti, Ed., Vol. 1744, 13, 1992.
These data are are a validated sub set of the full resolution DE/EICS data set
archived in native VAX/VMS format at NSSDC under the DATA_SET_NAME: 
EICS_STAND_ALONE_TELEMETRY_FILE_SYSTEM. The data in this CDF are a super-set of
the data used to prepare the four large scale statistical studies referenced
above. 
The three data quality indicators N C and A described in the documentation
accompanying the EICS_STAND_ALONE_TELEMETRY_FILE_SYSTEM as well as several other
data quality and mode indicators are included here.  These data indicators are
described on line and are referenced from the DE project home page on the Space
Physics Data System.
URL: ftp://sierra.space..lockheed.com/DATA/de/DE_eics_home.html   IF Unavailable
try: http://leadbelley.lanl.gov/spds/project-pages-only.html 
Each physical cdf file contains data for an entire UT day.  The files have names
of the form YYDDD_EICS_DE.cdf
The file naming convention includes the UT day encoded in the NASA standard
YYDDD format. YY are the last two digits of the year and DDD is the day of year
with January 1 = 001. 
EICS data were not acquired in all 24 UT day intervals. If no input data were
available for a UT day period, no CDF file was produced.  IFEICS data were
available but there are no data available stisfying the input requirements for
this data set for a UT day interval, the CDF file contains one record of
CDF_FILL data entries for all record variable entries. 
Metadata providedby W.K. Peterson with the helpof Mona Kessel

Modification History

Created October, 1995 by W.K. Peterson
Add Q_FLAG_FILE_CORRUPTED variable to indicate intervals for which full data
quality information is not available. 10/10/95

Data Variable Descriptions

H+ number flux, at 15 energies (~0.01 to ~20keV) and 14 pitch angles (6 shown) [h_flux]

Negative fluxes reflect low count rates and background subtraction. The width of
lowest energy channel is variable.  Pitch angle coverage is NOT uniform. 
Conversion to velocity space density, calculations of density and other
operations involving division by a characteristic energy are limited in accuracy
by energy bands that are wide compared to the fall off of flux with energy.

---> ONE Standard deviation of H+ number flux at 15 energy and 14 pitch angle bins. [h_uncertainty]

Uncertainly estimated from the observed total signal counts.  The width of
lowest energy channel is variable.  Pitch angle coverage is NOT uniform.

O+ number flux, at 15 energies (~0.01 to ~20keV) and 14 pitch angles (6 shown) [o_flux]

Negative fluxes reflect low count rates and background subtraction. The width of
lowest energy channel is variable.  Pitch angle coverage is NOT uniform. 
Conversion to velocity space density, calculations of density and other
operations involving division by a characteristic energy are limited in accuracy
by energy bands that are wide compared to the fall off of flux with energy.

---> ONE Standard deviation of O+ number flux at 15 energy and 14 pitch angle bins. [o_uncertainty]

Uncertainly estimated from the observed total signal counts.  The width of
lowest energy channel is variable.  Pitch angle coverage is NOT uniform.

He+ number flux, at 15 energies (~0.01 to ~20keV) and 14 pitch angles (6 shown) [he_flux]

Negative fluxes reflect low count rates and background subtraction. The width of
lowest energy channel is variable.  Pitch angle coverage is NOT uniform. 
Conversion to velocity space density, calculations of density and other
operations involving division by a characteristic energy are limited in accuracy
by energy bands that are wide compared to the fall off of flux with energy.

ONE Standard deviation of He+ number fluxat 15 energy and 14 pitch angle bins. [he_uncertainty]

Uncertainly estimated from the observed total signal counts.  The width of
lowest energy channel is variable.  Pitch angle coverage is NOT uniform.

Background count rate interpolated to center time. scalar [INTERPOLATED_BACKGROUND]

Because the backgrounddoes, at times, vary rapidly on the 96 second averaging
period the background counting rate has been interpolated intime to reflect the
expected background counting rate at the center of the averaging interval.  The
ion flux may be time alised in regions of rapidly varying
INTERPOLATED_BACKGROUND.

---> One standard deviation of Interpolated Background. scalar [STANDARD_DEVIATION_OF_INTERPOLATED_BACKGROUND]

Determined from the total number ofbackground counts observed in the 96averaging
period.

Lowest Energy above the spacecraft potential accepted. scalar [Low_energy_cut_off]

The Center_energy of the lowest energy channel must be corrected for
Low_energy_cut_off above 0.015 keV

Bitwise combination of He_data,N_flag, C_flag, A_flag, Noisy_flag, Short_flag, and PA_coverage_flag. scalar [Mode_error_flag]

This variable is displayed as a bitwisespectrogram by the idl check_cdf.pro code
available from pete@willow.space.lockheed.com    Interpretation of Values: 0/1:
0=He+ data. 1=No He+ data 0/2: 0=NOT BCLIST N flag indicating that data are
missing or care must be taken in processing or interpreting them. 2= N flag on.
0/4: 0=NOT BCLIST C flag indicating that data in the lowest energy channel are
contaminated by extra counts from a EUV photoionization of residual gas in the
input aperture. 4=C flag on. 0/8: 0=NOT BCLIST A flag indicating that full
attitude are available in the full archived data file. Attitude data are not
required or available for the pitch angle organized data processed into the cdf
files here. 8= A flag on. 0/16: 0=Not NOISY data  Flag manually entered after
scan of summary spectrogram 16= Noisy flag on. 0/32: 0=NOT TOO SHORT. 
Interpretation of Noisy data and other problems was difficult from files
containing less than about 7 minutes of data.  This flag was manually set from
reading summary spectrograms. 32= Data interval too short.  0/64: 0=Complete
pitch angle coverage determined from visual inspection of summary spectrograms
64= Incomplete pitch angle coverage. 0/128:  See Q_FLAG_FILE_CORRUPTED variable
described below.

He+ data available flag 0=data for he+; 1=no he+ data [He_data]

He+ fluxes are available for approximately 50% of the data intervalsin this
archive.  He_data is set on a per record basis

---> Data valid flag 0=good; 1=Not available or use with caution [N_flag]

Some valid data may be included in the telemetry segment, but some of the data
in the segment are invalid and must not be includedin long term average data
sets.This is the N flag described in the EICSDATA.LIS file and other 
documentation accompanying the EICS_STAND_ALONE_TELEMETRY_FILE_SYSTEM from NSSDC
or on line on the DE project home page on the Space Physics Data System.  This
flag is set on a telemetryinterval (segment) basis.

---> Sun Pulse Flag0=good; 1=use data from the lowest energy channel with caution. [C_flag]

Set to 1 when a visual examination of  color spectrogram showed the lowest
energy channel included a spurious count rate caused by the photoionization of
residual neutral gases in in the preacceleration region of the spectrometer as
described in Shelley et al. Geophys. Res. Lett. 9, p942, 1982. This is the C
data quality flag described in the EICSDATA.LIS file and other  documentation
accompanying the EICS_STAND_ALONE_TELEMETRY_FILE_SYSTEM from NSSDC or on line on
the DE project home page on the Space Physics Data System.

---> Attitude Available Flag 0: Source data CAN provide sensor orientation relative to the spacecraft velocity. 1: CAN NOT [A_flag]

Information variable. Does not apply to data in this CDF.  If set to 0
information about the direction of plasma motion with respect to the satellite
motion may be obtained from the the full resolution
EICS_STAND_ALONE_TELEMETRY_FILE_SYSTEM archived at NSSDC. This is the A data
quality flag described in the EICSDATA.LIS file and other  documentation
accompanying the EICS_STAND_ALONE_TELEMETRY_FILE_SYSTEM from NSSDC or on line on
the DE project home page on the Space Physics Data System.

---> Supplemental Data Valid Flag #1 0=good; 1= Telemetry interval contains unphysically high signal levels [Noisy_flag]

This flag is set on a telemetryinterval basis.  A visual examination of color
spectrograms indicated some 96 second dataintervals with extremely high counting
rates.  These intervals were identified by their characteristic patchyness on
energy-time and angle-time spectrograms.  Data from intervals where the
Noisy_flag=1 WERE NOT included in the large-scale statistical studies referenced
in the global attributes.Some valid data may be included in the telemetry
segment

---> Supplemental Data Valid Flag #2 0=good; 1=Too short to evaluate data quality. [Short_flag]

1 indicates that  a visual examination of color spectrograms was not possible
because the data interval was too short.  The data quality flags that depend on
visual examination are:  C_flag, A_flag, Noisy_flag, and PA_coverage_flag.

---> Pitch Angle Coverage Flag 0=good; 1=Incomplete PA coverage. [PA_coverage_flag]

Data for some pitch angle ranges may contain fill indicating that the full pitch
angle range was notsampled.  This occurs when the magnetic field does not lie
within  the satellite spin plane.    The flag is set to 1 when a visual
examination of color spectrograms show that data are not available in all pitch
angle bins.  This flag is set on a telemetry segment basis.

---> Quality Flags Corrupted 0=OK ; 1= Information Lost [Q_FLAG_FILE_CORRUPTED]

Quality flag information for DE/EICSwas created in a keyed file using
VMSspecific file management.  In the almost15 years this file has been
maintained records for some time intervals have become corrupted.  Some quality
informationcan be found in the data catalog available with the DE/EICS Stand
Alone Telemetry Files (SATF) from NSSDC

Geographic Position Altitude above the geoid, latitude and longitude. [Geographic_position]

Values obtained from various sources.

Geomagnetic Position Magnetic local time, Invariant latitude and geomagnetic latitude. [Geomagnetic_position]

Values obtained from various sources.

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DMSP-F06_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

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DMSP-F07_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

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DMSP-F08_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

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DMSP-F09_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

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DMSP-F12_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

Distance from center of Earth in km. [SC_GEOCENTRIC_R]

Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Electron counts as observed; no corrections. [ELE_COUNTS_OBS]

Background electron count estimate. [ELE_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each observation and energy
channel.

Electron differential energy flux (ev/cm2/delta-eV/ster/s). [ELE_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ELE_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in electron differential energy flux (fractional). [ELE_DIFF_ENERGY_FLUX_STD]

Electron total energy flux integrated over energy (eV/cm2/ster/s). [ELE_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ELE_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in electron total energy flux integrated over energy (fractional). [ELE_TOTAL_ENERGY_FLUX_STD]

Average electron energy (eV). [ELE_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ELE_AVG_ENERGY_STD

Estimated relative uncertainty in average electron energy (fractional). [ELE_AVG_ENERGY_STD]

Ion counts as observed; no corrections. [ION_COUNTS_OBS]

Background ion count estimate. [ION_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each observation and energy
channel.

Ion differential energy flux (ev/cm2/delta-eV/ster/s). [ION_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ION_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in ion differential energy flux (fractional). [ION_DIFF_ENERGY_FLUX_STD]

Ion total energy flux integrated over energy (eV/cm2/ster/s). [ION_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ION_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in ion total energy flux integrated over energy (fractional). [ION_TOTAL_ENERGY_FLUX_STD]

Average ion energy (eV). [ION_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ION_AVG_ENERGY_STD

Estimated relative uncertainty in ion average energy (fractional). [ION_AVG_ENERGY_STD]

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DMSP-F13_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.
Version 1.1.2
Added ORBIT_INDEX and AURORAL_REGION variables
Version 1.1.3
Added AURORAL_BOUNDARY_FOM figure of merit for dynamic auroral boundary
determination variable
Version 1.1.4
Removed AURORAL_REGION and AURORAL_BOUNDARY_FOM variables. See
github.com/lkilcommons/ssj_auroral_boundary
Version 1.1.5
Removed ORBIT_INDEX to make compatible with CDAWeb 1,1,2 master CDF

Data Variable Descriptions

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

Distance from center of Earth in km. [SC_GEOCENTRIC_R]

Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Electron counts as observed; no corrections. [ELE_COUNTS_OBS]

Background electron count estimate. [ELE_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

Electron differential energy flux (ev/cm2/delta-eV/ster/s). [ELE_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ELE_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in electron differential energy flux (fractional). [ELE_DIFF_ENERGY_FLUX_STD]

Electron total energy flux integrated over energy (eV/cm2/ster/s). [ELE_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ELE_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in electron total energy flux integrated over energy (fractional). [ELE_TOTAL_ENERGY_FLUX_STD]

Average electron energy (eV). [ELE_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ELE_AVG_ENERGY_STD

Estimated relative uncertainty in average electron energy (fractional). [ELE_AVG_ENERGY_STD]

Ion counts as observed; no corrections. [ION_COUNTS_OBS]

Background ion count estimate. [ION_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

Ion differential energy flux (ev/cm2/delta-eV/ster/s). [ION_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ION_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in ion differential energy flux (fractional). [ION_DIFF_ENERGY_FLUX_STD]

Ion total energy flux integrated over energy (eV/cm2/ster/s). [ION_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ION_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in ion total energy flux integrated over energy (fractional). [ION_TOTAL_ENERGY_FLUX_STD]

Average ion energy (eV). [ION_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ION_AVG_ENERGY_STD

Estimated relative uncertainty in ion average energy (fractional). [ION_AVG_ENERGY_STD]

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DMSP-F14_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

Distance from center of Earth in km. [SC_GEOCENTRIC_R]

Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Electron counts as observed; no corrections. [ELE_COUNTS_OBS]

Background electron count estimate. [ELE_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each observation and energy
channel.

Electron differential energy flux (ev/cm2/delta-eV/ster/s). [ELE_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ELE_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in electron differential energy flux (fractional). [ELE_DIFF_ENERGY_FLUX_STD]

Electron total energy flux integrated over energy (eV/cm2/ster/s). [ELE_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ELE_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in electron total energy flux integrated over energy (fractional). [ELE_TOTAL_ENERGY_FLUX_STD]

Average electron energy (eV). [ELE_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ELE_AVG_ENERGY_STD

Estimated relative uncertainty in average electron energy (fractional). [ELE_AVG_ENERGY_STD]

Ion counts as observed; no corrections. [ION_COUNTS_OBS]

Background ion count estimate. [ION_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each observation and energy
channel.

Ion differential energy flux (ev/cm2/delta-eV/ster/s). [ION_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ION_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in ion differential energy flux (fractional). [ION_DIFF_ENERGY_FLUX_STD]

Ion total energy flux integrated over energy (eV/cm2/ster/s). [ION_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ION_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in ion total energy flux integrated over energy (fractional). [ION_TOTAL_ENERGY_FLUX_STD]

Average ion energy (eV). [ION_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ION_AVG_ENERGY_STD

Estimated relative uncertainty in ion average energy (fractional). [ION_AVG_ENERGY_STD]

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DMSP-F15_SSJ_PRECIPITATING-ELECTRONS-IONS

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

Distance from center of Earth in km. [SC_GEOCENTRIC_R]

Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Electron counts as observed; no corrections. [ELE_COUNTS_OBS]

Background electron count estimate. [ELE_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each observation and energy
channel.

Electron differential energy flux (ev/cm2/delta-eV/ster/s). [ELE_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ELE_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in electron differential energy flux (fractional). [ELE_DIFF_ENERGY_FLUX_STD]

Electron total energy flux integrated over energy (eV/cm2/ster/s). [ELE_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ELE_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in electron total energy flux integrated over energy (fractional). [ELE_TOTAL_ENERGY_FLUX_STD]

Average electron energy (eV). [ELE_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ELE_AVG_ENERGY_STD

Estimated relative uncertainty in average electron energy (fractional). [ELE_AVG_ENERGY_STD]

Ion counts as observed; no corrections. [ION_COUNTS_OBS]

Background ion count estimate. [ION_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each observation and energy
channel.

Ion differential energy flux (ev/cm2/delta-eV/ster/s). [ION_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ION_DIFF_ENERGY_FLUX_STD

Estimated relative uncertainty in ion differential energy flux (fractional). [ION_DIFF_ENERGY_FLUX_STD]

Ion total energy flux integrated over energy (eV/cm2/ster/s). [ION_TOTAL_ENERGY_FLUX]

Uncertainty represented in variable ION_TOTAL_ENERGY_FLUX_STD

Estimated relative uncertainty in ion total energy flux integrated over energy (fractional). [ION_TOTAL_ENERGY_FLUX_STD]

Average ion energy (eV). [ION_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. Uncertainty represented in
variable ION_AVG_ENERGY_STD

Estimated relative uncertainty in ion average energy (fractional). [ION_AVG_ENERGY_STD]

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DMSP-F16_SSIES-3_THERMAL-PLASMA doi:10.48322/hcdm-vz96
Proper citations should include the "Accessed on date" in the form .

Description

The Special Sensors-Ions, Electrons, and Scintillation (SSIES) thermal plasma
analysis package is a suite of instruments built by the Center for Space
Sciences at the University of Texas at Dallas and flown on a number of the DMSP
satellites. SSIESS includes a Retarding Potential Analyzer (RPA), Ion Drift
meter (IDM), scintillation meter, and Langmuir probe.

Data Variable Descriptions

Vx - median filtered and smoothed ion flow in the ram direction [vx]

median filtered and smoothed ion flow in the ram direction from the fits to the
RPA curve

----> Vx quality flag [READ QUALITY FLAG Document: link below] [vxqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

----> Vx root mean square of the RPA fit [vxrms]

root mean square of the fit to the RPA curve giving an indication of the quality
of the RPA data for this sweep

Vx - original unfiltered Vx flow [vxraw]

the unfiltered Vx flow values calculated by the RPA fitting routine

Vy - ion flow in the horizontal crosstrack direction [vy]

crosstrack horizontal ion flow from IDM, positive is in the sunward direction
regardless of the orientation of the orbit, data taken in two modes: normal and
slow (see nmbpts)

----> quality flag for Vy data [READ QUALITY FLAG Document: link below] [vyqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

----> standard deviation of the Vy flow [vyrms]

standard deviation of the six Vy samples taken per second in the normal mode,
fill data in slow mode

----> roughness parameter of Vy [dmhrough]

roughness parameter of Vy defined as (delta Vy / averaged Vy)

Vz - ion flow in the vertical crosstrack direction [vz]

crosstrack vertical ion flow from IDM, positive is in the upward direction, data
taken in two modes: normal and slow (see nmbpts)

----> quality flag for Vz data [READ QUALITY FLAG Document: link below] [vzqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

----> standard deviation of the Vz flow [vzrms]

standard deviation of the six Vz samples taken per second in the normal mode,
fill data in slow mode

----> roughness parameter of Vz (delta Vz / averaged Vz) [dmvrough]

roughness parameter of Vy defined as (delta Vy / averaged Vy)

ion temperature [temp]

temperature of the ions in the plasma calculated from the fit to the RPA curve

----> Quality flag for the ion temperature [READ QUALITY FLAG Document: link below] [tempqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

electron temperature [te]

the electron temperature based on an onboard calculation of the Langmuir probe
sweep which occurs once every 4 s

Ni calculated from the RPA [dens]

Ion density of the plasma calculated from the fit to the RPA curve

----> quality flag for the ion density [READ QUALITY FLAG Document: link below] [densqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

Ni from scintillation meter [ductdens]

the average of the 24 Hz samples of the ion density by the scintillation meter,
because of its large aperture this is considered the best meaure of the ion
density

----> roughness parameter of SM density [ductdensrough]

roughness parameter of scintillation meter ion density  defined as (delta Ni/
averaged Ni)

Ni measured from the RPA at 0 volts [dens0v]

during each RPA sweep there is a point where the repeller voltage is 0 V so all
the ions reach the collector, this is the ion density based on that measurement

Ni from the IDM [dmdens]

the ion density based on the collector current in the IDM, because some or all
of the light ions are excluded this density should always be equal to or less
than the other ion densities

fractional amount of H+ ions in plasma [frach]

fractional amount of the plasma that is H+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional H+ [READ QUALITY FLAG Document: link below] [frachqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

fractional amount of He+ ions in plasma [frache]

fractional amount of the plasma that is He+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional He+ [READ QUALITY FLAG Document: link below] [frachequal]

1-good 2-fair 3-caution 4-bad 5-uncertain

fractional amount of O+ ions in plasma [fraco]

fractional amount of the plasma that is O+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional O+ [READ QUALITY FLAG Document: link below] [fracoqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

electron background monitor - high energy particle currents detected by the RPA [ebm]

once every 2 s the RPA repeller voltage is set so high that only high energy
electrons or ions reach the collector. A large current indicates high-energy
particles or photo-electron production (a sun-glint).

Overall quality flag for RPA data [READ QUALITY FLAG Document: link below] [corrpaqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

flag for RPA sweep direction [READ QUALITY FLAG Document: link below] [rpainfo]

1-retarding potential increasing 2-retarding potential decreasing

geographical latitude [glat]

geographic latitude of s/c

geographic east longitude [glon]

geographic east longitude of s/c

magnetic latitude, mapped to 120 km [mlat]

magnetic latitude of field line at s/c mapped to 120 km

magnetic local time, mapped to 120 km [mlt]

magnetic local time of field line at s/c mapped to 120 km

solar zenith angle [sza]

angle between the sun-earth line and the s/c-center of earth line

altitude [alt]

altitude of the s/c above earth’s surface

[Labels on plots] magnetic latitude, mapped to 120 km [mlat_tt]

magnetic latitude of field line at s/c mapped to 120 km

[Labels on plots] magnetic local time, mapped to 120 km [mlt_tt]

magnetic local time of field line at s/c mapped to 120 km

[Labels on plots] geographical latitude [glat_tt]

geographic latitude of s/c

[Labels on plots] geographic east longitude [glon_tt]

geographic east longitude of s/c

[Labels on plots] solar zenith angle [sza_tt]

angle between the sun-earth line and the s/c-center of earth line

[Labels on plots] altitude [alt_tt]

altitude of the s/c above earth’s surface

number of data points in the Vy - Vz average [nmbot]

the IDM operates in two modes: normal mode takes six horizontal and six vertical
samples per second, slow mode is for low density conditions where only one
sample is taken each second and alternates between directions

overall quality flag for the IDM data [READ QUALITY FLAG Document: link below] [idmqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

spacecraft velocity [scvel]

orbital velocity of the spacecraft

potential difference between SSIES instruments and spacecraft ground [rpaground]

the DMSP spacecraft charges negative relative to the plasma ground so SSIES is
electrically insolated and driven positive relative to spacecraft ground to keep
the instrument near the plasma ground

potential of the SSIES instruments relative to the plasma ground [pot]

all the SSIES instruments are held near the plasma ground potential, nominally
about -1 V relative to the plasma, this value is calculated from the RPA curve
fit, shown as \“SC Potential\” on the plots

north component of Earths magnetic field (IGRF) [bx]

northward component of the Earths magnetic field at the spacecrafts location
calculated by the IGRF model

east component of Earths magnetic field (IGRF) [by]

eastward component of the Earths magnetic field at the spacecrafts location
calculated by the IGRF model

vertical downward component of Earths magnetic field (IGRF) [bz]

vertical downward component of the Earths magnetic field at the spacecrafts
location calculated by the IGRF model

corotation velocity of ionosphere in the ram direction [corvelx]

the ram component (x) of the corotation speed of the ionosphere at the
spacecrafts location

corotation velocity of ionosphere in the horizontal crosstrack direction [corvely]

the crosstrack horizontal component (y) of the corotation speed of the
ionosphere at the spacecrafts location

corotation velocity of ionosphere in the vertical direction [corvelz]

the crosstrack vertical component (z) of the corotation speed of the ionosphere
at the spacecrafts location, since DMSP is in a circular orbit, this value is
zero

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DMSP-F16_SSJ_PRECIPITATING-ELECTRONS-IONS doi:10.48322/1rnz-f067

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

Electrons 30eV-30keV: Electron counts as observed; no corrections. [ELE_COUNTS_OBS]

-----> Background electron count estimate. [ELE_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

--> Electron differential energy flux (eV/cm2/delta-eV/ster/s). [ELE_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ELE_DIFF_ENERGY_FLUX_STD

-----> Estimated uncertainty in electron differential energy flux (fractional). [ELE_DIFF_ENERGY_FLUX_STD]

--> Electron total energy flux integrated over energy (eV/cm2/ster/s). [ELE_TOTAL_ENERGY_FLUX]

 DELTA_PLUS_VAR CDF_CHAR ELE_TOTAL_ENERGY_FLUX_STD DELTA_MINUS_VAR CDF_CHAR
ELE_TOTAL_ENERGY_FLUX_STD

-----> Estimated uncertainty in electron total energy flux integrated over energy (fractional). [ELE_TOTAL_ENERGY_FLUX_STD]

--> Electron average energy (eV). [ELE_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux.  DELTA_PLUS_VAR CDF_CHAR
ELE_AVG_ENERGY_STD DELTA_MINUS_VAR CDF_CHAR ELE_AVG_ENERGY_STD

-----> Estimated uncertainty in electron average energy (fractional). [ELE_AVG_ENERGY_STD]

Ions 30eV-30keV: Ion counts as observed; no corrections. [ION_COUNTS_OBS]

-----> Background ion count estimate. [ION_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

--> Ion differential energy flux (eV/cm2/delta-eV/ster/s). [ION_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ION_DIFF_ENERGY_FLUX_STD

-----> Estimated uncertainty in ion differential energy flux (fractional). [ION_DIFF_ENERGY_FLUX_STD]

--> Ion total energy flux integrated over energy (eV/cm2/ster/s). [ION_TOTAL_ENERGY_FLUX]

 DELTA_PLUS_VAR CDF_CHAR ION_TOTAL_ENERGY_FLUX_STD DELTA_MINUS_VAR CDF_CHAR
ION_TOTAL_ENERGY_FLUX_STD

-----> Estimated uncertainty in ion total energy flux integrated over energy (fractional). [ION_TOTAL_ENERGY_FLUX_STD]

--> Ion average energy (eV). [ION_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. DELTA_PLUS_VAR CDF_CHAR
ION_AVG_ENERGY_STD DELTA_MINUS_VAR CDF_CHAR ION_AVG_ENERGY_STD

-----> Estimated uncertainty in ion average energy (fractional). [ION_AVG_ENERGY_STD]

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

--> Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

--> Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

--> Distance from center of Earth in km. [SC_GEOCENTRIC_R]

--> Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

--> Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

--> Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

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DMSP-F16_SSM_MAGNETOMETER doi:10.48322/bh8f-yy31

Description

Magetic measurements taken at nominally 850km altitude using a 3-axis fluxgate
magnetometer.  Please contact Rob.Redmon@noaa.gov or
liam.kilcommons@colorado.edu with questions and comments. Many individuals made
important contributions including: F. Rich, G. Wilson, D. Ober, R. Redmon, D.
Knipp, L. Kilcommons, P. Alken.

Modification History

This is version 1, beta.
Version 1.0.1
Apex and geocentric east-north-up coordinates added. Polynomial baseline
corrected versions of perturabtions added.
Version 1.0.2
Auroral region (from SSJ boundary identification) and orbit index added 
Version 1.0.3
Added Spacecraft Along Track Unit Vector
Switched naming convention from corrected ending in _COR to original ending in
_ORIG, so that MFIT corrected data would appear to be default. Removed any
variables that were uncorrected except for spacecraft coordinates.
Version 1.0.4
Added recomputed magnetic perturbations, i.e. recomputed the IGRF field for the
improved locations, and subtracted it from the observed total field. Added
spacecraft across track unit vector. Switch SC_APEX_LON to -180. to 180. instead
of 0.-360.

Data Variable Descriptions

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

Distance from center of Earth in km. [SC_GEOCENTRIC_R]

Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Original measured field (x,y,z) in nT in spacecraft frame. [B_SC_OBS_ORIG]

X = Geodedic nadir (down).Y = Along Spacecraft Track (ram),.Z = Across-Track
Right .NOTE: This pertrubations in this variable have been recomputed from the
observed B-field.IGRF11 was run using this day as epoch and new, more accurate
geocentric location was rotatedinto spacecraft coordinates and removed.

delta-B (Original measured B - Modeled IGRF field) (x,y,z) in nT in spacecraft frame. [DELTA_B_SC_ORIG]

X = Geodedic nadir (down).Y = Along Spacecraft Track (ram),.Z = Across-Track
Right

Baseline Corrected delta-B in nT rotated into geocentric spherical (east-north-up) coordinates. [DELTA_B_GEO]

Finite difference between adjacent points on spacecraft track was used to
determine along and across track unit vectors in GEO. No altitude change between
adjacent points was assumed..Baseline correction (F. Rich's MFIT procedure) is
polynomial fit every half-pass to each component of Delta-B in spacecraft
coordinates using only data from region equatorward of DMSP auroral boundary
from CEDAR Database.

Baseline Corrected delta-B in nT rotated into Modified Apex Coordinates with Reference Height 110 km. [DELTA_B_APX]

Coordinates transformed with apex-python (NCAR HAO). Reference Altitude = 110km,
see Richmond, J. Geomag. Geoelec. ,1995.Baseline correction (F. Rich's MFIT
procedure) is polynomial fit every half-pass to each component of Delta-B in
spacecraft coordinates using only data from region equatorward of DMSP auroral
boundary from CEDAR Database.

Baseline Corrected delta-B in nT in spacecraft frame. [DELTA_B_SC]

X = Geodedic nadir (down), Y = Along Spacecraft Track (ram), Z = Across-Track
Right Baseline correction (F. Rich's MFIT procedure) is polynomial fit every
half-pass to each component of Delta-B in spacecraft coordinates using only data
from region equatorward of DMSP auroral boundary from CEDAR Database.

Modified Apex Geomagnetic Latitude (Reference Height 110km) [SC_APEX_LAT]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Modified Apex Geomagnetic Longitude (Reference Height 110km) [SC_APEX_LON]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Modified Apex Geomagnic Local Time (Reference Height 110km) [SC_APEX_MLT]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Numerical code for auroral region of spacecraft location (1=Equatorial,2=Auroral,3=Polar) [AURORAL_REGION]

0 = No boundary identified, 1 = Equatorward of the auroral zone, 2 = In the
auroral zone, 3 = Polar cap

Figure of Merit for Auroral Boundary Determination [AURORAL_BOUNDARY_FOM]

Typical range 0-4. Less than 2 is suspect..See DMSP CDF user manual for full
specification of FOM computation.

Integer representing the orbit of the day, signed by hemisphere (>0 Northern, <0 Southern). [ORBIT_INDEX]

Orbit start and end determined by crossings of the Apex magnetic equator. Zero
for before first equator crossing of the day.

Unit vector in the direction of spacecraft velocity (ram) in geocentric coordintes [SC_ALONG_GEO]

This is an estimate, based on a spherical trigonometry approach using a
great-circle arc between adjacent points (see user manual).

Unit vector across the spacecraft track to the left ( orthogonal to the direction of spacecraft velocity (ram) ) in geocentric coordintes. [SC_ACROSS_GEO]

This is an estimate, based on a spherical trigonometry approach using a
great-circle arc between adjacent points (see user manual).

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DMSP-F17_SSIES-3_THERMAL-PLASMA doi:10.48322/3skz-xt83
Proper citations should include the "Accessed on date" in the form .

Description

The Special Sensors-Ions, Electrons, and Scintillation (SSIES) thermal plasma
analysis package is a suite of instruments built by the Center for Space
Sciences at the University of Texas at Dallas and flown on a number of the DMSP
satellites. SSIESS includes a Retarding Potential Analyzer (RPA), Ion Drift
meter (IDM), scintillation meter, and Langmuir probe.

Data Variable Descriptions

Vx - median filtered and smoothed ion flow in the ram direction [vx]

median filtered and smoothed ion flow in the ram direction from the fits to the
RPA curve

----> Vx quality flag [READ QUALITY FLAG Document: link below] [vxqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

----> Vx root mean square of the RPA fit [vxrms]

root mean square of the fit to the RPA curve giving an indication of the quality
of the RPA data for this sweep

Vx - original unfiltered Vx flow [vxraw]

the unfiltered Vx flow values calculated by the RPA fitting routine

Vy - ion flow in the horizontal crosstrack direction [vy]

crosstrack horizontal ion flow from IDM, positive is in the sunward direction
regardless of the orientation of the orbit, data taken in two modes: normal and
slow (see nmbpts)

----> quality flag for Vy data [READ QUALITY FLAG Document: link below] [vyqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

----> standard deviation of the Vy flow [vyrms]

standard deviation of the six Vy samples taken per second in the normal mode,
fill data in slow mode

----> roughness parameter of Vy [dmhrough]

roughness parameter of Vy defined as (delta Vy / averaged Vy)

Vz - ion flow in the vertical crosstrack direction [vz]

crosstrack vertical ion flow from IDM, positive is in the upward direction, data
taken in two modes: normal and slow (see nmbpts)

----> quality flag for Vz data [READ QUALITY FLAG Document: link below] [vzqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

----> standard deviation of the Vz flow [vzrms]

standard deviation of the six Vz samples taken per second in the normal mode,
fill data in slow mode

----> roughness parameter of Vz (delta Vz / averaged Vz) [dmvrough]

roughness parameter of Vy defined as (delta Vy / averaged Vy)

ion temperature [temp]

temperature of the ions in the plasma calculated from the fit to the RPA curve

----> Quality flag for the ion temperature [READ QUALITY FLAG Document: link below] [tempqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

electron temperature [te]

the electron temperature based on an onboard calculation of the Langmuir probe
sweep which occurs once every 4 s

Ni calculated from the RPA [dens]

Ion density of the plasma calculated from the fit to the RPA curve

----> quality flag for the ion density [READ QUALITY FLAG Document: link below] [densqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

Ni from scintillation meter [ductdens]

the average of the 24 Hz samples of the ion density by the scintillation meter,
because of its large aperture this is considered the best meaure of the ion
density

----> roughness parameter of SM density [ductdensrough]

roughness parameter of scintillation meter ion density  defined as (delta Ni/
averaged Ni)

Ni measured from the RPA at 0 volts [dens0v]

during each RPA sweep there is a point where the repeller voltage is 0 V so all
the ions reach the collector, this is the ion density based on that measurement

Ni from the IDM [dmdens]

the ion density based on the collector current in the IDM, because some or all
of the light ions are excluded this density should always be equal to or less
than the other ion densities

fractional amount of H+ ions in plasma [frach]

fractional amount of the plasma that is H+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional H+ [READ QUALITY FLAG Document: link below] [frachqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

fractional amount of He+ ions in plasma [frache]

fractional amount of the plasma that is He+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional He+ [READ QUALITY FLAG Document: link below] [frachequal]

1-good 2-fair 3-caution 4-bad 5-uncertain

fractional amount of O+ ions in plasma [fraco]

fractional amount of the plasma that is O+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional O+ [READ QUALITY FLAG Document: link below] [fracoqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

electron background monitor - high energy particle currents detected by the RPA [ebm]

once every 2 s the RPA repeller voltage is set so high that only high energy
electrons or ions reach the collector. A large current indicates high-energy
particles or photo-electron production (a sun-glint).

Overall quality flag for RPA data [READ QUALITY FLAG Document: link below] [corrpaqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

flag for RPA sweep direction [READ QUALITY FLAG Document: link below] [rpainfo]

1-retarding potential increasing 2-retarding potential decreasing

geographical latitude [glat]

geographic latitude of s/c

geographic east longitude [glon]

geographic east longitude of s/c

magnetic latitude, mapped to 120 km [mlat]

magnetic latitude of field line at s/c mapped to 120 km

magnetic local time, mapped to 120 km [mlt]

magnetic local time of field line at s/c mapped to 120 km

solar zenith angle [sza]

angle between the sun-earth line and the s/c-center of earth line

altitude [alt]

altitude of the s/c above earth’s surface

[Labels on plots] magnetic latitude, mapped to 120 km [mlat_tt]

magnetic latitude of field line at s/c mapped to 120 km

[Labels on plots] magnetic local time, mapped to 120 km [mlt_tt]

magnetic local time of field line at s/c mapped to 120 km

[Labels on plots] geographical latitude [glat_tt]

geographic latitude of s/c

[Labels on plots] geographic east longitude [glon_tt]

geographic east longitude of s/c

[Labels on plots] solar zenith angle [sza_tt]

angle between the sun-earth line and the s/c-center of earth line

[Labels on plots] altitude [alt_tt]

altitude of the s/c above earth’s surface

number of data points in the Vy - Vz average [nmbot]

the IDM operates in two modes: normal mode takes six horizontal and six vertical
samples per second, slow mode is for low density conditions where only one
sample is taken each second and alternates between directions

overall quality flag for the IDM data [READ QUALITY FLAG Document: link below] [idmqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

spacecraft velocity [scvel]

orbital velocity of the spacecraft

potential difference between SSIES instruments and spacecraft ground [rpaground]

the DMSP spacecraft charges negative relative to the plasma ground so SSIES is
electrically insolated and driven positive relative to spacecraft ground to keep
the instrument near the plasma ground

potential of the SSIES instruments relative to the plasma ground [pot]

all the SSIES instruments are held near the plasma ground potential, nominally
about -1 V relative to the plasma, this value is calculated from the RPA curve
fit, shown as \“SC Potential\” on the plots

north component of Earths magnetic field (IGRF) [bx]

northward component of the Earths magnetic field at the spacecrafts location
calculated by the IGRF model

east component of Earths magnetic field (IGRF) [by]

eastward component of the Earths magnetic field at the spacecrafts location
calculated by the IGRF model

vertical downward component of Earths magnetic field (IGRF) [bz]

vertical downward component of the Earths magnetic field at the spacecrafts
location calculated by the IGRF model

corotation velocity of ionosphere in the ram direction [corvelx]

the ram component (x) of the corotation speed of the ionosphere at the
spacecrafts location

corotation velocity of ionosphere in the horizontal crosstrack direction [corvely]

the crosstrack horizontal component (y) of the corotation speed of the
ionosphere at the spacecrafts location

corotation velocity of ionosphere in the vertical direction [corvelz]

the crosstrack vertical component (z) of the corotation speed of the ionosphere
at the spacecrafts location, since DMSP is in a circular orbit, this value is
zero

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DMSP-F17_SSJ_PRECIPITATING-ELECTRONS-IONS doi:10.48322/zjs1-0y88

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

Electrons 30eV-30keV: Electron counts as observed; no corrections. [ELE_COUNTS_OBS]

-----> Background electron count estimate. [ELE_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

--> Electron differential energy flux (ev/cm2/delta-eV/ster/s). [ELE_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ELE_DIFF_ENERGY_FLUX_STD

-----> Estimated uncertainty in electron differential energy flux (fractional). [ELE_DIFF_ENERGY_FLUX_STD]

--> Electron total energy flux integrated over energy (eV/cm2/ster/s). [ELE_TOTAL_ENERGY_FLUX]

 DELTA_PLUS_VAR CDF_CHAR ELE_TOTAL_ENERGY_FLUX_STD DELTA_MINUS_VAR CDF_CHAR
ELE_TOTAL_ENERGY_FLUX_STD

-----> Estimated uncertainty in electron total energy flux integrated over energy (fractional). [ELE_TOTAL_ENERGY_FLUX_STD]

--> Electron average energy (eV). [ELE_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux.  DELTA_PLUS_VAR CDF_CHAR
ELE_AVG_ENERGY_STD DELTA_MINUS_VAR CDF_CHAR ELE_AVG_ENERGY_STD

-----> Estimated uncertainty in electron average energy (fractional). [ELE_AVG_ENERGY_STD]

Ions 30eV-30keV: Ion counts as observed; no corrections. [ION_COUNTS_OBS]

-----> Background ion count estimate. [ION_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

--> Ion differential energy flux (ev/cm2/delta-eV/ster/s). [ION_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ION_DIFF_ENERGY_FLUX_STD

-----> Estimated uncertainty in ion differential energy flux (fractional). [ION_DIFF_ENERGY_FLUX_STD]

--> Ion total energy flux integrated over energy (eV/cm2/ster/s). [ION_TOTAL_ENERGY_FLUX]

 DELTA_PLUS_VAR CDF_CHAR ION_TOTAL_ENERGY_FLUX_STD DELTA_MINUS_VAR CDF_CHAR
ION_TOTAL_ENERGY_FLUX_STD

-----> Estimated uncertainty in ion total energy flux integrated over energy (fractional). [ION_TOTAL_ENERGY_FLUX_STD]

--> Ion average energy (eV). [ION_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. DELTA_PLUS_VAR CDF_CHAR
ION_AVG_ENERGY_STD DELTA_MINUS_VAR CDF_CHAR ION_AVG_ENERGY_STD

-----> Estimated uncertainty in ion average energy (fractional). [ION_AVG_ENERGY_STD]

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

--> Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

--> Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

--> Distance from center of Earth in km. [SC_GEOCENTRIC_R]

--> Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

--> Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

--> Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

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DMSP-F17_SSM_MAGNETOMETER doi:10.48322/1c9w-jd85

Description

Magetic measurements taken at nominally 850km altitude using a 3-axis fluxgate
magnetometer.  Please contact Rob.Redmon@noaa.gov or
liam.kilcommons@colorado.edu with questions and comments. Many individuals made
important contributions including: F. Rich, G. Wilson, D. Ober, R. Redmon, D.
Knipp, L. Kilcommons, P. Alken.

Modification History

This is version 1, beta.
Version 1.0.1
Apex and geocentric east-north-up coordinates added. Polynomial baseline
corrected versions of perturabtions added.
Version 1.0.2
Auroral region (from SSJ boundary identification) and orbit index added 
Version 1.0.3
Added Spacecraft Along Track Unit Vector
Switched naming convention from corrected ending in _COR to original ending in
_ORIG, so that MFIT corrected data would appear to be default. Removed any
variables that were uncorrected except for spacecraft coordinates.
Version 1.0.4
Added recomputed magnetic perturbations, i.e. recomputed the IGRF field for the
improved locations, and subtracted it from the observed total field. Added
spacecraft across track unit vector. Switch SC_APEX_LON to -180. to 180. instead
of 0.-360.

Data Variable Descriptions

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

Distance from center of Earth in km. [SC_GEOCENTRIC_R]

Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Original measured field (x,y,z) in nT in spacecraft frame. [B_SC_OBS_ORIG]

X = Geodedic nadir (down).Y = Along Spacecraft Track (ram),.Z = Across-Track
Right .NOTE: This pertrubations in this variable have been recomputed from the
observed B-field.IGRF11 was run using this day as epoch and new, more accurate
geocentric location was rotatedinto spacecraft coordinates and removed.

delta-B (Original measured B - Modeled IGRF field) (x,y,z) in nT in spacecraft frame. [DELTA_B_SC_ORIG]

X = Geodedic nadir (down).Y = Along Spacecraft Track (ram),.Z = Across-Track
Right

Baseline Corrected delta-B in nT rotated into geocentric spherical (east-north-up) coordinates. [DELTA_B_GEO]

Finite difference between adjacent points on spacecraft track was used to
determine along and across track unit vectors in GEO. No altitude change between
adjacent points was assumed..Baseline correction (F. Rich's MFIT procedure) is
polynomial fit every half-pass to each component of Delta-B in spacecraft
coordinates using only data from region equatorward of DMSP auroral boundary
from CEDAR Database.

Baseline Corrected delta-B in nT rotated into Modified Apex Coordinates with Reference Height 110 km. [DELTA_B_APX]

Coordinates transformed with apex-python (NCAR HAO). Reference Altitude = 110km,
see Richmond, J. Geomag. Geoelec. ,1995.Baseline correction (F. Rich's MFIT
procedure) is polynomial fit every half-pass to each component of Delta-B in
spacecraft coordinates using only data from region equatorward of DMSP auroral
boundary from CEDAR Database.

Baseline Corrected delta-B in nT in spacecraft frame. [DELTA_B_SC]

X = Geodedic nadir (down), Y = Along Spacecraft Track (ram), Z = Across-Track
Right Baseline correction (F. Rich's MFIT procedure) is polynomial fit every
half-pass to each component of Delta-B in spacecraft coordinates using only data
from region equatorward of DMSP auroral boundary from CEDAR Database.

Modified Apex Geomagnetic Latitude (Reference Height 110km) [SC_APEX_LAT]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Modified Apex Geomagnetic Longitude (Reference Height 110km) [SC_APEX_LON]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Modified Apex Geomagnic Local Time (Reference Height 110km) [SC_APEX_MLT]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Numerical code for auroral region of spacecraft location (1=Equatorial,2=Auroral,3=Polar) [AURORAL_REGION]

0 = No boundary identified, 1 = Equatorward of the auroral zone, 2 = In the
auroral zone, 3 = Polar cap

Figure of Merit for Auroral Boundary Determination [AURORAL_BOUNDARY_FOM]

Typical range 0-4. Less than 2 is suspect..See DMSP CDF user manual for full
specification of FOM computation.

Integer representing the orbit of the day, signed by hemisphere (>0 Northern, <0 Southern). [ORBIT_INDEX]

Orbit start and end determined by crossings of the Apex magnetic equator. Zero
for before first equator crossing of the day.

Unit vector in the direction of spacecraft velocity (ram) in geocentric coordintes [SC_ALONG_GEO]

This is an estimate, based on a spherical trigonometry approach using a
great-circle arc between adjacent points (see user manual).

Unit vector across the spacecraft track to the left ( orthogonal to the direction of spacecraft velocity (ram) ) in geocentric coordintes. [SC_ACROSS_GEO]

This is an estimate, based on a spherical trigonometry approach using a
great-circle arc between adjacent points (see user manual).

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DMSP-F18_SSIES-3_THERMAL-PLASMA doi:10.48322/cxc3-w323
Proper citations should include the "Accessed on date" in the form .

Description

The Special Sensors-Ions, Electrons, and Scintillation (SSIES) thermal plasma
analysis package is a suite of instruments built by the Center for Space
Sciences at the University of Texas at Dallas and flown on a number of the DMSP
satellites. SSIESS includes a Retarding Potential Analyzer (RPA), Ion Drift
meter (IDM), scintillation meter, and Langmuir probe.

Data Variable Descriptions

Vx - median filtered and smoothed ion flow in the ram direction [vx]

median filtered and smoothed ion flow in the ram direction from the fits to the
RPA curve

----> Vx quality flag [READ QUALITY FLAG Document: link below] [vxqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

----> Vx root mean square of the RPA fit [vxrms]

root mean square of the fit to the RPA curve giving an indication of the quality
of the RPA data for this sweep

Vx - original unfiltered Vx flow [vxraw]

the unfiltered Vx flow values calculated by the RPA fitting routine

Vy - ion flow in the horizontal crosstrack direction [vy]

crosstrack horizontal ion flow from IDM, positive is in the sunward direction
regardless of the orientation of the orbit, data taken in two modes: normal and
slow (see nmbpts)

----> quality flag for Vy data [READ QUALITY FLAG Document: link below] [vyqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

----> standard deviation of the Vy flow [vyrms]

standard deviation of the six Vy samples taken per second in the normal mode,
fill data in slow mode

----> roughness parameter of Vy [dmhrough]

roughness parameter of Vy defined as (delta Vy / averaged Vy)

Vz - ion flow in the vertical crosstrack direction [vz]

crosstrack vertical ion flow from IDM, positive is in the upward direction, data
taken in two modes: normal and slow (see nmbpts)

----> quality flag for Vz data [READ QUALITY FLAG Document: link below] [vzqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

----> standard deviation of the Vz flow [vzrms]

standard deviation of the six Vz samples taken per second in the normal mode,
fill data in slow mode

----> roughness parameter of Vz (delta Vz / averaged Vz) [dmvrough]

roughness parameter of Vy defined as (delta Vy / averaged Vy)

ion temperature [temp]

temperature of the ions in the plasma calculated from the fit to the RPA curve

----> Quality flag for the ion temperature [READ QUALITY FLAG Document: link below] [tempqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

electron temperature [te]

the electron temperature based on an onboard calculation of the Langmuir probe
sweep which occurs once every 4 s

Ni calculated from the RPA [dens]

Ion density of the plasma calculated from the fit to the RPA curve

----> quality flag for the ion density [READ QUALITY FLAG Document: link below] [densqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

Ni from scintillation meter [ductdens]

the average of the 24 Hz samples of the ion density by the scintillation meter,
because of its large aperture this is considered the best meaure of the ion
density

----> roughness parameter of SM density [ductdensrough]

roughness parameter of scintillation meter ion density  defined as (delta Ni/
averaged Ni)

Ni measured from the RPA at 0 volts [dens0v]

during each RPA sweep there is a point where the repeller voltage is 0 V so all
the ions reach the collector, this is the ion density based on that measurement

Ni from the IDM [dmdens]

the ion density based on the collector current in the IDM, because some or all
of the light ions are excluded this density should always be equal to or less
than the other ion densities

fractional amount of H+ ions in plasma [frach]

fractional amount of the plasma that is H+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional H+ [READ QUALITY FLAG Document: link below] [frachqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

fractional amount of He+ ions in plasma [frache]

fractional amount of the plasma that is He+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional He+ [READ QUALITY FLAG Document: link below] [frachequal]

1-good 2-fair 3-caution 4-bad 5-uncertain

fractional amount of O+ ions in plasma [fraco]

fractional amount of the plasma that is O+ based on the fitting of the RPA
curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and
negative

----> quality flag for fractional O+ [READ QUALITY FLAG Document: link below] [fracoqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

electron background monitor - high energy particle currents detected by the RPA [ebm]

once every 2 s the RPA repeller voltage is set so high that only high energy
electrons or ions reach the collector. A large current indicates high-energy
particles or photo-electron production (a sun-glint).

Overall quality flag for RPA data [READ QUALITY FLAG Document: link below] [corrpaqual]

1-good 2-fair 3-caution 4-bad 5-uncertain

flag for RPA sweep direction [READ QUALITY FLAG Document: link below] [rpainfo]

1-retarding potential increasing 2-retarding potential decreasing

geographical latitude [glat]

geographic latitude of s/c

geographic east longitude [glon]

geographic east longitude of s/c

magnetic latitude, mapped to 120 km [mlat]

magnetic latitude of field line at s/c mapped to 120 km

magnetic local time, mapped to 120 km [mlt]

magnetic local time of field line at s/c mapped to 120 km

solar zenith angle [sza]

angle between the sun-earth line and the s/c-center of earth line

altitude [alt]

altitude of the s/c above earth’s surface

[Labels on plots] magnetic latitude, mapped to 120 km [mlat_tt]

magnetic latitude of field line at s/c mapped to 120 km

[Labels on plots] magnetic local time, mapped to 120 km [mlt_tt]

magnetic local time of field line at s/c mapped to 120 km

[Labels on plots] geographical latitude [glat_tt]

geographic latitude of s/c

[Labels on plots] geographic east longitude [glon_tt]

geographic east longitude of s/c

[Labels on plots] solar zenith angle [sza_tt]

angle between the sun-earth line and the s/c-center of earth line

[Labels on plots] altitude [alt_tt]

altitude of the s/c above earth’s surface

number of data points in the Vy - Vz average [nmbot]

the IDM operates in two modes: normal mode takes six horizontal and six vertical
samples per second, slow mode is for low density conditions where only one
sample is taken each second and alternates between directions

overall quality flag for the IDM data [READ QUALITY FLAG Document: link below] [idmqual]

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution
(F17) 9-caution (sun glint or high-energy particles)

spacecraft velocity [scvel]

orbital velocity of the spacecraft

potential difference between SSIES instruments and spacecraft ground [rpaground]

the DMSP spacecraft charges negative relative to the plasma ground so SSIES is
electrically insolated and driven positive relative to spacecraft ground to keep
the instrument near the plasma ground

potential of the SSIES instruments relative to the plasma ground [pot]

all the SSIES instruments are held near the plasma ground potential, nominally
about -1 V relative to the plasma, this value is calculated from the RPA curve
fit, shown as \“SC Potential\” on the plots

north component of Earths magnetic field (IGRF) [bx]

northward component of the Earths magnetic field at the spacecrafts location
calculated by the IGRF model

east component of Earths magnetic field (IGRF) [by]

eastward component of the Earths magnetic field at the spacecrafts location
calculated by the IGRF model

vertical downward component of Earths magnetic field (IGRF) [bz]

vertical downward component of the Earths magnetic field at the spacecrafts
location calculated by the IGRF model

corotation velocity of ionosphere in the ram direction [corvelx]

the ram component (x) of the corotation speed of the ionosphere at the
spacecrafts location

corotation velocity of ionosphere in the horizontal crosstrack direction [corvely]

the crosstrack horizontal component (y) of the corotation speed of the
ionosphere at the spacecrafts location

corotation velocity of ionosphere in the vertical direction [corvelz]

the crosstrack vertical component (z) of the corotation speed of the ionosphere
at the spacecrafts location, since DMSP is in a circular orbit, this value is
zero

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DMSP-F18_SSJ_PRECIPITATING-ELECTRONS-IONS doi:10.48322/34mn-w272

Description

Precipitating electrons and ions observed at nominally 850km altitude and over a
range of energies from 30 eV to 30 keV using the Special Sensor J (SSJ)
instrument.  Please contact Rob.Redmon@noaa.gov with questions and comments.
Many individuals made important contributions including: D. Hardy, E. Holeman,
F. Rich, D. Ober, G. Wilson, J. Machuzak, K. Kadinsky-Cade, J. McGarity, W.F.
Denig, K. Martin, R. Redmon, D. Knipp, L. Kilcommons.

Modification History

This is version 1, beta.

Data Variable Descriptions

Electrons 30eV-30keV: Electron counts as observed; no corrections. [ELE_COUNTS_OBS]

-----> Background electron count estimate. [ELE_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

--> Electron differential energy flux (ev/cm2/delta-eV/ster/s). [ELE_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ELE_DIFF_ENERGY_FLUX_STD

-----> Estimated uncertainty in electron differential energy flux (fractional). [ELE_DIFF_ENERGY_FLUX_STD]

--> Electron total energy flux integrated over energy (eV/cm2/ster/s). [ELE_TOTAL_ENERGY_FLUX]

 DELTA_PLUS_VAR CDF_CHAR ELE_TOTAL_ENERGY_FLUX_STD DELTA_MINUS_VAR CDF_CHAR
ELE_TOTAL_ENERGY_FLUX_STD

-----> Estimated uncertainty in electron total energy flux integrated over energy (fractional). [ELE_TOTAL_ENERGY_FLUX_STD]

--> Electron average energy (eV). [ELE_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux.  DELTA_PLUS_VAR CDF_CHAR
ELE_AVG_ENERGY_STD DELTA_MINUS_VAR CDF_CHAR ELE_AVG_ENERGY_STD

-----> Estimated uncertainty in electron average energy (fractional). [ELE_AVG_ENERGY_STD]

Ions 30eV-30keV: Ion counts as observed; no corrections. [ION_COUNTS_OBS]

-----> Background ion count estimate. [ION_COUNTS_BKG]

This instrument doesn't have a dedicated background channel. An estimate is
arrived at by running the AFRL technique forward and backward in time and
choosing the largest of these two estimates for each second and energy channel.

--> Ion differential energy flux (ev/cm2/delta-eV/ster/s). [ION_DIFF_ENERGY_FLUX]

Uncertainty represented in variable ION_DIFF_ENERGY_FLUX_STD

-----> Estimated uncertainty in ion differential energy flux (fractional). [ION_DIFF_ENERGY_FLUX_STD]

--> Ion total energy flux integrated over energy (eV/cm2/ster/s). [ION_TOTAL_ENERGY_FLUX]

 DELTA_PLUS_VAR CDF_CHAR ION_TOTAL_ENERGY_FLUX_STD DELTA_MINUS_VAR CDF_CHAR
ION_TOTAL_ENERGY_FLUX_STD

-----> Estimated uncertainty in ion total energy flux integrated over energy (fractional). [ION_TOTAL_ENERGY_FLUX_STD]

--> Ion average energy (eV). [ION_AVG_ENERGY]

Computed as: Total Energy Flux / Total Number Flux. DELTA_PLUS_VAR CDF_CHAR
ION_AVG_ENERGY_STD DELTA_MINUS_VAR CDF_CHAR ION_AVG_ENERGY_STD

-----> Estimated uncertainty in ion average energy (fractional). [ION_AVG_ENERGY_STD]

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

--> Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

--> Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

--> Distance from center of Earth in km. [SC_GEOCENTRIC_R]

--> Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

--> Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

--> Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

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DMSP-F18_SSM_MAGNETOMETER doi:10.48322/cj1v-6g43

Description

Magetic measurements taken at nominally 850km altitude using a 3-axis fluxgate
magnetometer.  Please contact Rob.Redmon@noaa.gov or
liam.kilcommons@colorado.edu with questions and comments. Many individuals made
important contributions including: F. Rich, G. Wilson, D. Ober, R. Redmon, D.
Knipp, L. Kilcommons, P. Alken.

Modification History

This is version 1, beta.
Version 1.0.1
Apex and geocentric east-north-up coordinates added. Polynomial baseline
corrected versions of perturabtions added.
Version 1.0.2
Auroral region (from SSJ boundary identification) and orbit index added 
Version 1.0.3
Added Spacecraft Along Track Unit Vector
Switched naming convention from corrected ending in _COR to original ending in
_ORIG, so that MFIT corrected data would appear to be default. Removed any
variables that were uncorrected except for spacecraft coordinates.
Version 1.0.4
Added recomputed magnetic perturbations, i.e. recomputed the IGRF field for the
improved locations, and subtracted it from the observed total field. Added
spacecraft across track unit vector. Switch SC_APEX_LON to -180. to 180. instead
of 0.-360.

Data Variable Descriptions

Earth Centered Inertial (ECI) spacecraft location (x,y,z) in km. [SC_ECI]

Epoch is True of Date (TOD). These ECI coordinates are calculated from an SPDF
SSC Locator 1-minute ephemeris using an 8 order interpolation (Burden, R. L. and
Faires, J. D., Numerical Analysis, 5th Ed., PWS Publishing Company, Boston,
1993). Using SPDF methods, expected accuracy is on the order of a few km.

Geocentric latitude [SC_GEOCENTRIC_LAT]

Calculated using IDL Astro Library function eci2geo().

Geocentric Longitude [SC_GEOCENTRIC_LON]

Calculated using IDL Astro Library function eci2geo().

Distance from center of Earth in km. [SC_GEOCENTRIC_R]

Altitude Adjusted Corrected Geomagnetic Latitude [SC_AACGM_LAT]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Longitude [SC_AACGM_LON]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Altitude Adjusted Corrected Geomagnetic Local Time [SC_AACGM_LTIME]

Calculated using SuperDARN AACGM IDL library. Values are the result of linearly
interpolating between 2 nearest AACGM 5-year epochs.

Original measured field (x,y,z) in nT in spacecraft frame. [B_SC_OBS_ORIG]

X = Geodedic nadir (down).Y = Along Spacecraft Track (ram),.Z = Across-Track
Right .NOTE: This pertrubations in this variable have been recomputed from the
observed B-field.IGRF11 was run using this day as epoch and new, more accurate
geocentric location was rotatedinto spacecraft coordinates and removed.

delta-B (Original measured B - Modeled IGRF field) (x,y,z) in nT in spacecraft frame. [DELTA_B_SC_ORIG]

X = Geodedic nadir (down).Y = Along Spacecraft Track (ram),.Z = Across-Track
Right

Baseline Corrected delta-B in nT rotated into geocentric spherical (east-north-up) coordinates. [DELTA_B_GEO]

Finite difference between adjacent points on spacecraft track was used to
determine along and across track unit vectors in GEO. No altitude change between
adjacent points was assumed..Baseline correction (F. Rich's MFIT procedure) is
polynomial fit every half-pass to each component of Delta-B in spacecraft
coordinates using only data from region equatorward of DMSP auroral boundary
from CEDAR Database.

Baseline Corrected delta-B in nT rotated into Modified Apex Coordinates with Reference Height 110 km. [DELTA_B_APX]

Coordinates transformed with apex-python (NCAR HAO). Reference Altitude = 110km,
see Richmond, J. Geomag. Geoelec. ,1995.Baseline correction (F. Rich's MFIT
procedure) is polynomial fit every half-pass to each component of Delta-B in
spacecraft coordinates using only data from region equatorward of DMSP auroral
boundary from CEDAR Database.

Baseline Corrected delta-B in nT in spacecraft frame. [DELTA_B_SC]

X = Geodedic nadir (down), Y = Along Spacecraft Track (ram), Z = Across-Track
Right Baseline correction (F. Rich's MFIT procedure) is polynomial fit every
half-pass to each component of Delta-B in spacecraft coordinates using only data
from region equatorward of DMSP auroral boundary from CEDAR Database.

Modified Apex Geomagnetic Latitude (Reference Height 110km) [SC_APEX_LAT]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Modified Apex Geomagnetic Longitude (Reference Height 110km) [SC_APEX_LON]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Modified Apex Geomagnic Local Time (Reference Height 110km) [SC_APEX_MLT]

Calculated using apex-python, which is based on Apex Fortran code available from
CEDAR database, uses nearest year epoch.

Numerical code for auroral region of spacecraft location (1=Equatorial,2=Auroral,3=Polar) [AURORAL_REGION]

0 = No boundary identified, 1 = Equatorward of the auroral zone, 2 = In the
auroral zone, 3 = Polar cap

Figure of Merit for Auroral Boundary Determination [AURORAL_BOUNDARY_FOM]

Typical range 0-4. Less than 2 is suspect..See DMSP CDF user manual for full
specification of FOM computation.

Integer representing the orbit of the day, signed by hemisphere (>0 Northern, <0 Southern). [ORBIT_INDEX]

Orbit start and end determined by crossings of the Apex magnetic equator. Zero
for before first equator crossing of the day.

Unit vector in the direction of spacecraft velocity (ram) in geocentric coordintes [SC_ALONG_GEO]

This is an estimate, based on a spherical trigonometry approach using a
great-circle arc between adjacent points (see user manual).

Unit vector across the spacecraft track to the left ( orthogonal to the direction of spacecraft velocity (ram) ) in geocentric coordintes. [SC_ACROSS_GEO]

This is an estimate, based on a spherical trigonometry approach using a
great-circle arc between adjacent points (see user manual).

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DMSPF16_R0_SSUSI

Description

No TEXT global attribute value.

Data Variable Descriptions

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DMSPF17_R0_SSUSI

Description

No TEXT global attribute value.

Data Variable Descriptions

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DMSPF18_R0_SSUSI

Description

No TEXT global attribute value.

Data Variable Descriptions

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DMSP_R0_SSIES

Description

No TEXT global attribute value.

Data Variable Descriptions

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DMSP_R0_SSJ4

Description

No TEXT global attribute value.

Data Variable Descriptions

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DN_K0_GBAY (spase://GBO/NumericalData/DARN/GooseBay/PT2M)

Description

vlptm $Revision: 4.3

Modification History

skeleton table implemented 
new formats with all the DEPEND attrs set
ISTP KPGS Standard & Conventions version 1 implemented

Data Variable Descriptions

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DN_K0_HANK (spase://GBO/NumericalData/DARN/Hankasalmi/PT2M)

Description

vlptm $Revision: 4.5

Modification History

skeleton table implemented 
new formats with all the DEPEND attrs set
ISTP KPGS Standard & Conventions version 1 implemented

Data Variable Descriptions

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DN_K0_ICEW (spase://GBO/NumericalData/DARN/Stokkseyri/PT2M)

Description

vlptm $Revision: 4.3

Modification History

skeleton table implemented 
new formats with all the DEPEND attrs set
ISTP KPGS Standard & Conventions version 1 implemented

Data Variable Descriptions

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DN_K0_KAPU (spase://GBO/NumericalData/DARN/Kapuskasing/PT2M)

Description

vlptm $Revision: 4.3

Modification History

skeleton table implemented 
new formats with all the DEPEND attrs set
ISTP KPGS Standard & Conventions version 1 implemented

Data Variable Descriptions

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DN_K0_PACE (spase://GBO/NumericalData/DARN/HalleyBay/PT2M)

Description

vlptm version 2.42
Ref1: Satellite Experiments Simultaneous with Antarctic Measurements (SESAME) 
to be submitted to Reviews of Geophysics (copy held by GGS group at NASA)
Ref2:Baker et al.,EOS 70,p785 1989. Ref3: Greenwald et al.,Radio Sci.20,p63 1985
Info:Keith Morrison,GGS Scientist,British AntarcticSurvey,Cambridge,CB3 0ET,UK
E-mail: 19989::MORRISON

Modification History

skeleton table implemented 
new formats with all the DEPEND attrs set
ISTP KPGS Standard & Conventions version 1 implemented

Data Variable Descriptions

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DN_K0_PYKK (spase://GBO/NumericalData/DARN/Pykkvibaer/PT2M)

Description

vlptm $Revision: 4.5

Modification History

skeleton table implemented 
new formats with all the DEPEND attrs set
ISTP KPGS Standard & Conventions version 1 implemented

Data Variable Descriptions

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DN_K0_SASK (spase://GBO/NumericalData/DARN/Saskatoon/PT2M)

Description

vlptm $Revision: 4.3

Modification History

skeleton table implemented 
new formats with all the DEPEND attrs set
ISTP KPGS Standard & Conventions version 1 implemented

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G08

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G09

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G10

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G11

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G12

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G13

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G14

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G15

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G16

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G17

Description

Magnetometer high-resolution data for the GOES-8 through GOES-17, (GOES I-M,
GOES-NOP and GOES-R series of 10 spacecraft). The GOES MAG subsystem consists of
fluxgate magnetometer instruments monitoring three orthogonal components of the
geomagnetic field at geosynchronous orbit (L = 6.6) with high resolution
sampling rate (G8-15: 2 Hz and G16-17: 10 Hz). The NetCDF product files include
the magnetometer observations from the instrument(s) in several coordinate
systems, and the satellite location calculated using a standard SGP/SDP orbit
propagator. The field measurements are provided as B field vectors in the ECI
(Earth-centered inertial), EPN (earthward, poleward, normal/eastward), GSE
(geocentric solar ecliptic), GSM(geocentric solar magnetospheric) and VDH
(dipole aligned) coordinate systems. For comprehensive documentation including
caveats and usage recommendations, please consult the GOES magnetometer User's
Guide at NCEI.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G18

Description

The GOES-R spacecraft includes a pair of boom-mounted fluxgate magnetometer
instruments which operate simultaneously to obtain measurements of the
geomagnetic field. The Magnetometer Subsystem supports the following mission
objectives: 1) Map the space environment that controls charged particle dynamics
in the outer region of the magnetosphere, 2) Measure the magnitude and direction
of the Earth's ambient magnetic field in three orthogonal directions in the
geosynchronous equatorial orbit, 3) Determine general level of geomagnetic
activity, and 4) Detect magnetopause crossings, storm sudden commencements, and
substorms. The product described in this file includes the magnetometer
observations in several coordinate systems.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DN_MAGN-L2-HIRES_G19

Description

The GOES-R spacecraft includes a pair of boom-mounted fluxgate magnetometer
instruments which operate simultaneously to obtain measurements of the
geomagnetic field. The Magnetometer Subsystem supports the following mission
objectives: 1) Map the space environment that controls charged particle dynamics
in the outer region of the magnetosphere, 2) Measure the magnitude and direction
of the Earth's ambient magnetic field in three orthogonal directions in the
geosynchronous equatorial orbit, 3) Determine general level of geomagnetic
activity, and 4) Detect magnetopause crossings, storm sudden commencements, and
substorms. The product described in this file includes the magnetometer
observations in several coordinate systems.

Modification History

SPDF added to master VAR_TYPE, Mission_group, Instrument_type and use of mapping
file to map attributes to ISTP equivalents
Also need to add Logical_source, Logical_source_description, Source_name and
virtual variable Epoch and time_base variable.
Also need to add FORMAT, VAR_NOTES, LABLAXIS, LABL_PTR_1, DISPLAY_TYPE variable
attributes and values
Also added validmin and max values for the b_quality variable

Data Variable Descriptions

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DSCOVR_AT_DEF (spase://NOAA/NumericalData/DSCOVR/Ephemeris/Attitude/Definitive/PT5S)

Description

DSCOVR 3-axis stabilized definitive Attitude data file.
5 second time resolution
Convention: intrinsic rotations applied in Yaw, Pitch, Roll order
Extended Kalman Filter applied to ground based solution during normal
operations. OBC solution used during calibration maneuvers.

Modification History

08/02/2017 Initial Release

Data Variable Descriptions

S/C yaw from J2000 [J2000_Yaw]

The spacecraft yaw from J2000 coordinate system. Applied as the first intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft Z-axis
(rad)

S/C pitch from J2000 [J2000_Pitch]

The spacecraft pitch from J2000 coordinate system. Applied as the second
intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft Y-axis (rad)

S/C roll from J2000 [J2000_Roll]

The spacecraft roll from J2000 coordinate system. Applied as the third intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft X-axis
(rad)

S/C yaw from epoch-of-date GCI [GCI_Yaw]

The spacecraft yaw from epoch-of-date GCI coordinate system. Applied as the
first intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft Z-axis (rad)

S/C pitch from epoch-of-date GCI [GCI_Pitch]

The spacecraft pitch from epoch-of-date GCI coordinate system. Applied as the
second intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft Y-axis (rad)

S/C roll from epoch-of-date GCI [GCI_Roll]

The spacecraft roll from epoch-of-date GCI coordinate system. Applied as the
third intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft X-axis (rad)

S/C yaw from GSE [GSE_Yaw]

The spacecraft yaw from GSE coordinate system. Applied as the first intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft Z-axis
(rad)

S/C pitch from GSE [GSE_Pitch]

The spacecraft pitch from GSE coordinate system. Applied as the second intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft Y-axis
(rad)

S/C roll from GSE [GSE_Roll]

The spacecraft roll from GSE coordinate system. Applied as the third intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft X-axis
(rad)

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DSCOVR_AT_PRE (spase://NOAA/NumericalData/DSCOVR/Ephemeris/Attitude/Preliminary/PT10S)

Description

DSCOVR 3-axis stabilized preliminary Attitude data file.
Time resolution varies.
Convention: intrinsic rotations applied in Yaw, Pitch, Roll order
 5 point Median Filter applied to DCM matrix

Modification History

8/29/2016 - Original Implementation

Data Variable Descriptions

S/C yaw from J2000 [J2000_Yaw]

The spacecraft yaw from J2000 coordinate system. Applied as the first intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft Z-axis
(rad)

S/C pitch from J2000 [J2000_Pitch]

The spacecraft pitch from J2000 coordinate system. Applied as the second
intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft Y-axis (rad)

S/C roll from J2000 [J2000_Roll]

The spacecraft roll from J2000 coordinate system. Applied as the third intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft X-axis
(rad)

S/C yaw from epoch-of-date GCI [GCI_Yaw]

The spacecraft yaw from epoch-of-date GCI coordinate system. Applied as the
first intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft Z-axis (rad)

S/C pitch from epoch-of-date GCI [GCI_Pitch]

The spacecraft pitch from epoch-of-date GCI coordinate system. Applied as the
second intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft Y-axis (rad)

S/C roll from epoch-of-date GCI [GCI_Roll]

The spacecraft roll from epoch-of-date GCI coordinate system. Applied as the
third intrinsic rotation and describes a counter-clockwise rotation about the
spacecraft X-axis (rad)

S/C yaw from GSE [GSE_Yaw]

The spacecraft yaw from GSE coordinate system. Applied as the first intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft Z-axis
(rad)

S/C pitch from GSE [GSE_Pitch]

The spacecraft pitch from coordinate system GSE. Applied as the second intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft Y-axis
(rad)

S/C roll from GSE [GSE_Roll]

The spacecraft roll from coordinate system GSE. Applied as the third intrinsic
rotation and describes a counter-clockwise rotation about the spacecraft X-axis
(rad)

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DSCOVR_COHO1HR_MERGED_MAG

Description

COHO hourly DSCOVR data were made using DSCOVR 1-second data (DSCOVR_H0_MAG
dataset) from CDAWeb at https://cdaweb.gsfc.nasa.gov/ and heliocentric 
trajectory from HELIOWeb at https://omniweb.gsfc.nasa.gov/coho/helios/heli.html  
Additional information about DSCOVR data and COHOWEB is available at
https://cdaweb.gsfc.nasa.gov  and https://omniweb.gsfc.nasa.gov/coho/

Data Variable Descriptions

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DSCOVR_H0_MAG (spase://NOAA/NumericalData/DSCOVR/PlasMag/FluxgateMagnetometer/CDF/PT1S)

Description

DSCOVR Fluxgate Magnetometer 1-sec Definitive Data

Modification History

12/01/2016 Initial release

Data Variable Descriptions

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DSCOVR_H1_FC (spase://NOAA/NumericalData/DSCOVR/PlasMag/FaradayCup/CDF/PT1M)

Description

Best fit parameters from nonlinear fitting of a single, isotropic Maxwellian
velocity distribution function to sets of DSCOVR Faraday Cup measurements of the
solar wind thermal proton peak. 1-minute resolution data are obtained by fitting
to the 1-minute integrated distributions, comprising ~15 as-measured charged
current spectra each. Reported uncertainties are fitting uncertainties, which do
not account for so-called prior uncertainties associated with non-Maxwellian
distributions in nature or with conditions that vary on timescales faster than 1
minute. The uncertainties associated with measurement of charged flux as a
function of energy are propagated. Certain empirical corrections have been
applied.

Modification History

V01: 10-MAR-2017
V02: 24-MAR-2017
V03: 30-MAY-2017
V04: 14-JULY-2017
V05: 30-JULY-2017
V06: 23-OCT-2017

Data Variable Descriptions

Data Quality Flag: 0=good; 1=bad [DQF]

Three bit processing flag: The leading bit indicates correct energy ranging in
the instrument (0 = correct ranging, 1 = proton peak tracking loss).
Measurements acquired during proton peak tracking losses have been replaced with
the fill value. The second bit indicates whether the DSCOVR density measurement
is continuously more than three sigma from the Wind measurement for more than 45
minutes (0 = long term agreement with Wind, 1 = long term disagreement with
Wind). The trailing bit indicates whether the proton peak is well-resolved and
fit (0 = well resolved, 1 = poorly resolved or abnormal, errors may not be
accurately represented by the provided uncertainty). The best estimate proton
moments are provided regardless of the two trailing bit values. Refer to the
following table:

DQF = 0, Nominal condition
DQF = 1, Questionable data quality.
Values may be invalid.
DQF = 2, Questionable density values. Density values
differ from Wind for more than 45 minutes.
DQF = 3, Density and Spike Flagged
(rare)
DQF = 4, data FILL
DQF = 5, data FILL (rare)
DQF = 6, data FILL
(rare)
DQF = 7, data FILL (rare)

proton velocity x,y,z-component (w/o error bars) [V_GSE]

The proton solar winds' velocity in GSE coord (km/s)

proton velocity x,y,z-component (with error bars) [V_GSE_ErrorBars]

The proton solar winds' velocity in GSE coord (km/s)

Proton solar winds' most probable thermal speed. (w/o error bars) [THERMAL_SPD]

Thermal width of the velocity peak component perpendicular to the sensor axis,
which is approximately radial from the sun.

Proton solar winds' most probable thermal speed. (with error bars) [THERMAL_SPD_ErrorBars]

Thermal width of the velocity peak component perpendicular to the sensor axis,
which is approximately radial from the sun.

Scalar solar wind density. (w/o error bars) [Np]

Scalar solar wind density. (with error bars) [Np_ErrorBars]

Solar wind proton temperature (w/o error bars) [THERMAL_TEMP]

Thermal width of the velocity peak component perpendicular to the sensor axis,
which is approximately radial from the sun.

Solar wind proton temperature (with error bars) [THERMAL_TEMP_ErrorBars]

Thermal width of the velocity peak component perpendicular to the sensor axis,
which is approximately radial from the sun.

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DSCOVR_HELIO1HR_POSITION doi:10.48322/90ar-hx32
Proper citations should include the "Accessed on date" in the form .

Description

No TEXT global attribute value.

Data Variable Descriptions

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DSCOVR_ORBIT_PRE (spase://NOAA/NumericalData/DSCOVR/Ephemeris/Orbit/Preliminary/PT1M)

Description

DSCOVR Predicted Orbit data file.

Data Variable Descriptions

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DYNAMO-2_DESA_NX02A-ESA-FLUX

Description

The DYNAMO-2 Dual Electrostatic Analyzer (DESA) instrument consisted of a single
boom-mounted prototype sensor (DESA-NX-02A), and a main electronics box (MEB).
The instrument was flown primarily as an engineering test flight of the DESA
sensor and was only flown aboard the second of the two DYNAMO-2 rockets
(35.357). The instrument had a single fixed field-of-view looking up towards
space along the spin-axis of the rocket. For full details of the instrument, see
Collinson et al., (2022). The instrument was configured as a low-energy
photoelectron spectrometer.

Data Variable Descriptions

Time/energy spectrogram of raw counts of electrons from the single detector of the DESA-NX-02A sensor [DESA_NX_02A_ESA_L1A_COUNTS]

Time/energy spectrogram of Differential Energy Flux of electrons [DESA_NX_02A_ESA_L2_DEF]

Data are corrected for background counts and then converted to Differential
Energy Flux as per Collinson et al., The Geometric Factor of electrostatic
plasma analyzers, Rev. Sci. Instrum., 2012

Time/energy spectrogram of Differential Energy Flux of electrons,corrected for the potential of the spacecraft from active pulses of the DYNAMO-2 Langmuir Probe. [DESA_NX_02A_ESA_L2_DEF_SC_POT_CORRECTED]

Data are corrected for background counts and then converted to Differential
Energy Flux as per Collinson et al., The Geometric Factor of electrostatic
plasma analyzers, Rev. Sci. Instrum., 2012. Data are corrected for the
spacecraft potential according to Louiville’s theorem.

Altitude above sea level during operation of the DYNAMO-2 DESA-NX-02A instrument [DESA_NX_02A_ALTITUDE]

{Data Author: S. Martin, ADNET Systems, Inc. on contract to NASA/Goddard Space
Flight Center, steven.c.martin@nasa.gov}

Latitude during operation of the DYNAMO-2 DESA-NX-02A Instrument [DESA_NX_02A_LATITUDE]

{Data Author: S. Martin, ADNET Systems, Inc. on contract to NASA/Goddard Space
Flight Center, steven.c.martin@nasa.gov}

Geographic Longitude during operation of the DYNAMO-2 DESA-NX-02A Instrument. [DESA_NX_02A_LONGITUDE]

{Data Author: S. Martin, ADNET Systems, Inc. on contract to NASA/Goddard Space
Flight Center, steven.c.martin@nasa.gov}

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