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CDAWeb Served Heliophysics Datasets Beginning with 'P'

PIONEER10_COHO1HR_MERGED_MAG_PLASMA: Pioneer-10 merged hourly magnetic field, plasma, proton fluxes, and ephermis data - E.J. Smith (HVM) and A. Barnes (PLS) (NASA JPL/AMES)
PIONEER10_MAG_1MIN_MAGNETIC_FIELD: 1 min averaged magnetic field - Edward Smith (JPL NASA)
PIONEER11_COHO1HR_MERGED_MAG_PLASMA: Pioner-11 merged hourly magnetic field, plasma, proton fluxes, and ephermis data - E.J. Smith (HVM) and A. Barnes (PLS) (NASA JPL/AMES)
PIONEER6_R0_MAGPLASMA: Pioneer6 merged magnetic field and plasma hourly data from COHOWeb Service
PIONEER7_R0_MAGPLASMA: Pioneer7 merged magnetic field and plasma hourly data from COHOWeb Service
PIONEERVENUS_COHO1HR_MERGED_MAG_PLASMA: PioneerVenus merged hourly magnetic field, plasma and ephermis data - Dr. T. C. Russell (magnetic field), Dr. Aaron Barnes (plasma) (UCLA, NASA/Ames)
POLAR_HYDRA_MOMENTS-14SEC: Polar Fast Plasma Analyzer 13.8 second Resolution Moments - J. Scudder (U of Iowa)
PO_10MINATT_EFI: Polar Spacecraft Attitude in GSE Coordinates - Mozer (UC Berkeley)
PO_6SECEDSC_EFI: Polar Electric Field (x,y) in Despun Spacecraft Coordinates - Mozer (UC Berkeley)
PO_6SECPOTLDENS_EFI: Polar Spacecraft Potential and Inferred Plasma Density - Mozer (UC Berkeley)
PO_AT_DEF: Polar Definitive Attitude Data
PO_AT_PRE: Polar Predicted Attitude Data
PO_EJ_VIS: Polar Visible Imaging System, Earth Camera Images, processed - Louis A. Frank (The University of Iowa)
PO_H0_CAM: Ion Fluxes 1-200 keV/q @ 3-minute resolution, Polar CAMMICE - R. Friedel (Lanl)
PO_H0_HYD: Polar Fast Plasma Analyzer 13.8 second Resolution Parameters - J. Scudder (U of Iowa)
PO_H0_PWI: Polar Plasma Wave Instrument, MCA, ~1.3 sec fields - D. Gurnett (U. Iowa)
PO_H0_TID: Polar TIDE H+,O+,He+ High Time Resolution Data (before 10/01/96) - Thomas E. Moore (Goddard Space Flight Center)
PO_H0_TIM: Polar Toroidal Imaging Mass-Angle Spectrograph, High Time Resolution data - W.K. Peterson (Lockheed Martin)
PO_H0_UVI: Polar Ultraviolet Imager, High Res. - G. Parks (U. Washington)
PO_H1_PWI: Polar Plasma Wave Instrument, Step Frequency Receivers A & B, ~2 sec resolution fields - D. Gurnett (U. Iowa)
PO_H1_TID: Polar TIDE Total Ion High Time Resolution Data (after 12/7/96) - Thomas E. Moore (Goddard Space Flight Center)
PO_H1_UVI: Polar Ultraviolet Imager, High Res. - G. Parks (U. Washington)
PO_H2_PWI: Polar Plasma Wave Instrument, Low Frequency Waveform Receiver, ~0.01 sec resolution fields - D. Gurnett (U. Iowa)
PO_H2_TIM: H+, O+, He+ and He++ upflowing fluxes, from Polar TIMAS - W.K. Peterson (LASP/University of Colorado)
PO_H3_PWI: Polar Plasma Wave Instrument, Low-rate High Frequency Waveform Receiver, 16K (6-channel, ~0.00003 sec resolution) fields - D. Gurnett (U. Iowa)
PO_H4_PWI: Polar Plasma Wave Instrument, High Frequency Waveform Receiver, 2 kHz (6-channel, ~0.0002 sec resolution) fields - D. Gurnett (U. Iowa)
PO_H5_PWI: Polar Plasma Wave Instrument, High Frequency Waveform Receiver, 16 kHz/30 usec (interferometry) fields - D. Gurnett (U. Iowa)
PO_H7_PWI: Polar Plasma Wave Instrument, High Frequency Waveform Receiver, 6-channel (~1.5 usec resolution) fields - D. Gurnett (U. Iowa)
PO_H8_PWI: Polar Plasma Wave Instrument, High Frequency Waveform Receiver - D. Gurnett (U. Iowa)
PO_H9_PWI: Polar Plasma Wave Instrument, High Frequency Waveform Receiver - D. Gurnett (U. Iowa)
PO_K0_CAM: ~2.3-minute Key Parameters, CAMMICE/Polar Charge And Mass Magnetospheric Ion Composition Experiment - T. A. Fritz (Boston University)
PO_K0_CEP: CEPPAD Energetic particles & angular distribution, Key parameters - J. B.Blake (Aerospace Corp. )
PO_K0_EFI: Polar Electric Field Instrument, Key Parameters - F. Mozer (UC Berkeley)
PO_K0_GIFWALK: Links to Polar KP pre-generated survey and other plots - Polar-Wind-Geotail Ground System (NASA GSFC)
PO_K0_HYD: Polar Fast Plasma Analyzer Key Parameter - J. Scudder (U of Iowa)
PO_K0_MFE: Polar Magnetic Field,Key Parameters - C.T. Russell (UCLA)
PO_K0_PIX: Polar Ionospheric X-ray Imaging Experiment Key Parameters - D. Chenette (Lockheed)
PO_K0_PWI: Polar Plasma Wave Instrument Key Parameter - D. Gurnett (U. Iowa)
PO_K0_SPHA: Polar Spin Phase Key Parameters
PO_K0_UVI: Polar Ultraviolet Imager, Key Parameters - G. Parks (U. Washington)
PO_K0_VIS: Polar Visible Imaging System Key Parameters - Louis A. Frank (The University of Iowa)
PO_K1_TIM: Polar Toroidal Imaging Mass-Angle Spectrograph, Supplemental Key Parameters - W.K. Peterson (LASP/University of Colorado)
PO_K1_VIS: Polar Visible Imaging System Earth Camera Key Parameter - Louis A. Frank (The University of Iowa)
PO_LEVEL1_UVI: Polar UVI Level-1 Full Resolution Imager Data - G. Parks (U. Washington)
PO_OR_DEF: Polar Definitive Orbit Data
PO_OR_PRE: Polar Predicted Orbit Data
PO_PA_DEF: Polar Platform Attitude Definitive data
PO_VIS_EARTH-CAMERA-CALIBRATED: Polar Visible Imaging System (VIS) Earth Camera Images at ~4 minute cadence - Louis A. Frank (The University of Iowa)
PO_VIS_VISIBLE-IMAGER-CALIBRATED: Polar Visible Imaging System (VIS) Low Res. Camera - Louis A. Frank (The University of Iowa)

PIONEER10_COHO1HR_MERGED_MAG_PLASMA (spase://VHO/NumericalData/Pioneer10/MAGandPLS/PT1H)
Description
Pioneer10 COHOweb connection
The main science objectives for the PIONEER interplanetary mission are as 
follows:
   search for the heliospheric boundary with interstellar space; 
   study the large-scale structure of the solar wind plasma and interplanetary
magnetic field within the heliosphere;
   investigate propagation of solar and galactic energetic particles in the
heliosphere;
   measure the radial gradient, spectra, and nuclear composition of the
anomalous cosmic rays from the solar wind termination shock;
   study acceleration of energetic particles by solar flare shocks and
corotating interaction regions within the heliosphere.
PI of magnetic field data: Dr. Edward J. Smith, NASA JPL.  PI of plasma data:
Dr. Aaron Barnes, Ames Research Center, NASA;  plasma data were provided by Dr.
P. Gazis, ARC. 
For the hourly resolution records, the PIONEER_10 directory contains hourly
averages of parameters for the interplanetary  magnetic field (1972-Mar-3 (63) -
1975-Nov-17 (321)), solar wind plasma (1972-Apr-18 (109) - 1995-Sep-07 (250)),
spacecraft trajectory coordinates (1972-Mar-3 (63) - 1995-Dec-31 (365)) and
Proton Fluxes (1972-Mar-15 - 1994-Nov-18)
Time Coverage of merged files: March 3, 1972 - December 31, 1995 
Pioneer-10 data have been reprocessed to ensure a uniformity of content and
coordinate systems relative to data from other deep-space missions:
   All spacecraft trajectory data were transformed to a Heliographic Inertial
(HGI) coordinate system.
   merging of trajectory coordinates, magnetic field data, and plasma data files
into a single annual file P10_YR.DAT, where YR is the year;
   Data gaps were filled with dummy numbers for the missing hours or entire days
to make all files of equal length.  The character Ə' is used to  fill all
fields for missing data according to their format, e.g. (9999.9) for a field
with the FORTRAN format F7.1. Note that format F7.1 below really means
(1X,F6.1),etc.
 
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PIONEER10_MAG_1MIN_MAGNETIC_FIELD
Description
This data set from the Pioneer 10 Helium Vector Magnetometer (HVM) consists of
one minute averages of vector components and scalar magnitudes of the
interplanetary magnetic field. The three components (Br, Bt, Bn) are given in
the RTN coordinate system and all magnetic fields are expressed in nanotelsa
units. The scalar magnitudes (B) are averages of higher resolution scalar
magnitudes. The time tag for each one-minute interval is the midpoint of the
averaging interval in SCET-UT (Spacecraft Event Time - UT). The averages were
originally calculated over one-minute intervals in Ground Received Time, and the
midpoints have been converted to SCET-UT. The file P10_LIGHTTIME contains daily
values for the one-way light-time delay. No records are written for data gaps.
Most files cover 28 or 35 days, but there are a number of shorter files,
particularly at year boundaries. Data for the Jupiter encounter, days 329-349 of
1973, are not included. The RTN system is fixed to the sun-spacecraft line and
aligned with the solar heliographic equator. The R axis is the radial direction
to the spacecraft, the T axis is the cross product of the solar rotation axis
and the R axis, and N is the cross product of R and T.  The file P10HVM_15M.SFD
provides a detailed description of the Pioneer spacecraft, the HVM experiment,
and the data. This ASCII document is written in Standard Formatted Data Unit
(SFDU) format as part of NSSDC data set 72-012A-01I for 15-minute averaged data
covering 1972-03-03 to 1975-11-17. 
Data Set Files: P10HVMMN_FMT.txt     - this document (ASCII) P10HVM_15M.SFD     
 - SFDU metadata extract from Pioneer 10 HVM 15-min. data set Myyddd.asc        
  - 1-minute data files from Pioneer 10 HVM starting at date yyddd
P10_LIGHTTIME.asc    - data file with one-way light-time delays (ASCII) 
Related Information and Data: Further details on the spacecraft, experiment,
data sets at NSSDC, and related WWW sites can be found on the Pioneer 10/11
flight project page under  http://nssdc.gsfc.nasa.gov/space/ Hour averages of 
the interplanetary solar wind data from, and hourly heliocentric coordinates of,
Pioneer 10/11 and other interplanetary spacecraft may be also be accessed and
plotted on-line through the COHOWeb service based at the same WWW site as above.
Pioneer data on NDADS (NASA"s Data Archive and Distribution Service) may be
located on the WWW via the SPyCAT service at the above URL or an e-mail message
to ARMS (Automated Retrieval Mail System) at archives@ndadsa.gsfc.nasa.gov with
HOLDINGS" on the subject line.   
Acknowledgement: Use of these data in publications should be accompanied at
minimum by acknowledgements of the National Space Science Data Center and the
responsible Principal Investigator defined in the experiment documentation
provided here. Citation of NSSDC"s Coordinated Heliospheric Observations (COHO)
data base would also be appreciated, so that other potential users will be made
aware of this service.   
Data Set Coverage (yyyy-mm-dd): 1972-03-03 to 1975-11-17 
Data Set Contact: Joyce Wolf, NASA JPL
 
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PIONEER11_COHO1HR_MERGED_MAG_PLASMA (spase://VHO/NumericalData/Pioneer11/MAGandPLS/PT1H)
Description
Pioneer11 COHOweb connection
The main science objectives for the PIONEER interplanetary mission are as 
follows:
   search for the heliospheric boundary with interstellar space; 
   study the large-scale structure of the solar wind plasma and interplanetary
magnetic field within the heliosphere;
   investigate propagation of solar and galactic energetic particles in the
heliosphere;
   measure the radial gradient, spectra, and nuclear composition of the
anomalous cosmic rays from the solar wind termination shock;
   study acceleration of energetic particles by solar flare shocks and
corotating interaction regions within the heliosphere.
PI of magnetic field data: Dr. Edward J. Smith, NASA JPL.  PI of plasma data:
Dr. Aaron Barnes, Ames Research Center, NASA;  plasma data were provided by Dr.
P. Gazis, ARC. 
For the hourly resolution records, the PIONEER_11 directory contains hourly
averages of parameters for the interplanetary  magnetic field (1973-Apr-6 -
1992-Aug-1, solar wind plasma (1973-Apr-21  - 1992-May-30), Proton Fluxes
(1972-Mar-15 - 1994-Nov-18), and spacecraft trajectory coordinates (1973-Apr-6 
- 1992-Aug-1). 
Time Coverage of merged files: April 6, 1973 - August 1, 1992 
Pioneer-11 data have been reprocessed to ensure a uniformity of content and
coordinate systems relative to data from other deep-space missions:
   All spacecraft trajectory data were transformed to a Heliographic Inertial
(HGI) coordinate system.
   merging of trajectory coordinates, magnetic field data, and plasma data files
into a single annual file P11_YR.DAT, where YR is the year;
   Data gaps were filled with dummy numbers for the missing hours or entire days
to make all files of equal length.  The character Ə' is used to  fill all
fields for missing data according to their format, e.g. (9999.9) for a field
with the FORTRAN format F7.1. Note that format F7.1 below really means
(1X,F6.1),etc.
 
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PIONEER6_R0_MAGPLASMA
Description
Pioneer6 COHOweb connection
 
Dataset in CDAWeb
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PIONEER7_R0_MAGPLASMA
Description
Pioneer7 COHOweb connection
 
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PIONEERVENUS_COHO1HR_MERGED_MAG_PLASMA (spase://VHO/NumericalData/Pioneer_Venus/MAGandPLS/PT1H)
Description
PIONEER VENUS ORBITER (PVO) was the first orbiter mission designed to conduct a
comprehensive and long term investigation of the planet Venus.  PVO measured the
detailed structure of the upper atmosphere and ionosphere of Venus and
investigated the interaction of the solar wind magnetic field and plasma with
the venusian ionosphere. Over the years 1978-1992 PVO provided nearly continuous
measurements of the solar wind from its highly eccentric orbit around Venus.
PI of magnetic field data: Dr. T. C. Russell, UCLA.
PI of plasma data: Dr. Aaron Barnes, Ames Research Center, NASA. plasma data
were provided by Dr. P. Gazis, Ames,NASA.
For the hourly resolution records, thePVO directory contains files with hourly
averages for selected parameters of the interplanetary magnetic field
(1978-12-05 - 1988-08-07) solar wind plasma (1978-12-05 - 1992-10-08) and the
spacecraft trajectory (1978-12-05 - 1992-12-31) in RTN, and in Venus-centered
(1978-12-05 - 1988-08-07) coordinates.  These were data taken from time
intervals when the spacecraft was outside the bow shock of the venusian
ionosphere and in the solar wind.
Time Coverage of merged files: 78-12-05 - 92-12-31.
PVO data have been reprocessed to ensure a uniformity of content and coordinate
systems relative to data from other deep-space missions:
- All spacecraft trajectory data were transformed to a Heliographic Inertial
(HGI) coordinate system.
- calculation of RTN components of interplanetary magnetic field from VSO
coordinates.
- merging of trajectory coordinates, magnetic field data, and plasma data files
into a single annual file PVO_YR.ascii, where YR is the year;
- Data gaps were filled with dummy numbers for the missing hours or entire days
to make all files of equal length.  The character \Ə\' is used to fill all
fields for missing data according to their format, e.g. \' 9999.9\' for a field
with the FORTRAN format F7.1. Note that format F7.1 below really means
(1X,F6.1),etc.
The Heliographic Inertial (HGI) coordinates are Sun-centered and inertially
fixed with respect to an X-axis  directed along the intersection line of the
ecliptic and solar equatorial planes.  The solar equator plane is inclined at
7.25 degrees from the ecliptic. This direction was towards ecliptic longitude of
74.36 degrees on 1 January 1900 at 1200 UT; because of precession of the
celestial equator, this longitude increases by 1.4 degrees/century. The Z axis
is directed perpendicular and northward from the solar equator, and the Y-axis
completes the right-handed set.  This system differs from the usual heliographic
coordinates  (e.g. Carrington longitudes) which are fixed in the frame of the
rotating Sun.
The RTN system is fixed at a spacecraft (or the planet). The R axis is directed
radially away from  the Sun, the T axis is the cross product of the solar
rotation axis and the R axis, and the N axis is the cross product of R and T. 
At zero Heliographic Latitude when the spacecraft is in the solar equatorial
plane the N and solar rotation axes are parallel.
Venus Solar Orbital (VSO) coordinates are defined with respect to the orbital
plane of Venus which is tilted about two degrees from the Ecliptic.  The VSO
system is Venus-centered with the X axis towards the Sun, the Z axis northward
and perpendicular to the orbital plane, and the Y axis completing the right hand
system.
Acknowledgement: Hour averages of the interplanetary solar wind data from, and
hourly heliocentric coordinates of, PVO and other interplanetary spacecraft may
be also be accessed and plotted on-line through the COHOWeb service
http://cohoweb.gsfc.nasa.gov/
 
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POLAR_HYDRA_MOMENTS-14SEC
Description
Reference: HYDRA is a 3-Dimensional Electron and Ion Hot Plasma Instrument
for the Polar Spacecraft of the GGS Mission, J. Scudder et al., 
Space Sci. Rev., 71,459-495, Feb. 1995. http://www-st.physics.uiowa.edu  
This data set contains survey electron and proton moments for density, 
bulk velocity (GSM), temperature: parallel, perpendicular, at 
13.8-second resolution as determined (0-20keV). 
Higher quality data products may be available from the P.I.
 
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PO_10MINATT_EFI
Description
Important Warning: The data described below is meant for archival purposes.  It
should not be considered as highly accurate data.  For example, accurate data
requires a correction in the form of an offset to the Sunward component of the
electric field.  A constant offset of 1.2 mV/m has been used for all the data,
this being an approximate average value.  In fact, however, the offset varies
with time, and must be determined by analysis of the particular time of
interest.  Users of this data desiring more information should get in touch with
Dr. Forrest Mozer, at the Space Sciences Laboratory, University of California,
Berkeley.
The electric field data is at spin period time resolution. This means that there
is 1 data point about every 6 seconds. However, it should be noted that there
can be longer intervals between data points, due to missing data.  Data gaps are
not filled in.
The components of the electric field are given in a coordinate system designated
as Despun Spacecraft Coordinates , or DSC.  This is a coordinate system for a
rotating spacecraft that is in an orbit near the Earth.  DSC is defined by the
spacecraft's spin plane and spin axis. However, as the Despun part of the name
suggests, the coordinate axes do not participate of the spacecraft's rotation.
The X and Y axes are on the spacecraft's spin plane; the Z axis is along the
spacecraft's spin axis.  The positive X, Y, and Z axes form an orthogonal,
right-handed coordinate system.  The positive Z axis points in the same
direction as the spacecraft's angular momentum (or spin or attitude) vector. 
The positive X axis points in the direction on the spin plane that is closest to
the direction towards the Sun.  In other words, the positive X axis points in
the direction of the projection on the spin plane of the vector from the
spacecraft to the Sun.  The positive Y axis is determined by the requirement
that the DSC system (X, Y, Z) be an orthogonal right-handed system. It follows
that the positive Y axis points in the direction on the spin plane that is 90
degrees ahead of the positive X axis (in the sense of the spacecraft's
rotation). 
The electric field data included in these files consists of 2 electric field
components on the spin plane.  The original data used is V34L, which typically
has a time resolution of about 40 data points per second.  A least-squares spin
fit of V34L is performed, and the spin fit coefficients provide the spin plane
components of the spin period electric field. 
Time is a real double-precision quantity.  The units for the time are seconds. 
The time is time elapsed since the FAST Mission Epoch, which is May 24, 1968
(1968/05/24) at 00:00:00 UT.  Each time tag indicates the mid-point of the time
interval for the corresponding spin period.  Data gaps are not filled; each time
tag corresponds to an actual data point.  
X, Y, and Z are the 3 components of the attitude vector in the GSE coordinate
system (note that all 3 X, Y, and Z components are present, despite the X in the
file name). 
 
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PO_6SECEDSC_EFI
Description
Important Warning: The data described below is meant for archival purposes.  It
should not be considered as highly accurate data.  For example, accurate data
requires a correction in the form of an offset to the Sunward component of the
electric field.  A constant offset of 1.2 mV/m has been used for all the data,
this being an approximate average value.  In fact, however, the offset varies
with time, and must be determined by analysis of the particular time of
interest.  Users of this data desiring more information should get in touch with
Dr. Forrest Mozer, at the Space Sciences Laboratory, University of California,
Berkeley.
The electric field data is at spin period time resolution. This means that there
is 1 data point about every 6 seconds. However, it should be noted that there
can be longer intervals between data points, due to missing data.  Data gaps are
not filled in.
The components of the electric field are given in a coordinate system designated
as Despun Spacecraft Coordinates , or DSC.  This is a coordinate system for a
rotating spacecraft that is in an orbit near the Earth.  DSC is defined by the
spacecraft's spin plane and spin axis. However, as the Despun part of the name
suggests, the coordinate axes do not participate of the spacecraft's rotation.
The X and Y axes are on the spacecraft's spin plane; the Z axis is along the
spacecraft's spin axis.  The positive X, Y, and Z axes form an orthogonal,
right-handed coordinate system.  The positive Z axis points in the same
direction as the spacecraft's angular momentum (or spin or attitude) vector. 
The positive X axis points in the direction on the spin plane that is closest to
the direction towards the Sun.  In other words, the positive X axis points in
the direction of the projection on the spin plane of the vector from the
spacecraft to the Sun.  The positive Y axis is determined by the requirement
that the DSC system (X, Y, Z) be an orthogonal right-handed system. It follows
that the positive Y axis points in the direction on the spin plane that is 90
degrees ahead of the positive X axis (in the sense of the spacecraft's
rotation). 
The electric field data included in these files consists of 2 electric field
components on the spin plane.  The original data used is V34L, which typically
has a time resolution of about 40 data points per second.  A least-squares spin
fit of V34L is performed, and the spin fit coefficients provide the spin plane
components of the spin period electric field. 
Time is a real double-precision quantity.  The units for the time are seconds. 
The time is time elapsed since the FAST Mission Epoch, which is May 24, 1968
(1968/05/24) at 00:00:00 UT.  Each time tag indicates the mid-point of the time
interval for the corresponding spin period.  Data gaps are not filled; each time
tag corresponds to an actual data point.  
E_X and E_Y are the X and Y components of the electric field in the DSC
coordinate system (note that both the X and the Y component are present, despite
the X in the file name).  E_X and E_Y are real single-precision quantities. The
units for the electric field components are mV/m.  There are no missing data
values; each data point value corresponds to an actual data point. 
 
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PO_6SECPOTLDENS_EFI
Description
Important Warning: The data described below is meant for archival purposes.  It
should not be considered as highly accurate data.  For example, accurate data
requires a correction in the form of an offset to the Sunward component of the
electric field.  A constant offset of 1.2 mV/m has been used for all the data,
this being an approximate average value.  In fact, however, the offset varies
with time, and must be determined by analysis of the particular time of
interest.  Users of this data desiring more information should get in touch with
Dr. Forrest Mozer, at the Space Sciences Laboratory, University of California,
Berkeley.
The electric field data is at spin period time resolution. This means that there
is 1 data point about every 6 seconds. However, it should be noted that there
can be longer intervals between data points, due to missing data.  Data gaps are
not filled in.
The components of the electric field are given in a coordinate system designated
as Despun Spacecraft Coordinates , or DSC.  This is a coordinate system for a
rotating spacecraft that is in an orbit near the Earth.  DSC is defined by the
spacecraft's spin plane and spin axis. However, as the Despun part of the name
suggests, the coordinate axes do not participate of the spacecraft's rotation.
The X and Y axes are on the spacecraft's spin plane; the Z axis is along the
spacecraft's spin axis.  The positive X, Y, and Z axes form an orthogonal,
right-handed coordinate system.  The positive Z axis points in the same
direction as the spacecraft's angular momentum (or spin or attitude) vector. 
The positive X axis points in the direction on the spin plane that is closest to
the direction towards the Sun.  In other words, the positive X axis points in
the direction of the projection on the spin plane of the vector from the
spacecraft to the Sun.  The positive Y axis is determined by the requirement
that the DSC system (X, Y, Z) be an orthogonal right-handed system. It follows
that the positive Y axis points in the direction on the spin plane that is 90
degrees ahead of the positive X axis (in the sense of the spacecraft's
rotation). 
The electric field data included in these files consists of 2 electric field
components on the spin plane.  The original data used is V34L, which typically
has a time resolution of about 40 data points per second.  A least-squares spin
fit of V34L is performed, and the spin fit coefficients provide the spin plane
components of the spin period electric field. 
Time is a real double-precision quantity.  The units for the time are seconds. 
The time is time elapsed since the FAST Mission Epoch, which is May 24, 1968
(1968/05/24) at 00:00:00 UT.  Each time tag indicates the mid-point of the time
interval for the corresponding spin period.  Data gaps are not filled; each time
tag corresponds to an actual data point.  
The original data used is V1L, V2L, etc., which typically have a time resolution
of about 1 data point per 0.4 seconds. The spacecraft potentials come from spin
period averages of the voltages V1L, V2L, etc.  The spacecraft potential
S_C_Pot12 is defined as follows: S_C_Pot12 = (V1 + V2) / 2  The spacecraft
potential S_C_Pot34 is defined analogously.  V1, V2, etc. stand for V1L, V2L,
etc., respectively.  One additional spacecraft potential, S_C_Pot1234, is
defined as follows: S_C_Pot1234 = (S_C_Pot12 + S_C_Pot34) / 2
The plasma density n is obtained as a function of the spacecraft potential. The
function is a power function, provided by Dr. Jack Scudder (University of Iowa).
 It comes from a fit to the POLAR Hydra particle data.  The function was
determined using data for 2001/04/01. The validity of the function for dates far
from the date above has not been checked.  Values above 75 are regarded as
unphysical and re-assigned a NULL value. n will be in units of cm^(-3), i.e.,
number of charges per cubic centimeter. 
 
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PO_AT_DEF
Description
TBS
Modification History
6/13/91 - Original Implementation
9/18/91 - Modified for new attitude file format changes.  ICCR 881
2/11/92 - Used the variable name TIME and type CDF_INT4 and size 3 instead of 
EPOCH, CDF_EPOCH and 1 for the time tags.  CCR 490
6/1/92 - Added global attributes TITLE, PROJECT, DISCIPLINE, SOURCE_NAME, 
DATA_VERSION, and MODS; added variable attributes VALIDMIN, VALIDMAX, 
LABL_PTR_1, and MONOTON; added variables EPOCH and LABEL_TIME; 
changed variable name TIME to TIME_PB5.  CCR 1066
11/07/92 - use cdf variable Epoch and Time_PB5
6/8/93 - Added global attributes ADID_ref and Logical_file_id.  CCR 1092
7/5/94 - CCR ISTP 1852, updated CDHF skeleton to CDF standards - JT
9/20/94 - Added global attributes GCI_RA_ERR and GCI_DECL_ERR.  CCR 1932
11/7/94 - Merged CCR 1852 changes and corrected errors 
made in CCR 1852.  ICCR 1884
12/7/94 - Modified MODS and LABLAXIS to follow ISTP standards.  ICCR 1885
 
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PO_AT_PRE
Description
TBS
Modification History
6/13/91 - Original Implementation
9/18/91 - Modified for new attitude file format changes.  ICCR 881
2/11/92 - Used the variable name TIME and type CDF_INT4 and size 3 instead of 
EPOCH, CDF_EPOCH and 1 for the time tags.  CCR 490
6/1/92 - Added global attributes TITLE, PROJECT, DISCIPLINE, SOURCE_NAME, 
DATA_VERSION, and MODS; added variable attributes VALIDMIN, VALIDMAX, 
LABL_PTR_1, and MONOTON; added variables EPOCH and LABEL_TIME; 
changed variable name TIME to TIME_PB5.  CCR 1066
11/07/92 - use cdf variable Epoch and Time_PB5
6/8/93 - Added global attributes ADID_ref and Logical_file_id.  CCR 1092
7/5/94 - CCR ISTP 1852, updated CDHF skeleton to CDF standards - JT
9/20/94 - Added global attributes GCI_RA_ERR and GCI_DECL_ERR.  CCR 1932
11/7/94 - Merged CCR 1852 changes and corrected errors 
made in CCR 1852.  ICCR 1884
12/7/94 - Modified MODS and LABLAXIS to follow ISTP standards.  ICCR 1885
 
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PO_EJ_VIS
Description
Instrument functional description:
   The VIS is a set of three low-light-level cameras.  Two of these
   cameras share primary and some secondary optics and are designed to
   provide images of the nighttime auroral oval at visible wavelengths.
   A third camera is used to monitor the directions of the fields-of-view
   of the auroral cameras with respect to the sunlit Earth and return
   global images of the auroral oval at ultraviolet wavelengths.  The
   VIS instrumentation produces an auroral image of 256 x 256 pixels
   approximately every 24 seconds dependent on the integration time and
   filter selected.  The fields-of-view of the two nighttime auroral
   cameras are 5.6 x 6.3 degrees and 2.8 x 3.3 degrees for the low and
   medium resolution cameras, respectively.  One or more Earth camera
   images of 256 x 256 pixels are produced every five minutes, depending
   on the commanded mode.  The field-of-view of the Earth camera is
   approximately 20 x 20 degrees.
Reference:
   Frank, L. A., J. B. Sigwarth, J. D. Craven, J. P. Cravens, J. S. Dolan,
       M. R. Dvorsky, J. D. Harvey, P. K. Hardebeck, and D. Muller,
       'The Visible Imaging System (VIS) for the Polar Spacecraft',
       Space Science Review, vol. 71, pp. 297-328, 1995.
[Note to first-time users:  The first four variables are of primary
interest.  The displayable 256 x 256 image array is in variable 3.  The
correct orien- tation of a displayed image is explained in the
description of variable 3 below.]
Data set description:
   The VIS Earth camera data set comprises all Earth camera images for
the selected time period.  EJ-ER type files have images that have been
processed to remove the effects of penetrating radiation.  In addition,
the images have been flat-fielded and fixed pattern noise has been
removed.  Image pixels are median filtered with the images immediately
before and after in time.  The displayable image counts are in variable
3.  Some coordinate information is included for viewer orientation.
Coordinates are calculated for a grid of 18 x 18 points corresponding to
one pixel out of every 15 x 15 pixel block.  In addition, a rotation
matrix and a table of distortion-correcting look direction unit vectors
are provided for the purpose of calculating coordinates for every pixel.
See the description of variables 14 and 15 below.  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 19, 20, and 21 below.  A
relative intensity scale is provided by the uncompressed count table of
variable 24.  Approximate intensity levels in kiloRayleighs are given in
the intensity table of variable 25.  Information on the availability of
more precisely calibrated intensities can be found on the VIS website at
URL .http://eiger.physics.uiowa.edu/~vis/software/. 
Variable descriptions:
   1,2. Center time
       The time assigned to an image is the center time of the integration
       period within a resolution of 50 milliseconds.
   3. Image counts
       Image pixel counts range from 0 to 255.  They are stored in a two-
       dimensional 256 x 256 byte array.  Images from the Earth camera
       (sensor 0) are conventionally displayed with row 1 at the top, row 256
       at the bottom, column 1 on the left, and column 256 on the right.  The
       conventional image display for the low resolution camera (sensor 1) is
       rotated 180 degrees so that the row 1-column 1 pixel is at the lower
       right corner and the row 256-column 256 pixel is at the upper left
       corner.  When displayed in this manner, the spacecraft spin axis is
       oriented to the right in the display, the X component is defined as
       the center of the image look direction, and the Y component is the
   4. Sensor number
       0 = Earth camera,
       1 = low resolution camera,
       2 = medium resolution camera.
   5. Half integration time
       This is half the length of the integration period for the image,
       measured in milliseconds.
   6. Filter
       Twelve filters are available for visible imaging; the filter number,
       1-12, is given here.  Ultra-violet imaging is done with one filter
       only, designated here as filter number 0.  In addition, the peak
       wavelength in Angstroms is given for the selected filter.
   7. Presumed altitude of emissions
       The presumed altitude of the emissions seen in the image varies
       with the characteristics of the filter used.
   8. Platform pitch angle
       This is the platform pointing angle of rotation around the spin
       axis, measured from nadir.
 9,10. Geographic coordinates
       Geographic north latitude and east longitude are provided for the
       pixels at these image array locations: every 15th row starting
       with row 1 and ending with row 256, and every 15th column starting
       with column 1 and ending with column 256, for a total of
       18 x 18 coordinate pairs.
11,12. Spacecraft position and velocity vectors, GCI
       The spacecraft position vector and velocity vector in GCI
       coordinates are for the image center time as given in variables
       1 and 2.
  13. Spacecraft spin axis unit vector, GCI
14,15. Image-to-GCI rotation matrix and look direction vector table
       The rotation matrix may be used with the look direction vector table to
       obtain pointing vectors in GCI coordinates for each pixel.  The
       resulting vectors may be used to calculate coordinates for the observed
       positions of the pixels.  Software for this purpose is available at URL
       .http://eiger.physics.uiowa.edu/~vis/software/.  The general method 
       used is described below.
       In the image coordinate system, the X axis is the center line-of-sight
       or look direction; the Y axis is the cross product of the spin axis an
       the X axis; and the Z axis is the cross product of the X axis and the
       Y axis.  When the display orientation conventions in the variable 3
       description are applied, the low resolution camera image is rotated so
       that both Earth camera and low resolution camera images are displayed
       with Y axis pointing up and Z axis pointing toward the right.
       To obtain the coordinates of the observed position of a pixel,
       calculate the intersection of the line-of-sight with the surface
       of an oblately spheroidal Earth at the altitude given as
       variable 7.  The equation of the spheroid is
           X**2/(A+ALT)**2 + Y**2/(A+ALT)**2 + Z**2/(B+ALT)**2 = 1
           where A is the Earth radius at the equator,
                 B is the Earth radius at the pole, and
                 ALT is the given altitude.
       The line-of-sight equations are
           (X-SCX)/DX = (Y-SCY)/DY = (Z-SCZ)/DZ
           where (SCX,SCY,SCZ) is the spacecraft position vector GCI, and
                   (DX,DY,DZ)  is the look direction unit vector GCI.
       Solve the line-of-sight equations for two variables in terms
       of the third; substitute into the spheroid equation; and use the
       quadratic formula to solve for the third variable.  Select
       the solution point closer to the spacecraft.
  16. Zenith angle of center line-of-sight at presumed altitude
       This is the angle between the geocentric vector through the
       observed point, assuming the altitude given as variable 7,
       and the reverse of the image center line-of-sight vector.
  17. Sun position unit vector, GCI
  18. Solar zenith angle at observed point of center line-of-sight
       This is the angle of the sun from zenith at the observed point
       of the center line-of-sight, assuming the altitude given as
       variable 7.
  19. RGB color table
       This is the recommended color table to be used with the
       limits given in variables 20 and 21.
20,21. 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.
       assignments:
               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.
  22. Data quality flag
       The data quality word has bits set to 1 when the listed
       conditions are true.  Bit #31 is the most significant bit in the
       word, and it will not be used as a flag.  These are the bit
           bit 0 - image data frame sync error
           bit 1 - image data frame counters error
           bit 2 - image data fill frame flag.
  23. Post gap flag
       The post gap flag has these possible values:
           0 - no gap occurred immediately prior to this record,
           1 - the gap occurred because the instrument was not in
                 a mode that allowed for the production of images for the
                 selected sensor,
           2 - the gap occurred because level zero data were missing,
           3 - the gap occurred because level zero data were too
                 noisy to extract images.
  24. 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 1-256 correspond to
       compressed counts 0-255 respectively.
  25. Intensity table
       Approximate intensity levels in kiloRayleighs are given for each
       compressed count value.  Table entries 1-256 correspond to compressed
       counts 0-255 respectively.  Information on the availability of more
       precisely calibrated intensities can be found on the VIS website at
       URL .http://eiger.physics.uiowa.edu/~vis/software/. 
Supporting software:
   Supporting software is available on the VIS website at the URL
   .http://eiger.physics.uiowa.edu/~vis/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.
Modification History
Initial development
Updated TEXT section bug
Updated some variables
Added an ADID number, same as K1
changed linear validmin 0->10, validmax 255->60 to suppress dayglow - 4/12/01 -
REM
changed log validmin 0->1, validmax 255->18 to suppress dayglow - 4/12/01 - REM
 
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PO_H0_CAM
Description
No TEXT global attribute value.
Modification History
CDF Master created 3/21/03
 
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PO_H0_HYD
Description
Reference: HYDRA is a 3-Dimensional Electron and Ion Hot Plasma Instrument
for the Polar Spacecraft of the GGS Mission, J. Scudder et al., 
Space Sci. Rev., 71,459-495, Feb. 1995. http://www-st.physics.uiowa.edu  
This data set contains the differential electron and proton 
omnidirectional fluxes per unit solid angle vs energy, 
at 13.8-second resolution.  Multiply the given value by 4 pi 
to obtain the total omnidirectional differential energy flux.
There are 29 energy channels from 12.5 ev to 18.3 keV.
HYDRA is composed of two boxes, each housing 6 detectors.
A separate stepping power supply is used for each box.
The values of these steps are designed to be interlaced.
Therefore, the energies designated in this file are 
interpolated between the values of the two power supplies.
Stepping modes may also vary the number and range of steps 
during the mission.  To accommodate these changes an 
interpolation is done from the steps for a particular mode 
to the common energy values listed in ENERGY_ELE and ENERGY_ION.
Modification History
Generated March 26, 2003.
 
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PO_H0_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
Note:..The electron cyclotron frequencies are derived from the following:  Fce =
0.028 kHz*B, where B is the magnitude of the ambient magnetic field measured in
nT.  All frequencies are converted to Hz.
There are 20 MCA E frequency bands, logarithmically spaced and 14 MCA B
frequency bands, logarithmically spaced.
Modification History
Created Dec 1997
 
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PO_H0_TID (spase://VMO/NumericalData/POLAR/TIDE/H0-CDF)
Description
TIDE data for dates 28-Mar-1996 to 30-Sep-1996 are mass resolved. 
TIDE data between 01-Oct-1996 and 07-Dec-1996 are not valid.
Modification History
Skeleton table version 1 created 08/10/98.
Skeleton table version 2 created 10/16/00.
Skeleton table version 3 created 07/12/06.
 
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PO_H0_TIM (spase://VMO/NumericalData/POLAR/TIMAS/H0_PT12S)
Description
H+, O+, He+ and He++ number fluxes and statistical 
uncertainties processed by 
 the TIMAS science team.  Data acquired   
with various anglular and energy 
resolutions are combined here.  
Data Quality and other indicators are provided 
 to allow selection of high 
 resolution data (PA_status(ion)=0 and  
 Energy_status(ion)=0 )  and  
 High Quality data (Quality=0). 
 See the VAR_NOTES for the following  
 variables for more detailed information.  
Quality, PA_status, Energy_status 
Bcr, Fec, Even_odd,  
Energy_Range_ID and Spins. 
A PAPCO module exists that reads 
and displays these data and data 
From other POLAR instruments.  See
http://www.mpae.gwdg.de/mpae_projects/CCR/software/papco/papco.html and the
pointer to a description of the TIMAS PAPCO module on the TIMAS home page.
Reference:
E.G. Shelley et al., The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for
the Polar Mission, Sp. Sci. Rev, Vol 71, pp 497-530, 1995.
ftp://sierra.spasci.com/DATA/timas/TIMAS_description.html
Metadata provided by W.K. Peterson
Modification History
Version 0 December, 1997 
Version 1 July, 1998 
Version 2 December, 2000 Algorithm improved to more accurately subtract
backgrounds arising from spill over from H+ into He++ channel and other sources.
 Fill data are now inserted for limited energy and pitch angle ranges for Flux_H
Flux_O Flux_He_1 and Flux_He_2 variables. The meanging of values of the of
Quality variable have been slightly modified
 
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PO_H0_UVI
Description
References --------------------
1. M. R. Torr, et al., A far ultraviolet imager for the International
Solar-Terrestrial Physics mission, Space Sci. Rev., v71, pp329 - 383, 1995
Notes ------------------------ 
1. The UVI field of view is circular with an 8 degree full width.  The circular
image is stored in IMAGE_DATA as a rectangular array of 228 rows and 200
columns.
2.  Time information is contained in EPOCH, Time_PB5, IMG_MINUS_MSEC, and
IMG_PLUS_MSEC.  
3. Pointing information is given in GCI_LOOK_DIR, GEODETIC_LAT, and
GEODETIC_LONG. 
Modification History
v1.0 Initial Prelaunch Release 10/16/95 
v1.0 Interim Prelaunch Release 
5/8/96 Added KPGS_VERSION
3/9/97 Changed min/max valuesfor IMAGE_DATA
 
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PO_H1_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
There are 224 SFR frequency bands, logarithmically spaced.  When SFR_MODE is
Linear, the 448 linear frequency bands are mapped to 224 logarithmic bands.
Modification History
Created July 2000
 
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PO_H1_TID (spase://VMO/NumericalData/POLAR/TIDE/H1_CDF)
Description
TIDE data after 07-Dec-1996 are non-mass total ion contribution below 411 ev
Modification History
Skeleton table version 1 created 10/16/00.
Skeleton table version 2 created 07/12/06.
 
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PO_H1_UVI
Description
References --------------------
1. M. R. Torr, et al., A far ultraviolet imager for the International
Solar-Terrestrial Physics mission, Space Sci. Rev., v71, pp329 - 383, 1995
Notes ------------------------ 
1. The UVI field of view is circular with an 8 degree full width.  The circular
image is stored in IMAGE_DATA as a rectangular array of 228 rows and 200
columns.
2.  Time information is contained in EPOCH, Time_PB5, IMG_MINUS_MSEC, and
IMG_PLUS_MSEC.  
3. Pointing information is given in GCI_LOOK_DIR, GEODETIC_LAT, and
GEODETIC_LONG. 
Modification History
v1.0 Initial Prelaunch Release 10/16/95 
v1.0 Interim Prelaunch Release 
5/8/96 Added KPGS_VERSION
3/9/97 Changed min/max valuesfor IMAGE_DATA
 
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PO_H2_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
An FFT on 256 or 464 values, depending on the snapshot size, was used in
calibrating the data; i.e., perform FFT, calibrate in frequency domain, perform
inverse FFT to get calibrated time series.
Coordinate System Used:  local magnetic field-aligned, a spacecraft centered
coordinate system where Z is parallel to the local B-field determined from Polar
MFE, X points outward and lies in the plane defined by the Z-axis and the radial
vector from the earth to the spacecraft, and Y completes a right-handed system
and points eastward.  The X- and Z-axes are contained in the north-south plane.
The three orthogonal magnetic field components are given in units of nT/Sec
rather than nT because the response of the searchcoils across the passband is
not flat.  In order to obtain units of nT, the data would need to be digitally
filtered to the frequency of interest and then integrated over time. 
Integrating over the entire passband could possibly destroy the resolution of
the higher frequency components since the low frequency noise, if present, will
dominate.
Data are bandpass filtered.  The valid range of data in the frequency domain is
from 0.5 to 22.5 Hz.
Modification History
Created Oct 1999
 
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PO_H2_TIM (spase://VMO/NumericalData/POLAR/TIMAS/H2_PT12S)
Description
H+, O+, He+ and He++ upflowing fluxes and statistical .uncertainties processed
by . the TIMAS science team..These data were used as in  .preparing the
following papers .1: Peterson et al., JGR 2008 .2: Peterson et al., JGR 2006 .3:
Lennartson et al. JGR, 2004  .References:.O.W. Lennartsson et al., .Solar wind
control of Earth's H+ and O+ outflow .rates in the 15-eV to 33-keV energy
range,.J. Geophys. Res., Vol. 109, A12212 10.1029/2004JA010690, 2004..W.K.
Peterson et al., .Quiet time solar illumination effects on the fluxes and
.characteristic energies of ionospheric outflow, .J. Geophys. Res., 111, A11S05,
doi:10.1029/2005JA011596, 2006. .W.K. Peterson et al., .Solar-minimum quiet-time
ion energization and outflow in dynamic .boundary related coordinates,  .To
appear in J. Geophys. Res., 2008 .E.G. Shelley et al., The Toroidal Imaging
Mass-Angle Spectrograph (TIMAS) for the Polar Mission, Sp. Sci. Rev, Vol 71, pp
497-530, 1995...http://lasp.colorado.edu/timas/TIMAS_description.html. 
.uncertainties processed by . the TIMAS science team..These data were used as in
 .preparing the following papers .1: Peterson et al., JGR 2008 .2: Peterson et
al., JGR 2006 .3: Lennartson et al. JGR, 2004  .References:.O.W. Lennartsson et
al., .Solar wind control of Earth's H+ and O+ outflow .rates in the 15-eV to
33-keV energy range,.J. Geophys. Res., Vol. 109, A12212 10.1029/2004JA010690,
2004..W.K. Peterson et al., .Quiet time solar illumination effects on the fluxes
and .characteristic energies of ionospheric outflow, .J. Geophys. Res., 111,
A11S05, doi:10.1029/2005JA011596, 2006. .W.K. Peterson et al., .Solar-minimum
quiet-time ion energization and outflow in dynamic .boundary related
coordinates,  .To appear in J. Geophys. Res., 2008 .E.G. Shelley et al., The
Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for the Polar Mission, Sp. Sci.
Rev, Vol 71, pp 497-530,
1995...http://lasp.colorado.edu/timas/TIMAS_description.html. .uncertainties 
processed by . the TIMAS science team..These data were used as in  .preparing
the following papers .1: Peterson et al., JGR 2008 .2: Peterson et al., JGR 2006
.3: Lennartson et al. JGR, 2004  .References:.O.W. Lennartsson et al., .Solar
wind control of Earth's H+ and O+ outflow .rates in the 15-eV to 33-keV energy
range,.J. Geophys. Res., Vol. 109, A12212 10.1029/2004JA010690, 2004..W.K.
Peterson et al., .Quiet time solar illumination effects on the fluxes and
.characteristic energies of ionospheric outflow, .J. Geophys. Res., 111, A11S05,
doi:10.1029/2005JA011596, 2006. .W.K. Peterson et al., .Solar-minimum quiet-time
ion energization and outflow in dynamic .boundary related coordinates,  .To
appear in J. Geophys. Res., 2008 .E.G. Shelley et al., The Toroidal Imaging
Mass-Angle Spectrograph (TIMAS) for the Polar Mission, Sp. Sci. Rev, Vol 71, pp
497-530, 1995...http://lasp.colorado.edu/timas/TIMAS_description.html. 
.uncertainties processed by . the TIMAS science team..These data were used as in
 .preparing the following papers .1: Peterson et al., JGR 2008 .2: Peterson et
al., JGR 2006 .3: Lennartson et al. JGR, 2004  .References:.O.W. Lennartsson et
al., .Solar wind control of Earth's H+ and O+ outflow .rates in the 15-eV to
33-keV energy range,.J. Geophys. Res., Vol. 109, A12212 10.1029/2004JA010690,
2004..W.K. Peterson et al., .Quiet time solar illumination effects on the fluxes
and .characteristic energies of ionospheric outflow, .J. Geophys. Res., 111,
A11S05, doi:10.1029/2005JA011596, 2006. .W.K. Peterson et al., .Solar-minimum
quiet-time ion energization and outflow in dynamic .boundary related
coordinates,  .To appear in J. Geophys. Res., 2008 .E.G. Shelley et al., The
Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for the Polar Mission, Sp. Sci.
Rev, Vol 71, pp 497-530,
1995...http://lasp.colorado.edu/timas/TIMAS_description.html. .uncertainties 
processed by . the TIMAS science team..These data were used as in  .preparing
the following papers .1: Peterson et al., JGR 2008 .2: Peterson et al., JGR 2006
.3: Lennartson et al. JGR, 2004  .References:.O.W. Lennartsson et al., .Solar
wind control of Earth's H+ and O+ outflow .rates in the 15-eV to 33-keV energy
range,.J. Geophys. Res., Vol. 109, A12212 10.1029/2004JA010690, 2004..W.K.
Peterson et al., .Quiet time solar illumination effects on the fluxes and
.characteristic energies of ionospheric outflow, .J. Geophys. Res., 111, A11S05,
doi:10.1029/2005JA011596, 2006. .W.K. Peterson et al., .Solar-minimum quiet-time
ion energization and outflow in dynamic .boundary related coordinates,  .To
appear in J. Geophys. Res., 2008 .E.G. Shelley et al., The Toroidal Imaging
Mass-Angle Spectrograph (TIMAS) for the Polar Mission, Sp. Sci. Rev, Vol 71, pp
497-530, 1995...http://lasp.colorado.edu/timas/TIMAS_description.html.  
uncertainties processed by 
 the TIMAS science team.
These data were used as in  
preparing the following papers 
1: Peterson et al., JGR 2008 
2: Peterson et al., JGR 2006 
3: Lennartson et al. JGR, 2004  
References:
O.W. Lennartsson et al., 
Solar wind control of Earth's H+ and O+ outflow 
rates in the 15-eV to 33-keV energy range,
J. Geophys. Res., Vol. 109, A12212 10.1029/2004JA010690, 2004.
W.K. Peterson et al., 
Quiet time solar illumination effects on the fluxes and 
characteristic energies of ionospheric outflow, 
J. Geophys. Res., 111, A11S05, doi:10.1029/2005JA011596, 2006. 
W.K. Peterson et al., 
Solar-minimum quiet-time ion energization and outflow in dynamic 
boundary related coordinates,  
To appear in J. Geophys. Res., 2008 
E.G. Shelley et al., The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for
the Polar Mission, Sp. Sci. Rev, Vol 71, pp 497-530, 1995.
http://lasp.colorado.edu/timas/TIMAS_description.html
Metadata provided by W.K. Peterson
Modification History
Version 0 April, 2008..Version 1 Hopefuly not
Version 1 Hopefuly not
 
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PO_H3_PWI
Description
Effective Bandwidth is 1.5*delta_f, where delta_f depends on the size of the FFT
used to convert to the frequency domain, and delta_t.
Modification History
Created Oct 1999
 
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PO_H4_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.  donald-gurnett@.uiowa.edu
An FFT on 2048 values was used in calibrating the data; i.e., perform FFT,
calibrate in frequency domain, perform inverse FFT to get calibrated time
series.
Data are lowpass filtered so that the data are valid only up to 2 kHz.
The three orthogonal magnetic field components are given in units of nT/Sec
rather than nT because the response of the searchcoils across the passband is
not flat.  In order to obtain units of nT, the data would need to be digitally
filtered to the frequency of interest and then integrated over time. 
Integrating over the entire passband could possibly destroy the resolution of
the higher frequency components since the low frequency noise, if present, will
dominate.
Effective Bandwidth is 1.5*delta_f, where delta_f depends on the size of the FFT
used to convert to the frequency domain, and delta_t.
Modification History
Created Oct 1999
 
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PO_H5_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
An FFT on 2048 values was used in calibrating the data; i.e., perform FFT,
calibrate in frequency domain, perform inverse FFT to get calibrated time
series.
Data are lowpass filtered so that the data are valid only up to 16 kHz.
Effective Bandwidth is 1.5*delta_f, where delta_f depends on the size of the FFT
used to convert to the frequency domain, and delta_t.
Modification History
Created Oct 1999
 
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PO_H7_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
An FFT on 1024 values was used in calibrating the data; i.e., perform FFT,
calibrate in frequency domain, perform inverse FFT to get calibrated time
series.
Coordinate System Used:  local magnetic field-aligned, a spacecraft centered
coordinate system where Z is parallel to the local B-field determined from Polar
MFE, X points outward and lies in the plane defined by the Z-axis and the radial
vector from the earth to the spacecraft, and Y completes a right-handed system
and points eastward.  The X- and Z-axes are contained in the north-south plane.
Effective Bandwidth is 1.5*delta_f, where delta_f depends on the size of the FFT
used to convert to the frequency domain, and delta_t.
This data comes is in snapshots of 31816 points per channel, every 9.2 seconds,
where the duration of each snapshot is 0.045 seconds.  Since Epoch time is in
milliseconds, the times for the data points will not be unique unless the
Delta_T in milliseconds is added to the Epoch time for the snapshot.
The data in this file will be in sets of 31744 (31*1024) points per channel
because the FFT size does not come out even within the number of points per
snapshot.  To obtain the time for each point in the snapshot, increment each
Epoch time after the first with Delta_T (in ms).
Modification History
New versioned v04 data files were delivered to SPDF starting 2012/12/20
 
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PO_H8_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
An FFT on 1024 values was used in calibrating the data; i.e., perform FFT,
calibrate in frequency domain, perform inverse FFT to get calibrated time
series.
Effective Bandwidth is 1.5*delta_f, where delta_f depends on the size of the FFT
used to convert to the frequency domain, and delta_t.
Coordinate system used:  antenna coordinate system, where the u-axis is offset
by -45 degrees from the spacecraft x-axis, the v-axis is offset by -45 degrees
from the spacecraft y-axis, and the z-axis is identical to the spacecraft
z-axis.
This data comes in snapshots of 190902 points distributed among 2 to 6 channels
every 9.2 seconds, where the duration of the snapshot is 0.045 seconds.  Since
Epoch time is in milliseconds, the times for the data points will not be unique
unless the Delta_T (in milliseconds) is added to  the Epoch time for the
snapshot.
Modification History
Created Dec 2003
 
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PO_H9_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
An FFT on 1992 values was used in calibrating the data; i.e., perform FFT,
calibrate in frequency domain, perform inverse FFT to get calibrated time
series.
Effective Bandwidth is 1.5*delta_f, where delta_f depends on the size of the FFT
used to convert to the frequency domain, and delta_t.
Coordinate system used:  antenna coordinate system, where the u-axis is offset
by -45 degrees from the spacecraft x-axis, the v-axis is offset by -45 degrees
from the spacecraft y-axis, and the z-axis is identical to the spacecraft
z-axis.
This data comes in snapshots of 1992 or 3984 points every 0.064 seconds. 
Duration of a snapshot is less when the instrument is in duty cycle modes. 
Since Epoch time is in milliseconds, the times for the data points will not be
unique unless the fmsec (fraction of milliseconds) is appended to the Epoch0
time for that point.
The frequency filters used for the wideband receiver have a range that limits
the calibration.  The following table specifies the range of frequencies for
which the calibration is certified.  Outside this range the amplitude values may
be in error and should not be used.  (Translation, Filter, Freq Range) (0 kHz,
90 kHz, 7.5 kHz-90.0 kHz) (125 kHz, 90 kHz, 131.9 kHz-214.8 kHz) (250 kHz, 90
kHz, 254.3 kHz-341.2 kHz) (500 kHz, 90 kHz, 504.79 kHz-591.1 kHz) (0 kHz, 10
kHz, 0.035 kHz-11.64 kHz) (0 kHz, 22 kHz, 0.065 kHz-21.59 kHz) (0 kHz, 1-3 kHz,
1.0 kHz-3.0 kHz) (0 kHz, 3-6 kHz, 3.0 kHz-6.0 kHz) 
Modification History
Created Dec 2003
 
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PO_K0_CAM
Description
This data set contains 96-second averaged counting rates for H+, He++, (O+, O++
together), (O>2+), all from the MICS part of the instrument, with a +/- 1 degree
field of view perpendicular to the spin axis, segmented into bins of size 1/32
of a spin.
T.A. Fritz et.al, CAMMICE:The POLAR CAMMICE instruments
It also contains 96-second averaged counting rates from two proton channels
(0.5-1.7 MeV and 1.7-5.8 MeV), two He channels (1.4-4.3 MeV and 4.3-9.6 MeV),
and six CNO channels (5-10, 6-11, 7-13, 17-92, 18-92, 21-92 MeV), from the HIT
part of the instrument, with a +/- 6 degree field of view perpendicular to the
spin axis, segmented into bins  
of 1/32 of a spin.
A. Fritz et.al, CAMMICE:The POLAR CAMMICE instruments
Modification History
This is the 1st version, generated on 17 November 1995.
 
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PO_K0_CEP
Description
Data: 96 second averages
J. B. Blake et.al, Comprehensive Energetic Particle & Pitch Angle Distribution
Modification History
This is the 1st version.
 
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PO_K0_EFI
Description
Reference: DATA FORMAT CONTROL DOCUMENT (DFCD) BETWEEN THE 
INTERNATIONAL SOLAR-TERRESTRIAL PHYSICS (ISTP) PROGRAM 
INFORMATION PROCESSING DIVISION (IPD) GROUND DATA PROCESSING 
SYSTEM AND THE ISTP MISSION INVESTIGATORS SEPTEMBER 1993 Pages 3-57 through
3-60.
GGS Instrument papers (DRAFT)December 1992 pages B.2.1 thru B.2.14 inclusive.
The Polar Electric Field Instrument KPS will record data from two sets of
Langmuir probes.
The first set V12, are 130m apart, the second set V34, are 100m apart.
Modification History
Avoid B algorithm was added to the ground spinfits calculations in version 4.0.
Version 4.1: Update of Berkeley Modules.
 
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PO_K0_GIFWALK
Description
Pre-generated PWG plots
 
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PO_K0_HYD
Description
Reference: HYDRA is a 3-Dimensional Electron and Ion Hot  plasma Instrument for
the Polar Spacecraft of the GGS Mission, J. Scudder et al., Space Sci. Rev., 71,
459-495, Feb. 1995.
This data set contains the electron density and average energy, and the maximum
and minimum Debye energies, at 1-minute resolution.
J. Scudder, et.al, Space Sci. Rev., 71, 459-495, 1995,
http://www-st.physics.uiowa.edu
J. Scudder, et.al, Space Sci. Rev., 71, 459-495, 1995,
http://www-st.physics.uiowa.edu
Modification History
Created Feb. 10, 1997
3/23/97: Corrected attribute errors
 
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PO_K0_MFE
Description
Data: 0.92 minute and6 second averages
Modification History
version 1.0 Jan 93 Test. Modified by JT on Nov. 30, 1995Modified by XL on Feb.
18, 1997
 
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PO_K0_PIX
Description
INSTRUMENT DESCRIPTION:              
The PIXIE instrument remotely images 
bremsstrahlung X-rays which are 
emitted from the earth's atmosphere. 
PIXIE measures the bremsstrahlung 
X-ray flux in two spatial dimensions 
and as a function of energy from 
2 keV to 60 keV in 64 energy 
channels.  The spatial 
resolution and sensitivity of the 
instrument are a function of orbital 
altitude.  Sensitivity is optimized 
by the use of a variable 
configuration of the instrument's 
adjustable aperture plate.    
Continuous imagery will be provided, 
since PIXIE is mounted on the 
despun platform.  Each X-ray photon 
is identified individually by the 
time and location at which it is 
detected within the focal plane.
INSTRUMENT REFERENCES:               
1.  Instrument Description Document 
for the Polar Ionospheric X-ray 
Imaging Experiment (PIXIE) on the 
ISTP/GGS POLAR Satellite (submitted 
to Project as a PIXIE deliverable). 
Document number LMSC F254274 
(Lockheed Space and Missiles Co.) 
2.  McKenzie, D. L., D. J. Gorney, 
and W. L. Imhof, Auroral X-ray 
Imaging from High- and Low-Earth 
Orbit, Proc. SPIE, 1745, 39, 1992. 
3.  McKenzie, D. L., D. J. Gorney, 
and W. L. Imhof, Auroral X-ray 
Imaging from High- and Low-Earth 
Orbit, Opt. Eng. (to be published in 
the February 1994 issue). 
4.  Imhof, W. L., et al., The Polar 
Ionospheric X-ray Imaging Experiment 
(PIXIE), Space Science Reviews (to 
be published as part of a special 
issue on the GGS instruments). 
KEY PARAMETERS DESCRIPTION:          
The Primary Key Parameter data 
consists of two 64x64 pixel X-ray 
image arrays and two Mean Intensity 
measures. The images and intensities 
are associated with two variable 
integrated energy channel ranges.  
The Secondary Key Parameter data 
contains information necessary to 
the appropriate interpretation of 
the images.  This information 
includes geographic and geomagnetic 
spatial registration references, 
integrated energy range definitions, 
data quality flags, and various 
mode/state indicators.  The spatial 
references include full pixel maps 
(providing the value of a particular 
coordinate, e.g., magnetic latitude, 
at each of the 4096 pixels) as well 
as simple pixel markers locating 
specific features (such as the 
geographic and geomagnetic poles).
Modification History
Unified image array has been split
into high & low energy image arrays.
VAR_NOTES attribute entries have
been included to supplement CATDESC
entries where appropriate.
 
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PO_K0_PWI
Description
Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science
Reviews, Vol. 71, pp. 597-622, 1995.GURNETT@IOWAVE.physics.uiowa.edu
Note:..The electron ion and cyclotron frequencies are derived from the
following:  Fce = 0.028 kHz*B, where B is the magnitude of the ambient magnetic
field measured in nT.  Fcp = Fce/1837 in kHz.  FcO+ = Fcp/16 in kHz.  All
frequencies in the key parameters are converted to Hz.
Since the SFR frequency steps vary with the mode, the measured SFR frequencies
will be mapped to a fixed array of 160 approximately logarithmically spaced
frequency values, 32 frequency values for each of the five SFR channels.  In the
log mode, the 64 frequency steps of the fourth and fifth frequency channels will
be mapped to 32 frequency steps each, using geometric averaging.  In the linear
mode, the 448 linearly spaced frequency steps of the five frequency channels
will be mapped to the fixed array of 160 logarithmically spaced frequency values
using a windowing technique.  The magnetic and electric field values
corresponding to each SFR frequency step will be similarly mapped to 160-point
fixed arrays corresponding to the mapped frequency array.
Modification History
Created Sept 1992, modified by JT 2/15/96
 
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PO_K0_SPHA
Description
To be supplied 
Modification History
6/4/93 - Original Implementation
6/8/94 - CCR ISTP 1852, updated CDHF skeleton to CDF standards - JT
11/10/94 - Correct errors made in ccr 1852.  ICCR 1884
 
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PO_K0_UVI (spase://VMO/NumericalData/POLAR/UVI/K0_CDF)
Description
References --------------------
1. M. R. Torr, et al., A far ultraviolet imager for the International
Solar-Terrestrial Physics mission, Space Sci. Rev., v71, pp329 - 383, 1995
Notes ------------------------ 
1. The UVI field of view is circular with an 8 degree full width.  The circular
image is stored in IMAGE_DATA as a rectangular array of 228 rows and 200
columns.
2.  Time information is contained in EPOCH, Time_PB5, IMG_MINUS_MSEC, and
IMG_PLUS_MSEC.  
3. Pointing information is given in GCI_LOOK_DIR, GEODETIC_LAT, and
GEODETIC_LONG. 
Modification History
v1.0 Initial Prelaunch Release 10/16/95 
v1.0 Interim Prelaunch Release 
5/8/96 Added KPGS_VERSION
3/9/97 Changed min/max valuesfor IMAGE_DATA
 
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PO_K0_VIS
Description
 Instrument functional description:
    The VIS is a set of three low-light-level cameras.  Two of these
    cameras share primary and some secondary optics and are designed to
    provide images of the nighttime auroral oval at visible wavelengths.
    A third camera is used to monitor the directions of the fields-of-view
    of the auroral cameras with respect to the sunlit Earth and return
    global images of the auroral oval at ultraviolet wavelengths.  The
    VIS instrumentation produces an auroral image of 256 x 256 pixels
    approximately every 24 seconds dependent on the integration time and
    filter selected.  The fields-of-view of the two nighttime auroral
    cameras are 5.6 x 6.3 degrees and 2.8 x 3.3 degrees for the low and
    medium resolution cameras, respectively.  One or more Earth camera
    images of 256 x 256 pixels are produced every five minutes, depending
    on the commanded mode.  The field-of-view of the Earth camera is
    approximately 20 x 20 degrees.
 Reference:
    Frank, L. A., J. B. Sigwarth, J. D. Craven, J. P. Cravens, J. S. Dolan,
        M. R. Dvorsky, J. D. Harvey, P. K. Hardebeck, and D. Muller,
        'The Visible Imaging System (VIS) for the Polar Spacecraft',
        Space Science Review, vol. 71, pp. 297-328, 1995.
 [Note to first-time users:  The first four variables are of primary interest.
    The displayable 256 x 256 image array is in variable 3.  The correct orien-
    tation of a displayed image is explained in the description of variable 3
    below.]
 Data set description:
         The VIS key parameter data set is a survey of auroral activity
    provided by a series of single images showing a significant area of the
    auroral zone.  The displayable image counts are in variable 3.
         Some coordinate information is included for viewer orientation.
    Coordinates are calculated for a grid of 18 x 18 points corresponding
    to one pixel out of every 15 x 15 pixel block.  In addition, a rotation
    matrix and a table of distortion-correcting look direction unit vectors
    are provided for the purpose of calculating coordinates for every pixel.
    See the description of variables 17 and 18 below.
         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
    22, 23, and 24 below.
         A relative intensity scale is provided by the uncompressed count table
    of variable 27.  Approximate intensity levels in kiloRayleighs are given in
    the intensity table of variable 28.  Information on the availability of
    more precisely calibrated intensities can be found on the VIS website at
    URL .http://eiger.physics.uiowa.edu/~vis/software/. 
 Variable descriptions:
    1,2. Center time
        The time assigned to an image is the center time of the integration
        period within a resolution of 50 milliseconds.
    3. Image counts
        Image pixel counts range from 0 to 255.  They are stored in a two-
        dimensional 256 x 256 byte array.  Images from the Earth camera
        (sensor 0) are conventionally displayed with row 1 at the top, row 256
        at the bottom, column 1 on the left, and column 256 on the right.  The
        conventional image display for the low resolution camera (sensor 1) is
        rotated 180 degrees so that the row 1-column 1 pixel is at the lower
        right corner and the row 256-column 256 pixel is at the upper left
        corner.  When displayed in this manner, the spacecraft spin axis is
        oriented to the right in the display, the X component is defined as
        the center of the image look direction, and the Y component is the
        cross product of the spin axis and the look direction.
    4. Sensor number
        0 = Earth camera,
        1 = low resolution camera,
        2 = medium resolution camera.
    5. Half integration time
        This is half the length of the integration period for the image,
        measured in milliseconds.
    6. Filter
        Twelve filters are available for visible imaging; the filter number,
        1-12, is given here.  Ultra-violet imaging is done with one filter only,
        designated here as filter number 0.  In addition, the peak wavelength
        in Angstroms is given for the selected filter.
    7. Presumed altitude of emissions
        The presumed altitude of the emissions seen in the image varies
        with the characteristics of the filter used.
    8. Field stop position
        The field stop may partially occlude the field of view of the low
        or medium resolution cameras.  The position is given in 1.5 degree
        steps.
    9. Platform pitch angle
        This is the platform pointing angle of rotation around the spin
        axis, measured from nadir.
 10,11. Mirror elevation and azimuth angles
        For the low or medium resolution camera, the two-axis mirror
        position is given in steps measured from the instrument calibration
        switches.  The boresight of the instrument is located at step 68 in
        azimuth and step 118 in elevation.
 12,13. Geographic coordinates
        Geographic north latitude and east longitude are provided for the
        pixels at these image array locations: every 15th row starting
        with row 1 and ending with row 256, and every 15th column starting
        with column 1 and ending with column 256, for a total of
        18 x 18 coordinate pairs.
 14,15. Spacecraft position and velocity vectors, GCI
        The spacecraft position vector and velocity vector in GCI
        coordinates are for the image center time as given in variables
        1 and 2.
   16. Spacecraft spin axis unit vector, GCI
 17,18. Image-to-GCI rotation matrix and look direction vector table
        The rotation matrix may be used with the look direction vector table to
        obtain pointing vectors in GCI coordinates for each pixel.  The
        resulting vectors may be used to calculate coordinates for the observed
        positions of the pixels.  Software for this purpose is available at URL
         .http://eiger.physics.uiowa.edu/~vis/software/.  The general method 
         used is described below.
        In the image coordinate system, the X axis is the center line-of-sight
        or look direction; the Y axis is the cross product of the spin axis an
        the X axis; and the Z axis is the cross product of the X axis and the
        Y axis.  When the display orientation conventions in the variable 3
        description are applied, the low resolution camera image is rotated so
        that both Earth camera and low resolution camera images are displayed
        with Y axis pointing up and Z axis pointing toward the right.
        To obtain the coordinates of the observed position of a pixel,
        calculate the intersection of the line-of-sight with the surface
        of an oblately spheroidal Earth at the altitude given as
        variable 7.  The equation of the spheroid is
            X**2/(A+ALT)**2 + Y**2/(A+ALT)**2 + Z**2/(B+ALT)**2 = 1
            where A is the Earth radius at the equator,
                  B is the Earth radius at the pole, and
                  ALT is the given altitude.
        The line-of-sight equations are
            (X-SCX)/DX = (Y-SCY)/DY = (Z-SCZ)/DZ
            where (SCX,SCY,SCZ) is the spacecraft position vector GCI, and
                    (DX,DY,DZ)  is the look direction unit vector GCI.
        Solve the line-of-sight equations for two variables in terms
        of the third; substitute into the spheroid equation; and use the
        quadratic formula to solve for the third variable.  Select
        the solution point closer to the spacecraft.
   19. Zenith angle of center line-of-sight at presumed altitude
        This is the angle between the geocentric vector through the
        observed point, assuming the altitude given as variable 7,
        and the reverse of the image center line-of-sight vector.
   20. Sun position unit vector, GCI
   21. Solar zenith angle at observed point of center line-of-sight
        This is the angle of the sun from zenith at the observed point
        of the center line-of-sight, assuming the altitude given as
        variable 7.
   22. RGB color table
        This is the recommended color table to be used with the
        limits given in variables 23 and 24.
 23,24. 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.
   25. Data quality flag
        The data quality word has bits set to 1 when the listed
        conditions are true.  Bit #31 is the most significant bit in the
        word, and it will not be used as a flag.  These are the bit
        assignments:
            bit 0 - image data frame sync error
            bit 1 - image data frame counters error
            bit 2 - image data fill frame flag.
   26. Post gap flag
        The post gap flag has these possible values:
            0 - no gap occurred immediately prior to this record,
            1 - the gap occurred because the instrument was not in
                  a mode that allowed for the production of images for the
                  selected sensor,
            2 - the gap occurred because level zero data were missing,
            3 - the gap occurred because level zero data were too
                  noisy to extract images.
   27. 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 1-256 correspond to
        compressed counts 0-255 respectively.
   28. Intensity table
        Approximate intensity levels in kiloRayleighs are given for each
        compressed count value.  Table entries 1-256 correspond to compressed
        counts 0-255 respectively.  Information on the availability of more
        precisely calibrated intensities can be found on the VIS website at
        URL .http://eiger.physics.uiowa.edu/~vis/software/. 
 Supporting software:
    Supporting software is available on the VIS website at the URL
    .http://eiger.physics.uiowa.edu/~vis/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.
Modification History
Initial development
 
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PO_K1_TIM (spase://VMO/NumericalData/POLAR/TIMAS/K1_PT96S)
Description
H+, O+, He+ and He++ number fluxes for survey  purposes only 
E.G. Shelley et al., The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for
the Polar Mission, Sp. Sci. Rev, Vol 71, pp 497-530, 1995.
ftp://sierra.spasci.com/DATA/timas/TIMAS_description.html
Metadata provided by W.K. Peterson
Modification History
Version 0 June, 2001 
 
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PO_K1_VIS
Description
 Instrument functional description:
    The VIS is a set of three low-light-level cameras.  Two of these
    cameras share primary and some secondary optics and are designed to
    provide images of the nighttime auroral oval at visible wavelengths.
    A third camera is used to monitor the directions of the fields-of-view
    of the auroral cameras with respect to the sunlit Earth and return
    global images of the auroral oval at ultraviolet wavelengths.  The
    VIS instrumentation produces an auroral image of 256 x 256 pixels
    approximately every 24 seconds dependent on the integration time and
    filter selected.  The fields-of-view of the two nighttime auroral
    cameras are 5.6 x 6.3 degrees and 2.8 x 3.3 degrees for the low and
    medium resolution cameras, respectively.  One or more Earth camera
    images of 256 x 256 pixels are produced every five minutes, depending
    on the commanded mode.  The field-of-view of the Earth camera is
    approximately 20 x 20 degrees.
 Reference:
    Frank, L. A., J. B. Sigwarth, J. D. Craven, J. P. Cravens, J. S. Dolan,
        M. R. Dvorsky, J. D. Harvey, P. K. Hardebeck, and D. Muller,
        'The Visible Imaging System (VIS) for the Polar Spacecraft',
        Space Science Review, vol. 71, pp. 297-328, 1995.
 [Note to first-time users:  The first four variables are of primary interest.
    The displayable 256 x 256 image array is in variable 3.  The correct orien-
    tation of a displayed image is explained in the description of variable 3
    below.]
 Data set description:
         The VIS Earth camera key parameter data set is a survey of global
    auroral activity providedby a series of piled images produced by the median-
    filtering of up to five consecutive images.  The displayable image counts
    are in variable 3.
         Some coordinate information is included for viewer orientation.
    Coordinates are calculated for a grid of 18 x 18 points corresponding
    to one pixel out of every 15 x 15 pixel block.  In addition, a rotation
    matrix and a table of distortion-correcting look direction unit vectors
    are provided for the purpose of calculating coordinates for every pixel.
    See the description of variables 14 and 15 below.
         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
    19, 20, and 21 below.
         A relative intensity scale is provided by the uncompressed count table
    of variable 24.  Approximate intensity levels in kiloRayleighs are given in
    the intensity table of variable 25.  Information on the availability of
    more precisely calibrated intensities can be found on the VIS website at
    URL .http://eiger.physics.uiowa.edu/~vis/software/. 
 Variable descriptions:
    1,2. Center time
        The time assigned to an image is the center time of the integration
        period within a resolution of 50 milliseconds.
    3. Image counts
        Image pixel counts range from 0 to 255.  They are stored in a two-
        dimensional 256 x 256 byte array.  Images from the Earth camera
        (sensor 0) are conventionally displayed with row 1 at the top, row 256
        at the bottom, column 1 on the left, and column 256 on the right.  The
        conventional image display for the low resolution camera (sensor 1) is
        rotated 180 degrees so that the row 1-column 1 pixel is at the lower
        right corner and the row 256-column 256 pixel is at the upper left
        corner.  When displayed in this manner, the spacecraft spin axis is
        oriented to the right in the display, the X component is defined as
        the center of the image look direction, and the Y component is the
        cross product of the spin axis and the look direction.
    4. Sensor number
        0 = Earth camera,
        1 = low resolution camera,
        2 = medium resolution camera.
    5. Half integration time
        This is half the length of the integration period for the image,
        measured in milliseconds.
    6. Filter
        Twelve filters are available for visible imaging; the filter number,
        1-12, is given here.  Ultra-violet imaging is done with one filter only,
        designated here as filter number 0.  In addition, the peak wavelength
        in Angstroms is given for the selected filter.
    7. Presumed altitude of emissions
        The presumed altitude of the emissions seen in the image varies
        with the characteristics of the filter used.
    8. Platform pitch angle
        This is the platform pointing angle of rotation around the spin
        axis, measured from nadir.
  9,10. Geographic coordinates
        Geographic north latitude and east longitude are provided for the
        pixels at these image array locations: every 15th row starting
        with row 1 and ending with row 256, and every 15th column starting
        with column 1 and ending with column 256, for a total of
        18 x 18 coordinate pairs.
 11,12. Spacecraft position and velocity vectors, GCI
        The spacecraft position vector and velocity vector in GCI
        coordinates are for the image center time as given in variables
        1 and 2.
   13. Spacecraft spin axis unit vector, GCI
 14,15. Image-to-GCI rotation matrix and look direction vector table
        The rotation matrix may be used with the look direction vector table to
        obtain pointing vectors in GCI coordinates for each pixel.  The
        resulting vectors may be used to calculate coordinates for the observed
        positions of the pixels.  Software for this purpose is available at URL
         .http://eiger.physics.uiowa.edu/~vis/software/.  The general method 
         used is described below.
        In the image coordinate system, the X axis is the center line-of-sight
        or look direction; the Y axis is the cross product of the spin axis an
        the X axis; and the Z axis is the cross product of the X axis and the
        Y axis.  When the display orientation conventions in the variable 3
        description are applied, the low resolution camera image is rotated so
        that both Earth camera and low resolution camera images are displayed
        with Y axis pointing up and Z axis pointing toward the right.
        To obtain the coordinates of the observed position of a pixel,
        calculate the intersection of the line-of-sight with the surface
        of an oblately spheroidal Earth at the altitude given as
        variable 7.  The equation of the spheroid is
            X**2/(A+ALT)**2 + Y**2/(A+ALT)**2 + Z**2/(B+ALT)**2 = 1
            where A is the Earth radius at the equator,
                  B is the Earth radius at the pole, and
                  ALT is the given altitude.
        The line-of-sight equations are
            (X-SCX)/DX = (Y-SCY)/DY = (Z-SCZ)/DZ
            where (SCX,SCY,SCZ) is the spacecraft position vector GCI, and
                    (DX,DY,DZ)  is the look direction unit vector GCI.
        Solve the line-of-sight equations for two variables in terms
        of the third; substitute into the spheroid equation; and use the
        quadratic formula to solve for the third variable.  Select
        the solution point closer to the spacecraft.
   16. Zenith angle of center line-of-sight at presumed altitude
        This is the angle between the geocentric vector through the
        observed point, assuming the altitude given as variable 7,
        and the reverse of the image center line-of-sight vector.
   17. Sun position unit vector, GCI
   18. Solar zenith angle at observed point of center line-of-sight
        This is the angle of the sun from zenith at the observed point
        of the center line-of-sight, assuming the altitude given as
        variable 7.
   19. RGB color table
        This is the recommended color table to be used with the
        limits given in variables 20 and 21.
 20,21. 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.
   22. Data quality flag
        The data quality word has bits set to 1 when the listed
        conditions are true.  Bit #31 is the most significant bit in the
        word, and it will not be used as a flag.  These are the bit
        assignments:
            bit 0 - image data frame sync error
            bit 1 - image data frame counters error
            bit 2 - image data fill frame flag.
   23. Post gap flag
        The post gap flag has these possible values:
            0 - no gap occurred immediately prior to this record,
            1 - the gap occurred because the instrument was not in
                  a mode that allowed for the production of images for the
                  selected sensor,
            2 - the gap occurred because level zero data were missing,
            3 - the gap occurred because level zero data were too
                  noisy to extract images.
   24. 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 1-256 correspond to
        compressed counts 0-255 respectively.
   25. Intensity table
        Approximate intensity levels in kiloRayleighs are given for each
        compressed count value.  Table entries 1-256 correspond to compressed
        counts 0-255 respectively.  Information on the availability of more
        precisely calibrated intensities can be found on the VIS website at
        URL .http://eiger.physics.uiowa.edu/~vis/software/. 
 Supporting software:
    Supporting software is available on the VIS website at the URL
    .http://eiger.physics.uiowa.edu/~vis/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.
Modification History
Initial development
modified linear validmin 0=>15, linear validmax 255=>50 to suppress dayglow for
UVI testing - 4/12/01 - REM
modified log validmax 255=>15 to suppress dayglow - 4/12/01 - REM
 
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PO_LEVEL1_UVI (spase://VMO/NumericalData/POLAR/UVI/L1_CDF)
Description
Primary UVI team data products
CDAWeb displayed images have time-tags shifted 51 seconds back from nominal
Epoch
This corrects that H2 Epochs are telemetry times, not centered collection time
51 seconds is an approximate, typical correction.  Exact values depend on modes
and transition status.
Modification History
Initial work at SPDF 3/20-x/xx/2001 by REM
This dataset was renamed  from po_h2_uvi and po_l1_uvi to po_level1_uvi on
5/6/2005 in CDAWeb
 
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PO_OR_DEF
Description
TBS
Modification History
Originated Monday, May 13, 1991
Modified June 13, 1991 for version 2.1
Modified October 2,1991 for new global attributes, incr sizes
Modified 11/11/91 Add sun vector, replace space id with support id
Modified 1992 Feb 11 to use the variable name TIME and type CDF_INT4 instead of 
EPOCH and CDF_EPOCH for the time tags CCR 490
Modified 6/2/92 add project, discipline, source_name, data_version, title, and 
mods to global section; add validmin, validmax, labl_ptr_1 and monoton 
attributes to some variables; put epoch time back in, rename time to 
time_pb5; add label_time to variables
Modified 11/07/92 to use Epoch and Time_PB5 variable name
Modified 6/2/93 add ADID_ref and Logical_file_id
7/5/94 - CCR ISTP 1852 updated CDHF skeleton to CDF standards - JT
9/21/94 - Added 24 new global attributes to log the ephemeris 
comparison summary report from the definitive FDF orbit file.  CCR 1932
11/7/94 - Merged CCR 1852 changes and corrected errors 
made in CCR 1852.  ICCR 1884
12/7/94 - Modified MODS to follow ISTP standards.  ICCR 1885
01/05/95 - add heliocentric coordinate system.  CCR 1889
2/28/95 - added COMMENT1 and COMMENT2 for CCR 
11/03/95 - deleted crn_space for CCR 2154 - RM
 
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PO_OR_PRE
Description
TBS
Modification History
Originated Monday, May 13, 1991
Modified June 13, 1991 for version 2.1
Modified October 2,1991 for new global attributes, incr sizes
Modified 11/11/91 Add sun vector, replace space id with support id
Modified 1992 Feb 11 to use the variable name TIME and type CDF_INT4 instead of 
EPOCH and CDF_EPOCH for the time tags CCR 490
Modified 6/2/92 add project, discipline, source_name, data_version, title, and 
mods to global section; add validmin, validmax, labl_ptr_1 and monoton 
attributes to some variables; put epoch time back in, rename time to 
time_pb5; add label_time to variables
Modified 11/07/92 to use Epoch and Time_PB5 variable name
Modified 6/2/93 add ADID_ref and Logical_file_id
7/5/94 - CCR ISTP 1852 updated CDHF skeleton to CDF standards - JT
9/21/94 - Added 24 new global attributes to log the ephemeris 
comparison summary report from the definitive FDF orbit file.  CCR 1932
11/7/94 - Merged CCR 1852 changes and corrected errors 
made in CCR 1852.  ICCR 1884
12/7/94 - Modified MODS to follow ISTP standards.  ICCR 1885
01/05/95 - add heliocentric coordinate system.  CCR 1889
2/28/95 - added COMMENT1 and COMMENT2 for CCR 
11/03/95 - deleted crn_space for CCR 2154 - RM
 
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PO_PA_DEF
Description
Based on the FDF DPA algorithm
Modification History
6/11/93 - Original Implementation
4/1/94 - Modified VALIDMIN and VALIDMAX for ORB_ROLL, 
ORB_YAW, GCI_ROLL, GCI_YAW, GSE_ROLL, GSE_YAW, GSM_ROLL, and GSM_YAW
6/7/94 - CCR ISTP 1852, updated CDHF skeleton to CDF standards - JT
11/9/94 - Correct errors made in ccr 1852.  ICCR 1884
04/04/96 - Added despun plat.offset and lock status
 
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PO_VIS_EARTH-CAMERA-CALIBRATED
Description
Instrument functional description:
The VIS is a set of three low-light-level cameras. Two of these cameras share
primary and some secondary optics and are designed to provide images of the
nighttime auroral oval at visible wavelengths. A third camera is used to monitor
the directions of the fields-of-view of the auroral cameras with respect to the
sunlit Earth and return global images of the auroral oval at ultraviolet
wavelengths. The VIS instrumentation produces an auroral image of 256 x 256
pixels approximately every 24 seconds dependent on the integration time and
filter selected.
The fields-of-view of the two nighttime auroral cameras are 5.6 x 6.3 degrees
and 2.8 x 3.3 degrees for the low and medium resolution cameras, respectively.
The medium resolution camera was never activated. One or more Earth camera
images of 256 x 256 pixels are produced every five minutes, depending on the
commanded mode. The field-of-view of the Earth camera is approximately 20 x 20
degrees.
Reference: 
Frank, L. A., J. B. Sigwarth, J. D. Craven, J. P. Cravens, J. S. Dolan, M. R.
Dvorsky, J. D. Harvey, P. K. Hardebeck, and D. Muller, 'The Visible Imaging
System (VIS) for the Polar Spacecraft', Space Science Review, vol. 71, pp.
297-328, 1995.
http://vis.physics.uiowa.edu/vis/vis_description/vis_description.htmlx
[Note to first-time users:  The first six variables are of primary interest. The
displayable 256 x 256 raw image data is in variable 3. The displayable 256 x 256
processed image datais in variable 4. The correct orientation of a displayed
image is explained in the description of variable 3 below.]
Data set description:
The VIS Earth camera data set comprises all Earth camera images for the selected
time period. The raw displayable image counts are in variable 3 while the
processed displayable image counts are in variable 4.
Full coordinate information is included for viewer orientation. 
In addition, a rotation matrix and a table of distortion-correcting look
direction unit vectors are provided for the purpose of calculating coordinates
for every pixel. See the description of variables 20 and 21 below.
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 25, 26, and 27 below.
A relative intensity scale is provided by the uncompressed count table of
variable 30. Approximate intensity levels in kiloRayleighs are given in the
intensity table of variable 31.
For detailed information on intensities, see Sensitivities_and_Intensities.txt
https://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/SENSITIVITIES_AND_INTENSITIES.TXT
Variable descriptions:
1,2. Center time
The time assigned to an image is the center time of the integration period
within a resolution of 50 milliseconds.
3. Raw (unprocessed) image counts
Image pixel counts range from 0 to 255. They are stored in a two-dimensional 256
x 256 byte array. Images from the Earth camera (sensor 0) are conventionally
displayed with row 1 at the top, row 256 at the bottom,column 1 on the left, and
column 256 on the right. The conventional image display for the low resolution
camera (sensor 1) is rotated 180 degrees so that the row 1-column 1 pixel is at
the lower right corner and the row 256-column 256 pixel is at the upper left
corner. When displayed in this manner, the spacecraft spin axis is oriented to
the right in the display, the X component is defined as the center of the image
look direction, and the Y component is the cross product of the spin axis and
the look direction.
4. Cleaned image counts
These are image pixel counts that have been calibrated using the following
routines.
For the earth camera:
Horizontal Smooth EC 4 if Modified Julian Date (MJD) > 3429 (correction required
after an event in 2005)
Horizontal Smooth EC 6 if MJD > 4307 (correction required after an event in
2007)
Subtract Cosmic Rays
Subtract Slopes (adjusts for biases across the CCD)
Remove Weave (corrects for interference from low resolution camera)
Flat Field (corrects for other characteristics of the CCD) [Note: depending on
viewing geometry, not all irregularities can be fixed completely;  in
particular, a wide diagonal stripe may still be visible]
Dayglow Subtract
Nightglow Minimum
For the low resolution camera:
Subtract Cosmic Rays
Subtract Slopes
Flat Field
Smooth Filter
The data structure is the same as the Raw image counts. See the description of
variable 3 for details.
5. Cleaned image data in kiloRayleighs.
Same data as in variable 4, only in kiloRayleighs.
6. Sensor number
0 = Earth camera
1 = low resolution camera
2 = medium resolution camera (never activated).
7. Half integration time
This is half the length of the integration period for the image, measured in
milliseconds.
8. Filter 
Twelve filters are available for visible imaging; the filter number, 1-12, is
given here. Ultra-violet imaging is done with one filter only, designated here
as filter number 0. In addition, the peak wavelength in Angstroms is given for
the selected filter.
For detailed information on filter characteristics, see
Sensitivities_and_Intensities.txt
https://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/SENSITIVITIES_AND_INTENSITIES.TXT
9. Presumed altitude of emissions
The presumed altitude of the emissions seen in the image varies with the
characteristics of the filter used.
10. Platform pitch angle
This is the platform pointing angle of rotation around the spin axis, measured
from  nadir.
11,12. Geographic coordinates
Geographic north latitude and east longitude are provided for all pixels.
13,14. Right Ascension and Declination of each pixel These values are given in
degrees.
15. Altitude along tangent to line-of-sight for each pixel.
16. Flag to indicate if each pixel is pointed at the earth.
(0/False 1/True)
17,18. Spacecraft position and velocity vectors, GCI
The spacecraft position vector and velocity vector in GCI coordinates are for
the image center time as given in variables 1 and 2.
19. Spacecraft spin axis unit vector, GCI
20,21. Image-to-GCI rotation matrix and look direction vector table
The rotation matrix may be used with the look direction vector table to obtain
pointing vectors in GCI coordinates for each pixel. The resulting vectors may be
used to calculate coordinates for the observed positions of the pixels.
The general method used is described below in Coordinate_Calculation.txt
https://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/Coordinate_Calculation.txt
22. Zenith angle of center line-of-sight at presumed altitude 
This is the angle between the geocentric vector through the observed point,
assuming the altitude given as variable 8, and the  reverse of the image center
line-of-sight vector.
23. Sun position unit vector, GCI
24. Solar zenith angle at observed point of center line-of-sight.
This is the angle of the sun from zenith at the observed point of the center
line-of-sight, assuming the altitude given as variable 8.
25. RGB color table
This is the recommended color table to be used with the limits given in
variables 26 and 27.
 26,27. 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.
28. Data quality flag 
The data quality word has bits set to 1 when the listed conditions are true. Bit
#31 is the most significant bit in the word, and it will not be used as a flag.
These are the bit assignments:
bit 0 - image data frame sync error
bit 1 - image data frame counters error
bit 2 - image data fill frame flag.
29. Post gap flag
The post gap flag has these possible values: 
0 - no gap occurred immediately prior to this record.
1 - the gap occurred because the instrument wasnot in a mode that allowed for
the production of images for the selected sensor
2 - the gap occurred because level zero data were missing
3 - the gap occurred because level zero data were too noisy to extract images.
30. 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 1-256 correspond to compressed counts 0-255 respectively.
31. Intensity table
Approximate intensity levels in kiloRayleighs are given for each compressed
count value. Table entries 1-256 correspond to compressed counts 0-255
respectively. Intensity calculation is described in
Sensitivities_and_Intensities.txt.
https://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/SENSITIVITIES_AND_INTENSITIES.TXT
Supporting software:
Supporting software is available at
http://vis.physics.uiowa.edu/vis/software/
Included is an IDL program that displays the images with the recommended color
bar, provides approximate intensities and coordinate data for each pixel, and
and includes multiple options for image manipulation.
Modification History
Initial development
 
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PO_VIS_VISIBLE-IMAGER-CALIBRATED
Description
Instrument functional description:
The VIS is a set of three low-light-level cameras. Two of these cameras share
primary and some secondary optics and are designed to provide images of the
nighttime auroral oval at visible wavelengths. A third camera is used to monitor
the directions of the fields-of-view of the auroral cameras with respect to the
sunlit Earth and return global images of the auroral oval at ultraviolet
wavelengths. The VIS instrumentation produces an auroral image of 256 x 256
pixels approximately every 24 seconds dependent on the integration time and
filter selected.
The fields-of-view of the two nighttime auroral cameras are 5.6 x 6.3 degrees
and 2.8 x 3.3 degrees for the low and medium resolution cameras, respectively.
The medium resolution camera was never activated. One or more Earth camera
images of 256 x 256 pixels are produced every five minutes, depending on the
commanded mode. The field-of-view of the Earth camera is approximately 20 x 20
degrees.
Reference: 
Frank, L. A., J. B. Sigwarth, J. D. Craven, J. P. Cravens, J. S. Dolan, M. R.
Dvorsky, J. D. Harvey, P. K. Hardebeck, and D. Muller, 'The Visible Imaging
System (VIS) for the Polar Spacecraft', Space Science Review, vol. 71, pp.
297-328, 1995.
http://vis.physics.uiowa.edu/vis/vis_description/vis_description.htmlx
[Note to first-time users:  The first six variables are of primary interest. The
displayable 256 x 256 raw image data is in variable 3. The displayable 256 x 256
processed image datais in variable 4. The correct orientation of a displayed
image is explained in the description of variable 3 below.]
Data set description:
The VIS imaging data set comprises all Earth camera and Low Resolution camera
images for the selected time period. The raw displayable image counts are in
variable 3 while the processed displayable image counts are in variable 4.
Full coordinate information is included for viewer orientation. 
In addition, a rotation matrix and a table of distortion-correcting look
direction unit vectors are provided for the purpose of calculating coordinates
for every pixel. See the description of variables 20 and 21 below.
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 25, 26, and 27 below.
A relative intensity scale is provided by the uncompressed count table of
variable 30. Approximate intensity levels in kiloRayleighs are given in the
intensity table of variable 31.
For detailed information on intensities, see Sensitivities_and_Intensities.txt
http://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/SENSITIVITIES_AND_INTENSITIES.TXT
Variable descriptions:
1,2. Center time
The time assigned to an image is the center time of the integration period
within a resolution of 50 milliseconds.
3. Raw (unprocessed) image counts
Image pixel counts range from 0 to 255. They are stored in a two-dimensional 256
x 256 byte array. Images from the Earth camera (sensor 0) are conventionally
displayed with row 1 at the top, row 256 at the bottom,column 1 on the left, and
column 256 on the right.  The conventional image display for the low resolution
camera (sensor 1) is rotated 180 degrees so that the row 1-column 1 pixel is at
the lower right corner and the row 256-column 256 pixel is at the upper left
corner. When displayed in this manner, the spacecraft spin axis is oriented to
the right in the display, the X component is defined as the center of the image
look direction, and the Y component is the cross product of the spin axis and
the look direction.
4. Cleaned image counts
These are image pixel counts that have been calibrated using the following
routines.
For the earth camera:
Horizontal Smooth EC 4 if Modified Julian Date (MJD) > 3429 (correction required
after an event in 2005)
Horizontal Smooth EC 6 if MJD > 4307 (correction required after an event in
2007)
Subtract Cosmic Rays
Subtract Slopes (adjusts for biases across the CCD)
Remove Weave (corrects for interference from low resolution camera)
Flat Field (corrects for other characteristics of the CCD) [Note: depending on
viewing geometry, not all irregularities can be fixed completely;  in
particular, a wide diagonal stripe may still be visible]
Dayglow Subtract
Nightglow Minimum
For the low resolution camera:
Subtract Cosmic Rays
Subtract Slopes
Flat Field
Smooth Filter
The data structure is the same as the Raw image counts. See the description of
variable 3 for details.
5. Cleaned image data in kiloRayleighs.
Same data as in variable 4, only in kiloRayleighs.
6. Sensor number
0 = Earth camera
1 = low resolution camera
2 = medium resolution camera (never activated).
7. Half integration time
This is half the length of the integration period for the image, measured in
milliseconds.
8. Filter 
Twelve filters are available for visible imaging; the filter number, 1-12, is
given here. Ultra-violet imaging is done with one filter only, designated here
as filter number 0. In addition, the peak wavelength in Angstroms is given for
the selected filter.
For detailed information on filter characteristics, see
Sensitivities_and_Intensities.txt
http://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/SENSITIVITIES_AND_INTENSITIES.TXT
9. Presumed altitude of emissions
The presumed altitude of the emissions seen in the image varies with the
characteristics of the filter used.
10. Field stop position
The field stop may partially occlude the field of view of the low or medium
resolution cameras.  The position is given in 1.5 degree steps.
11. Platform pitch angle
This is the platform pointing angle of rotation around the spin axis, measured
from  nadir.
12,13. Mirror elevation and azimuth angles
For the low or medium resolution camera, the two-axis mirror position is given
in steps measured from the instrument calibration switches.
The low resolution boresight is located at step 68 in azimuth and step 118 in
elevation.
14,15. Geographic coordinates
Geographic north latitude and east longitude are provided for all pixels.
16,17. Right Ascension and Declination of each pixel These values are given in
degrees.
18. Altitude along tangent to line-of-sight for each pixel.
19. Flag to indicate if each pixel is pointed at the earth.
(0/False 1/True)
20,21. Spacecraft position and velocity vectors, GCI
The spacecraft position vector and velocity vector in GCI coordinates are for
the image center time as given in variables 1 and 2.
22. Spacecraft spin axis unit vector, GCI
23,24. Image-to-GCI rotation matrix and look direction vector table
The rotation matrix may be used with the look direction vector table to obtain
pointing vectors in GCI coordinates for each pixel. The resulting vectors may be
used to calculate coordinates for the observed positions of the pixels.
The general method used is described below in Coordinate_Calculation.txt
http://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/Coordinate_Calculation.txt
25. Zenith angle of center line-of-sight at presumed altitude 
This is the angle between the geocentric vector through the observed point,
assuming the altitude given as variable 8, and the  reverse of the image center
line-of-sight vector.
26. Sun position unit vector, GCI
27. Solar zenith angle at observed point of center line-of-sight.
This is the angle of the sun from zenith at the observed point of the center
line-of-sight, assuming the altitude given as variable 8.
28. RGB color table
This is the recommended color table to be used with the limits given in
variables 26 and 27.
29,30. 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.
31. Data quality flag 
The data quality word has bits set to 1 when the listed conditions are true. Bit
#31 is the most significant bit in the word, and it will not be used as a flag.
These are the bit assignments:
bit 0 - image data frame sync error
bit 1 - image data frame counters error
bit 2 - image data fill frame flag.
32. Post gap flag
The post gap flag has these possible values: 
0 - no gap occurred immediately prior to this record.
1 - the gap occurred because the instrument wasnot in a mode that allowed for
the production of images for the selected sensor
2 - the gap occurred because level zero data were missing
3 - the gap occurred because level zero data were too noisy to extract images.
33. 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 1-256 correspond to compressed counts 0-255 respectively.
34. Intensity table
Approximate intensity levels in kiloRayleighs are given for each compressed
count value. Table entries 1-256 correspond to compressed counts 0-255
respectively. Intensity calculation is described in
Sensitivities_and_Intensities.txt.
http://cdaweb.gsfc.nasa.gov/Polar_VIS_docs/SENSITIVITIES_AND_INTENSITIES.TXT
Supporting software:
Supporting software is available at
http://vis.physics.uiowa.edu/vis/software/
Included is an IDL program that displays the images with the recommended color
bar, provides approximate intensities and coordinate data for each pixel, and
and includes multiple options for image manipulation.
Modification History
Initial development
 
Dataset in CDAWeb
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