KPL/FK Parker Solar Probe Dynamic Frame Definitions Kernel =========================================================================== This kernel contains SPICE frame definitions to support the Parker Solar Probe mission. To be consistent with conventions prior to the mission name change from Solar Probe Plus (SPP) to Parker Solar Probe (PSP) in 2017, frame names and other text IDs are prefixed with the legacy acronym, SPP. Version and Date --------------------------------------------------------------- The TEXT_KERNEL_ID stores version information of loaded project text kernels. Each entry associated with the keyword is a string that consists of four parts: the kernel name, version, entry date, and type. SPP Dynamic Frame Kernel Version: \begindata TEXT_KERNEL_ID = 'SPP_DYNAMIC_FRAMES V2.0.1 10-29-2018 FK' \begintext Version 2.0.1 -- Oct 29, 2018 -- Lillian Nguyen Corrected the target of the RTN and HERTN frames to be the spacecraft not its frame. Corrected the text describing the secondary axis of the HEEQ frame. Version 2.0.0 -- Sept 13, 2018 -- Douglas Rodgers and Lillian Nguyen Added HGDOPP, HGMAG, and HGSPEC frames; these are like HG, but rotating at different rates relative to HCI. Fixed typo in HGI text: "... whereas HGI is frozen at epoch J2000." corrected to "... whereas HCI is frozen at epoch J2000." Replaced "PSP" with "SPP" in all text IDs to be consistent with legacy naming conventions. Version 1.0.0 -- May 15, 2018 -- Lillian Nguyen Removed GSM frame and added HGI frame. Renamed the spacecraft frame to SPP_SPACECRAFT to be consistent with the definition in the May 11, 2015 release of the spacecraft frames kernel (spp_000.tf). Updated the references. Version 0.0.0 -- May 10, 2018 -- Lillian Nguyen Prototype release. References --------------------------------------------------------------- 1. NAIF SPICE `Kernel Pool Required Reading' 2. NAIF SPICE `Frames Required Reading' 3. Email from Scott Turner, received May 2, 2018, containing attachment InstrumentFrames.pptx, by Martha Kusterer dated Sept. 19, 2017 4. msgr_dyn_v600.tf, in Planetary Data System (PDS) data set MESS-E/V/H-SPICE-6-V1.0 5. stereo_rtn.tf, at ftp://sohoftp.nascom.nasa.gov/solarsoft/stereo/gen/data/spice 6. heliospheric.tf, at ftp://sohoftp.nascom.nasa.gov/solarsoft/stereo/gen/data/spice/gen 7. Email from Scott Turner received May 11, 2018 containing notes taken from the science team meeting on the same date. 8. Snodgrass, H.B., Ulrich, R.K., 1990, Rotation of Doppler features in the solar photosphere. Astrophys. J. 351, 309. doi:10.1086/168467 Contact Information --------------------------------------------------------------- Direct questions, comments, or concerns about the contents of this kernel to: Scott Turner, JHUAPL, (443)778-1693, Scott.Turner@jhuapl.edu or Lillian Nguyen, JHUAPL (443)778-5477, Lillian.Nguyen@jhuapl.edu or Douglas Rodgers, JHUAPL (443)778-4228, Douglas.Rodgers@jhuapl.edu Implementation Notes --------------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of this frame kernel must `load' the kernel normally during program initialization. Loading the kernel associates the data items with their names in a data structure called the `kernel pool'. The SPICELIB routine FURNSH loads a kernel into the pool as shown below: FORTRAN: (SPICELIB) CALL FURNSH ( frame_kernel_name ) C: (CSPICE) furnsh_c ( frame_kernel_name ); IDL: (ICY) cspice_furnsh, frame_kernel_name MATLAB: (MICE) cspice_furnsh ( frame_kernel_name ) This file was created and may be updated with a text editor or word processor. SPP Dynamic Frames --------------------------------------------------------------- This frame kernel defines a series of dynamic frames listed in [3] that support Parker Solar Probe data reduction and analysis. All of the frame names defined by this kernel are prefixed with 'SPP_' (the legacy mission name acronym as described in the leading paragraph of this file) to avoid conflict with alternative definitions not specific to the project. Further, the project-specific ID codes -96900 to -96999 have been set aside to support these dynamic frames. The following dynamic frames are defined in this kernel file: Frame Name Relative To Type NAIF ID ====================== =================== ======= ======= Earth Based Frames: ------------------ EARTH_FIXED IAU_EARTH FIXED SPP_ECLIPDATE J2000 DYNAMIC -96900 SPP_GSE J2000 DYNAMIC -96901 Mercury Based Frames: ------------------ SPP_MSO J2000 DYNAMIC -96903 Venus Based Frames: ------------------ SPP_VSO J2000 DYNAMIC -96904 Sun Based Frames: ------------------ SPP_HG J2000 DYNAMIC -96910 SPP_HCI J2000 DYNAMIC -96911 SPP_HEE J2000 DYNAMIC -96912 SPP_HEEQ J2000 DYNAMIC -96913 SPP_RTN J2000 DYNAMIC -96914 SPP_HERTN J2000 DYNAMIC -96915 SPP_HGI J2000 DYNAMIC -96916 SPP_HGDOPP J2000 DYNAMIC -96917 SPP_HGMAG J2000 DYNAMIC -96918 SPP_HGSPEC J2000 DYNAMIC -96919 Earth Based Frames --------------------------------------------------------------- These dynamic frames are used for analyzing data in a reference frame tied to the dynamics of Earth. Some of these Earth based dynamic frames reference vectors in an Earth-fixed frame. To support loading of either rotation model (IAU_EARTH or ITRF93), the following keywords control which model is used. The model is enabled by surrounding its keyword-value block with the \begindata and \begintext markers (currently IAU_EARTH). IAU_EARTH based model: \begindata TKFRAME_EARTH_FIXED_RELATIVE = 'IAU_EARTH' TKFRAME_EARTH_FIXED_SPEC = 'MATRIX' TKFRAME_EARTH_FIXED_MATRIX = ( 1 0 0 0 1 0 0 0 1 ) \begintext ITRF93 based model: TKFRAME_EARTH_FIXED_RELATIVE = 'ITRF93' TKFRAME_EARTH_FIXED_SPEC = 'MATRIX' TKFRAME_EARTH_FIXED_MATRIX = ( 1 0 0 0 1 0 0 0 1 ) Note: Using the ITRF93 frame requires supplying SPICE with sufficient binary PCK data to cover the period of interest. The IAU_EARTH frame just requires a text PCK with Earth data to be loaded. From [3] and [6]: Mean Ecliptic of Date (ECLIPDATE): All vectors are geometric: no aberration corrections are used. The X axis is the first point in Aries for the mean ecliptic of date, and the Z axis points along the ecliptic north pole. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_ECLIPDATE = -96900 FRAME_-96900_NAME = 'SPP_ECLIPDATE' FRAME_-96900_CLASS = 5 FRAME_-96900_CLASS_ID = -96900 FRAME_-96900_CENTER = 399 FRAME_-96900_RELATIVE = 'J2000' FRAME_-96900_DEF_STYLE = 'PARAMETERIZED' FRAME_-96900_FAMILY = 'MEAN_ECLIPTIC_AND_EQUINOX_OF_DATE' FRAME_-96900_PREC_MODEL = 'EARTH_IAU_1976' FRAME_-96900_OBLIQ_MODEL = 'EARTH_IAU_1980' FRAME_-96900_ROTATION_STATE = 'ROTATING' \begintext From [3] and [6]: Geocentric Solar Ecliptic (GSE) All vectors are geometric: no aberration corrections are used. The position of the Sun relative to the Earth is the primary vector: the X axis points from the Earth to the Sun. The northern surface normal to the mean ecliptic of date is the secondary vector: the Z axis is the component of this vector orthogonal to the X axis. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_GSE = -96901 FRAME_-96901_NAME = 'SPP_GSE' FRAME_-96901_CLASS = 5 FRAME_-96901_CLASS_ID = 96901 FRAME_-96901_CENTER = 399 FRAME_-96901_RELATIVE = 'J2000' FRAME_-96901_DEF_STYLE = 'PARAMETERIZED' FRAME_-96901_FAMILY = 'TWO-VECTOR' FRAME_-96901_PRI_AXIS = 'X' FRAME_-96901_PRI_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-96901_PRI_OBSERVER = 'EARTH' FRAME_-96901_PRI_TARGET = 'SUN' FRAME_-96901_PRI_ABCORR = 'NONE' FRAME_-96901_SEC_AXIS = 'Z' FRAME_-96901_SEC_VECTOR_DEF = 'CONSTANT' FRAME_-96901_SEC_FRAME = 'SPP_ECLIPDATE' FRAME_-96901_SEC_SPEC = 'RECTANGULAR' FRAME_-96901_SEC_VECTOR = ( 0, 0, 1 ) \begintext Mercury Based Frames --------------------------------------------------------------- These dynamic frames are used for analyzing data in a reference frame tied to the dynamics of Mercury. From [4]: Mercury-centric Solar Orbital (MSO): This system has its X axis pointing from the planet to the Sun, -Y points in direction of the planetary orbital velocity vector, and Z completes the right-handed system. \begindata FRAME_SPP_MSO = -96903 FRAME_-96903_NAME = 'SPP_MSO' FRAME_-96903_CLASS = 5 FRAME_-96903_CLASS_ID = -96903 FRAME_-96903_CENTER = 199 FRAME_-96903_RELATIVE = 'J2000' FRAME_-96903_DEF_STYLE = 'PARAMETERIZED' FRAME_-96903_FAMILY = 'TWO-VECTOR' FRAME_-96903_PRI_AXIS = 'X' FRAME_-96903_PRI_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-96903_PRI_OBSERVER = 'MERCURY' FRAME_-96903_PRI_TARGET = 'SUN' FRAME_-96903_PRI_ABCORR = 'NONE' FRAME_-96903_SEC_AXIS = '-Y' FRAME_-96903_SEC_VECTOR_DEF = 'OBSERVER_TARGET_VELOCITY' FRAME_-96903_SEC_OBSERVER = 'SUN' FRAME_-96903_SEC_TARGET = 'MERCURY' FRAME_-96903_SEC_FRAME = 'J2000' FRAME_-96903_SEC_ABCORR = 'NONE' \begintext Venus Based Frames --------------------------------------------------------------- These dynamic frames are used for analyzing data in a reference frame tied to the dynamics of Venus. From [3] and [4]: Venus-centric Solar Orbital (VSO): This system has its X axis pointing from the planet to the Sun, -Y points in direction of the planetary orbital velocity vector, and Z completes the right-handed system. \begindata FRAME_SPP_VSO = -96904 FRAME_-96904_NAME = 'SPP_VSO' FRAME_-96904_CLASS = 5 FRAME_-96904_CLASS_ID = -96904 FRAME_-96904_CENTER = 299 FRAME_-96904_RELATIVE = 'J2000' FRAME_-96904_DEF_STYLE = 'PARAMETERIZED' FRAME_-96904_FAMILY = 'TWO-VECTOR' FRAME_-96904_PRI_AXIS = 'X' FRAME_-96904_PRI_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-96904_PRI_OBSERVER = 'VENUS' FRAME_-96904_PRI_TARGET = 'SUN' FRAME_-96904_PRI_ABCORR = 'NONE' FRAME_-96904_SEC_AXIS = '-Y' FRAME_-96904_SEC_VECTOR_DEF = 'OBSERVER_TARGET_VELOCITY' FRAME_-96904_SEC_OBSERVER = 'SUN' FRAME_-96904_SEC_TARGET = 'VENUS' FRAME_-96904_SEC_FRAME = 'J2000' FRAME_-96904_SEC_ABCORR = 'NONE' \begintext Sun Based Frames --------------------------------------------------------------- These dynamic frames are used for analyzing data in a reference frame tied to the dynamics of the Sun. From [3]: Heliographic (HG) This is an alias for IAU_SUN, or Carrington heliographic coordinates. The Z axis is the solar rotation axis. The X axis is the intersection of the Carrington prime meridian and the heliographic equator. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HG = -96910 FRAME_-96910_NAME = 'SPP_HG' FRAME_-96910_CLASS = 4 FRAME_-96910_CLASS_ID = -96910 FRAME_-96910_CENTER = 10 TKFRAME_-96910_RELATIVE = 'IAU_SUN' TKFRAME_-96910_SPEC = 'MATRIX' TKFRAME_-96910_MATRIX = ( 1.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 1.0 ) \begintext From [3] and [6]: Heliocentric Inertial (HCI) Frame: All vectors are geometric: no aberration corrections are used. The solar rotation axis is the primary vector: the Z axis points in the solar north direction. The ascending node on the Earth ecliptic of J2000 of the solar equator forms the X axis. This is accomplished by using the +Z axis of the ecliptic of J2000 as the secondary vector and HCI +Y as the secondary axis. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HCI = -96911 FRAME_-96911_NAME = 'SPP_HCI' FRAME_-96911_CLASS = 5 FRAME_-96911_CLASS_ID = -96911 FRAME_-96911_CENTER = 10 FRAME_-96911_RELATIVE = 'J2000' FRAME_-96911_DEF_STYLE = 'PARAMETERIZED' FRAME_-96911_FAMILY = 'TWO-VECTOR' FRAME_-96911_PRI_AXIS = 'Z' FRAME_-96911_PRI_VECTOR_DEF = 'CONSTANT' FRAME_-96911_PRI_FRAME = 'IAU_SUN' FRAME_-96911_PRI_SPEC = 'RECTANGULAR' FRAME_-96911_PRI_VECTOR = ( 0, 0, 1 ) FRAME_-96911_SEC_AXIS = 'Y' FRAME_-96911_SEC_VECTOR_DEF = 'CONSTANT' FRAME_-96911_SEC_FRAME = 'ECLIPJ2000' FRAME_-96911_SEC_SPEC = 'RECTANGULAR' FRAME_-96911_SEC_VECTOR = ( 0, 0, 1 ) \begintext From [3] and [6]: Heliocentric Earth Ecliptic (HEE) Frame: All vectors are geometric: no aberration corrections are used. The position of the Earth relative to the Sun is the primary vector: the X axis points from the Sun to the Earth. The northern surface normal to the mean ecliptic of date is the secondary vector: the Z axis is the component of this vector orthogonal to the X axis. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HEE = -96912 FRAME_-96912_NAME = 'SPP_HEE' FRAME_-96912_CLASS = 5 FRAME_-96912_CLASS_ID = -96912 FRAME_-96912_CENTER = 10 FRAME_-96912_RELATIVE = 'J2000' FRAME_-96912_DEF_STYLE = 'PARAMETERIZED' FRAME_-96912_FAMILY = 'TWO-VECTOR' FRAME_-96912_PRI_AXIS = 'X' FRAME_-96912_PRI_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-96912_PRI_OBSERVER = 'SUN' FRAME_-96912_PRI_TARGET = 'EARTH' FRAME_-96912_PRI_ABCORR = 'NONE' FRAME_-96912_SEC_AXIS = 'Z' FRAME_-96912_SEC_VECTOR_DEF = 'CONSTANT' FRAME_-96912_SEC_FRAME = 'SPP_ECLIPDATE' FRAME_-96912_SEC_SPEC = 'RECTANGULAR' FRAME_-96912_SEC_VECTOR = ( 0, 0, 1 ) \begintext From [3] and [6]: Heliocentric Earth Equatorial (HEEQ) Frame: All vectors are geometric: no aberration corrections are used. The solar rotation axis is the primary vector: the Z axis points in the solar north direction. The position of the Earth relative to the Sun is the secondary vector: the X axis is the component of this position vector orthogonal to the Z axis. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HEEQ = -96913 FRAME_-96913_NAME = 'SPP_HEEQ' FRAME_-96913_CLASS = 5 FRAME_-96913_CLASS_ID = -96913 FRAME_-96913_CENTER = 10 FRAME_-96913_RELATIVE = 'J2000' FRAME_-96913_DEF_STYLE = 'PARAMETERIZED' FRAME_-96913_FAMILY = 'TWO-VECTOR' FRAME_-96913_PRI_AXIS = 'Z' FRAME_-96913_PRI_VECTOR_DEF = 'CONSTANT' FRAME_-96913_PRI_FRAME = 'IAU_SUN' FRAME_-96913_PRI_SPEC = 'RECTANGULAR' FRAME_-96913_PRI_VECTOR = ( 0, 0, 1 ) FRAME_-96913_SEC_AXIS = 'X' FRAME_-96913_SEC_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-96913_SEC_OBSERVER = 'SUN' FRAME_-96913_SEC_TARGET = 'EARTH' FRAME_-96913_SEC_ABCORR = 'NONE' FRAME_-96913_SEC_FRAME = 'IAU_SUN' \begintext From [3] and [5]: Heliocentric Radial Tangential Normal (RTN) Frame All vectors are geometric: no aberration corrections are used. The position of the spacecraft relative to the Sun is the primary vector: the X axis points from the Sun center to the spacecraft. The solar rotation axis is the secondary vector: the Z axis is the component of the solar north direction perpendicular to X. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_RTN = -96914 FRAME_-96914_NAME = 'SPP_RTN' FRAME_-96914_CLASS = 5 FRAME_-96914_CLASS_ID = 96914 FRAME_-96914_CENTER = 10 FRAME_-96914_RELATIVE = 'J2000' FRAME_-96914_DEF_STYLE = 'PARAMETERIZED' FRAME_-96914_FAMILY = 'TWO-VECTOR' FRAME_-96914_PRI_AXIS = 'X' FRAME_-96914_PRI_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-96914_PRI_OBSERVER = 'SUN' FRAME_-96914_PRI_TARGET = 'SPP' FRAME_-96914_PRI_ABCORR = 'NONE' FRAME_-96914_PRI_FRAME = 'IAU_SUN' FRAME_-96914_SEC_AXIS = 'Z' FRAME_-96914_SEC_VECTOR_DEF = 'CONSTANT' FRAME_-96914_SEC_FRAME = 'IAU_SUN' FRAME_-96914_SEC_SPEC = 'RECTANGULAR' FRAME_-96914_SEC_VECTOR = ( 0, 0, 1 ) \begintext From [3] and [5]: Heliocentric Ecliptic Radial Tangential Normal (HERTN) Frame All vectors are geometric: no aberration corrections are used. The position of the spacecraft relative to the Sun is the primary vector: the X axis points from the Sun center to the spacecraft. The ecliptic axis is the secondary vector: the Z axis is the component of the ecliptic north direction perpendicular to X. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HERTN = -96915 FRAME_-96915_NAME = 'SPP_HERTN' FRAME_-96915_CLASS = 5 FRAME_-96915_CLASS_ID = 96915 FRAME_-96915_CENTER = 10 FRAME_-96915_RELATIVE = 'J2000' FRAME_-96915_DEF_STYLE = 'PARAMETERIZED' FRAME_-96915_FAMILY = 'TWO-VECTOR' FRAME_-96915_PRI_AXIS = 'X' FRAME_-96915_PRI_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-96915_PRI_OBSERVER = 'SUN' FRAME_-96915_PRI_TARGET = 'SPP' FRAME_-96915_PRI_ABCORR = 'NONE' FRAME_-96915_PRI_FRAME = 'IAU_SUN' FRAME_-96915_SEC_AXIS = 'Z' FRAME_-96915_SEC_VECTOR_DEF = 'CONSTANT' FRAME_-96915_SEC_FRAME = 'SPP_ECLIPDATE' FRAME_-96915_SEC_SPEC = 'RECTANGULAR' FRAME_-96915_SEC_VECTOR = ( 0, 0, 1 ) \begintext From [3] and [7]: Heliographic Inertial (HGI) Frame: This frame is the same as the HCI frame except HGI is frozen at epoch J1900 whereas HCI is frozen at epoch J2000. All vectors are geometric: no aberration corrections are used. The solar rotation axis is the primary vector: the Z axis points in the solar north direction. The ascending node on the Earth ecliptic of J1900 of the solar equator forms the X axis. This is accomplished by using the +Z axis of the ecliptic of J1900 as the secondary vector and HGI +Y as the secondary axis. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HGI = -96916 FRAME_-96916_NAME = 'SPP_HGI' FRAME_-96916_CLASS = 5 FRAME_-96916_CLASS_ID = -96916 FRAME_-96916_CENTER = 10 FRAME_-96916_RELATIVE = 'J2000' FRAME_-96916_DEF_STYLE = 'PARAMETERIZED' FRAME_-96916_FAMILY = 'TWO-VECTOR' FRAME_-96916_PRI_AXIS = 'Z' FRAME_-96916_PRI_VECTOR_DEF = 'CONSTANT' FRAME_-96916_PRI_FRAME = 'IAU_SUN' FRAME_-96916_PRI_SPEC = 'RECTANGULAR' FRAME_-96916_PRI_VECTOR = ( 0, 0, 1 ) FRAME_-96916_SEC_AXIS = 'Y' FRAME_-96916_SEC_VECTOR_DEF = 'CONSTANT' FRAME_-96916_SEC_FRAME = 'SPP_ECLIPDATE' FRAME_-96916_SEC_SPEC = 'RECTANGULAR' FRAME_-96916_SEC_VECTOR = ( 0, 0, 1 ) FRAME_-96916_FREEZE_EPOCH = @1900-JAN-01/12:00:00 \begintext From [8]: Heliographic Co-Rotating Doppler (HGDOPP) Frame: This frame is similar to the HG Carrington frame except rotates with a frequency of 2.972 urad / s ~ 14.713... deg / day. From Snodgrass & Ulrich (1990), Table 1, Doppler Residuals Coef A. All vectors are geometric: no aberration corrections are used. The solar rotation axis is the primary vector: the Z axis points in the solar north direction. When viewed in the HCI frame, the HGDOPP X axis rotates about the Z axis in a right-handed sense at a rate of 2.972 urad / s. The HGDOPP frame of J2000 coincides with the HCI frame. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HGDOPP = -96917 FRAME_-96917_NAME = 'SPP_HGDOPP' FRAME_-96917_CLASS = 5 FRAME_-96917_CLASS_ID = -96917 FRAME_-96917_CENTER = 10 FRAME_-96917_RELATIVE = 'SPP_HCI' FRAME_-96917_DEF_STYLE = 'PARAMETERIZED' FRAME_-96917_FAMILY = 'EULER' FRAME_-96917_EPOCH = @2000-JAN-1/12:00:00 FRAME_-96917_AXES = ( 3, 1, 3 ) FRAME_-96917_UNITS = 'DEGREES' FRAME_-96917_ANGLE_1_COEFFS = ( 0, -1.70283056712880658E-04 ) FRAME_-96917_ANGLE_2_COEFFS = ( 0 ) FRAME_-96917_ANGLE_3_COEFFS = ( 0 ) \begintext From [8]: Heliographic Co-Rotating Magnetic (HGMAG) Frame: This frame is similar to the HG Carrington frame except rotates with a frequency of 2.879 urad / s ~ 14.252... deg / day. From Snodgrass & Ulrich (1990), Table 1, Magnetic Coef A. All vectors are geometric: no aberration corrections are used. The solar rotation axis is the primary vector: the Z axis points in the solar north direction. When viewed in the HCI frame, the HGMAG X axis rotates about the Z axis in a right-handed sense at a rate of 2.879 urad / s. The HGMAG frame of J2000 coincides with the HCI frame. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HGMAG = -96918 FRAME_-96918_NAME = 'SPP_HGMAG' FRAME_-96918_CLASS = 5 FRAME_-96918_CLASS_ID = -96918 FRAME_-96918_CENTER = 10 FRAME_-96918_RELATIVE = 'SPP_HCI' FRAME_-96918_DEF_STYLE = 'PARAMETERIZED' FRAME_-96918_FAMILY = 'EULER' FRAME_-96918_EPOCH = @2000-JAN-1/12:00:00 FRAME_-96918_AXES = ( 3, 1, 3 ) FRAME_-96918_UNITS = 'DEGREES' FRAME_-96918_ANGLE_1_COEFFS = ( 0, -1.64954549218164002E-04 ) FRAME_-96918_ANGLE_2_COEFFS = ( 0 ) FRAME_-96918_ANGLE_3_COEFFS = ( 0 ) \begintext From [8]: Heliographic Co-Rotating Spectroscopic (HGSPEC) Frame: This frame is similar to the HG Carrington frame except rotates with a frequency of 2.851 urad / s ~ 14.114... deg / day. From Snodgrass & Ulrich (1990), Table 1, Spectroscopic Coef A. All vectors are geometric: no aberration corrections are used. The solar rotation axis is the primary vector: the Z axis points in the solar north direction. When viewed in the HCI frame, the HGSPEC X axis rotates about the Z axis in a right-handed sense at a rate of 2.851 urad / s. The HGSPEC frame of J2000 coincides with the HCI frame. The Y axis is Z cross X, completing the right-handed reference frame. \begindata FRAME_SPP_HGSPEC = -96919 FRAME_-96919_NAME = 'SPP_HGSPEC' FRAME_-96919_CLASS = 5 FRAME_-96919_CLASS_ID = -96919 FRAME_-96919_CENTER = 10 FRAME_-96919_RELATIVE = 'SPP_HCI' FRAME_-96919_DEF_STYLE = 'PARAMETERIZED' FRAME_-96919_FAMILY = 'EULER' FRAME_-96919_EPOCH = @2000-JAN-1/12:00:00 FRAME_-96919_AXES = ( 3, 1, 3 ) FRAME_-96919_UNITS = 'DEGREES' FRAME_-96919_ANGLE_1_COEFFS = ( 0, -1.63350267391797697E-04 ) FRAME_-96919_ANGLE_2_COEFFS = ( 0 ) FRAME_-96919_ANGLE_3_COEFFS = ( 0 ) \begintext