FITS Headers
DIRBE_CIO_P3B_89365.FITS
Primary Header
SIMPLE = T / file does conform to FITS standard BITPIX = 32 / number of bits per data pixel NAXIS = 0 / number of data axes EXTEND = T / FITS dataset may contain extensions COMMENT FITS (Flexible Image Transport System) format defined in Astronomy and COMMENT Astrophysics Supplement Series v44/p363, v44/p371, v73/p359, v73/p365. COMMENT Contact the NASA Science Office of Standards and Technology for the COMMENT FITS Definition document #100 and other FITS information. DATE = '12/04/97' / FITS file creation date (dd/mm/yy) DATE-MAP= '12/07/95' / Date of original file creation (dd/mm/yy) ORIGIN = 'CDAC ' / Cosmology Data Analysis Center TELESCOP= 'COBE ' / Cosmic Background Explorer satellite INSTRUME= 'DIRBE ' / COBE instrument [DIRBE, DMR, FIRAS] OBJECT = 'DAILY-SKY' / part of sky given [e.g., ALL-SKY, WEEKLY-SKY, COMMENT / DAILY-SKY, GAL-SLICE, FACE ...] EQUINOX = 2000.0 / equinox of coords in following tables REFERENC= 'COBE/DIRBE Explanatory Supplement,' / REFERENC= 'ed. M.G. Hauser, T. Kelsall, D. Leisawitz, and J. Weiland,' / REFERENC= 'COBE Ref. Pub. No. 97-A (Greenbelt,MD: NASA/GSFC),' / REFERENC= 'available in electronic form from the NSSDC.' / COMMENT COMMENT COBE specific keywords DATE-BEG= '31/12/89' / date of initial data represented (dd/mm/yy) DATE-END= '31/12/89' / date of final data represented (dd/mm/yy) PIXRESOL= 9 / Quad tree pixel resolution [6, 9] COMMENT COMMENT DIRBE specific keywords PRODUCT = 'CIO_89365' / Calibrated Individual Obs. for YYDDD = 89365 VERSION = 'Pass 3B ' / Version of Data Reduction Software WAVE1 = '1.25 microns' / nominal wavelength of Band 1 WAVE2 = '2.2 microns' / nominal wavelength of Band 2 WAVE3 = '3.5 microns' / nominal wavelength of Band 3 WAVE4 = '4.9 microns' / nominal wavelength of Band 4 WAVE5 = '12. microns' / nominal wavelength of Band 5 WAVE6 = '25. microns' / nominal wavelength of Band 6 WAVE7 = '60. microns' / nominal wavelength of Band 7 WAVE8 = '100. microns' / nominal wavelength of Band 8 WAVE9 = '140. microns' / nominal wavelength of Band 9 WAVE10 = '240. microns' / nominal wavelength of Band 10 SOLELONG= 'ALL ' / all available solar elongations included APPVEC = 'SEPARATE' / data having different approach vectors COMMENT / are not combined during processing ZLREMOV = F / zodiacal foreground removal indicator COMMENT / if 'T(rue)', zodi foreground has been removed COMMENT / if 'F(alse)', observed sky brightness is given COMMENT COMMENT END
Extension Header 2
XTENSION= 'BINTABLE' / Extension type is Binary Table BITPIX = 8 / Binary data NAXIS = 2 / Data are in a table NAXIS1 = 109 / Number of 8 bit bytes in each row NAXIS2 = 515097 / Number of rows PCOUNT = 0 / Number of bytes of data following table GCOUNT = 1 / Group count (always 1 for bintable extensions) TFIELDS = 33 / Number of fields (columns) in the table COMMENT COMMENT TIMVERSN= 'OGIP/93-003' / GSFC Office of Guest Investigator Programs COMMENT / (OGIP) memo in which the convention is COMMENT / described COMMENT The times reported in this file are International COMMENT Atomic Time (TAI) seconds elapsed since COMMENT 00:00:00 UTC, 1 January 1981. Time information is COMMENT recorded in a manner consistent with the convention specified COMMENT in OGIP/93-003 with the understanding that time is counted COMMENT in atomic seconds and the origin of time (MJDREF) is quoted COMMENT in ephemeris MJD. TIMESYS = '1981.00 ' / time system (same as IRAS) MJDREFI = 44605 / Integer portion of ephemeris MJD COMMENT / corresponding to 0h UTC 1 Jan 1981 MJDREFF = 0.00059240741 / Fractional portion of ephemeris MJD COMMENT / corresponding to 0h UTC 1 Jan 1981 TIMEUNIT= 's ' / unit for TSTART, TSTOP, TIMEZERO = seconds TSTART = 283910405.000 / observation start time in TIMESYS system TSTOP = 283996804.999 / observation stop time in TIMESYS system COMMENT COMMENT COMMENT ------------------------------------------------------------------- COMMENT ******************************************************************* COMMENT ---- DIRBE Calibrated Individual Observations --- COMMENT ------- Cryogenic Mission, day 365 of 1989 ------ COMMENT COMMENT Calibrated individual observations (i.e., 1/8th-second COMMENT samples) of the sky as measured by each of the 16 DIRBE COMMENT detectors during the specified day. Observations COMMENT are sorted in order of increasing pixel number. COMMENT It is possible to have multiple observations of a pixel COMMENT within a day: these multiple observations are listed in COMMENT consecutive rows within the table and are COMMENT sorted in order of ascending observation time. COMMENT Reconstruction of time-ordered data strings may be COMMENT accomplished either through use of the TIME field COMMENT or the PREV_OBS/NEXT_OBS fields. COMMENT The companion Pixel Index to this day's data COMMENT may be used to determine quickly which pixels were COMMENT observed on this day and where data for specific pixels COMMENT are located within this file. COMMENT COMMENT Although observations are sorted using the DIRBE COMMENT (resolution 9) pixel number (PIXEL_NO), the position COMMENT of the boresight at the time of observation may be COMMENT reconstructed to a precision of ~20 arcsec by using the COMMENT additional pointing information provided in fields COMMENT PSUBPOS and PSBSBPOS. See the COBE/DIRBE Explanatory COMMENT Supplement description of this product (Chapter 5) for COMMENT further details. COMMENT COMMENT Before using the photometric data, the user should examine COMMENT the corresponding data quality flags. Observations COMMENT which occurred within the SAA, non-sky-survey mode data, COMMENT or time periods during which none of the DIRBE detectors met COMMENT quality standards have already been excluded from this product. COMMENT However, time periods during which data from some, but not all, COMMENT detectors are of low quality are included. In many of COMMENT these cases, the low quality detector data have been COMMENT replaced with a sentinel value to guard against inadvertent COMMENT use. There are some instances when low quality data have COMMENT neither been removed nor sentinelized. These include: COMMENT 1) intervals of excess noise for isolated detectors, COMMENT such as Band 1b lunar effects, and the occasional COMMENT microphonics noted especially in Bands 4 and 7. COMMENT The XSNOISE detector flags are included to COMMENT indicate affected observations. COMMENT 2) observations contaminated by stray light from COMMENT the Moon or Jupiter. The MOON2LOS and JUP2LOS COMMENT fields can be used to eliminate these data. COMMENT COMMENT Unlike the higher level DIRBE data products COMMENT (e.g., the DIRBE Weekly Maps, Calibrated Annual File, COMMENT Maps at Solar Elongation Angle = 90 degrees, COMMENT Galactic Plane Maps, Annual Average Maps), COMMENT the Calibrated Individual Observations product INCLUDES COMMENT data from those portions of the sky which contain COMMENT Mars, Jupiter, Saturn, Uranus, Neptune, Juno, Vesta, Ceres, COMMENT Pallas, or comets Austin, Levy, and Okazaki-Levy-Rudenko. COMMENT The JUP2LOS field indicates when Jupiter was visible; COMMENT locations of other objects can be computed using an COMMENT external ephemeris. COMMENT COMMENT The foreground signal from Zodiacal dust has not been COMMENT removed from the observations. COMMENT ******************************************************************* COMMENT -------------------------------------------------------------------- COMMENT ==================================================================== COMMENT Coordinate Information (Spatial and Temporal): COMMENT ==================================================================== COMMENT -------------------------------------------------------------------- COMMENT DIRBE Pixel number (resolution 9) TTYPE1 = 'Pixel_no' / pipeline fieldname = Pixel_no TUNIT1 = ' ' / TFORM1 = '1J ' / COMMENT -------------------------------------------------------------------- COMMENT Sub-pixel containing the DIRBE line of sight COMMENT when the DIRBE pixel specified in COMMENT field "Pixel_no" is divided into 256 COMMENT sub-pixels (16x16 grid) according COMMENT to standard quad-sphere rules COMMENT Range: [0 - 255] TTYPE2 = 'PSubPos ' / pipeline fieldname = Pixel_subpos TUNIT2 = ' ' / TFORM2 = '1B ' / COMMENT -------------------------------------------------------------------- COMMENT Sub-sub-pixel containing the DIRBE COMMENT line of sight when the DIRBE sub-pixel COMMENT specified in field "PSubPos" COMMENT is divided into 16 "sub-sub-pixels" COMMENT (4x4 grid) according to standard COMMENT quad-sphere rules. The sub-sub- COMMENT pixel number is stored in the 4 COMMENT most significant bits. Bits 0-3 COMMENT are not used. COMMENT Range: [0 - 15] TTYPE3 = 'PSbSbPos' / pipeline fieldname = Pixel_subsubpos TUNIT3 = ' ' / TFORM3 = '1B ' / TSCAL3 = 0.0625000 / divide by 16 to access bits 4-7 TZERO3 = 0.00 / COMMENT -------------------------------------------------------------------- COMMENT -------------------------------------------------------------------- COMMENT Time of observation in International Atomic Time (TAI) COMMENT seconds elapsed since 01-JAN-1981:00:00:00.000 UTC. COMMENT The reported time corresponds to the midpoint of the COMMENT 1/8th second sample interval. TTYPE4 = 'Time ' / pipeline fieldname = Time TUNIT4 = 's ' / TFORM4 = '1D ' / COMMENT -------------------------------------------------------------------- COMMENT Number of the row within this FITS binary table which COMMENT contains the next observation in the time-ordered sequence. COMMENT Usually the time of the next observation is TIME + 1/8 sec, COMMENT but gaps in the time sequence do exist. COMMENT Next_obs is set to -1 if the time of the next observation COMMENT lies outside the time boundaries defined for this file. TTYPE5 = 'Next_obs' / pipeline fieldname = Next_obs TUNIT5 = ' ' / TFORM5 = '1J ' / COMMENT -------------------------------------------------------------------- COMMENT Number of the row within this FITS binary table which contains COMMENT the previous observation in the time-ordered sequence. COMMENT Usually the time of the previous observation is COMMENT TIME - 1/8 sec, but gaps in the time sequence do exist. COMMENT Prev_obs is set to -1 if the time of the preceding observation COMMENT lies outside the time boundaries defined for this file. TTYPE6 = 'Prev_obs' / pipeline fieldname = Prev_obs TUNIT6 = ' ' / TFORM6 = '1J ' / COMMENT -------------------------------------------------------------------- COMMENT -------------------------------------------------------------------- COMMENT ==================================================================== COMMENT DIRBE Sky Brightness and Polarization Information: COMMENT ==================================================================== COMMENT -------------------------------------------------------------------- COMMENT The following 16 columns tabulate the 1/8th second COMMENT photometric samples taken for the each of the 16 COMMENT DIRBE detectors at the time of observation. COMMENT The photometric measurements COMMENT are given as spectral intensities, I(nu) in MJy/sr, and COMMENT are quoted at the nominal wavelength COMMENT for a source with nu*I(nu) = constant -- i.e., COMMENT a color correction is required if the source COMMENT spectrum differs from nu*I(nu) = constant. COMMENT Data which have been replaced by flagged (sentinel) values COMMENT in processing have values .LE. -16375. COMMENT COMMENT Photometry for band 1, channel A (1A: 1.25 um, full intensity) TTYPE7 = 'Phot1A ' / pipeline fieldname = Photometry(1) TUNIT7 = 'MJy/sr ' / TFORM7 = '1E ' / COMMENT Photometry for band 1, channel B (1B: 1.25 um, polarized light) TTYPE8 = 'Phot1B ' / pipeline fieldname = Photometry(2) TUNIT8 = 'MJy/sr ' / TFORM8 = '1E ' / COMMENT Photometry for band 1, channel C (1C: 1.25 um, polarized light) TTYPE9 = 'Phot1C ' / pipeline fieldname = Photometry(3) TUNIT9 = 'MJy/sr ' / TFORM9 = '1E ' / COMMENT Photometry for band 2, channel A (2A: 2.2 um, full intensity) TTYPE10 = 'Phot2A ' / pipeline fieldname = Photometry(4) TUNIT10 = 'MJy/sr ' / TFORM10 = '1E ' / COMMENT Photometry for band 2, channel B (2B: 2.2 um, polarized light) TTYPE11 = 'Phot2B ' / pipeline fieldname = Photometry(5) TUNIT11 = 'MJy/sr ' / TFORM11 = '1E ' / COMMENT Photometry for band 2, channel C (2C: 2.2 um, polarized light) TTYPE12 = 'Phot2C ' / pipeline fieldname = Photometry(6) TUNIT12 = 'MJy/sr ' / TFORM12 = '1E ' / COMMENT Photometry for band 3, channel A (3A: 3.5 um, full intensity) TTYPE13 = 'Phot3A ' / pipeline fieldname = Photometry(7) TUNIT13 = 'MJy/sr ' / TFORM13 = '1E ' / COMMENT Photometry for band 3, channel B (3B: 3.5 um, polarized light) TTYPE14 = 'Phot3B ' / pipeline fieldname = Photometry(8) TUNIT14 = 'MJy/sr ' / TFORM14 = '1E ' / COMMENT Photometry for band 3, channel C (3C: 3.5 um, polarized light) TTYPE15 = 'Phot3C ' / pipeline fieldname = Photometry(9) TUNIT15 = 'MJy/sr ' / TFORM15 = '1E ' / COMMENT Photometry for band 4 (4.9 um) TTYPE16 = 'Phot04 ' / pipeline fieldname = Photometry(10) TUNIT16 = 'MJy/sr ' / TFORM16 = '1E ' / COMMENT Photometry for band 5 (12 um) TTYPE17 = 'Phot05 ' / pipeline fieldname = Photometry(11) TUNIT17 = 'MJy/sr ' / TFORM17 = '1E ' / COMMENT Photometry for band 6 (25 um) TTYPE18 = 'Phot06 ' / pipeline fieldname = Photometry(12) TUNIT18 = 'MJy/sr ' / TFORM18 = '1E ' / COMMENT Photometry for band 7 (60 um) TTYPE19 = 'Phot07 ' / pipeline fieldname = Photometry(13) TUNIT19 = 'MJy/sr ' / TFORM19 = '1E ' / COMMENT Photometry for band 8 (100 um) TTYPE20 = 'Phot08 ' / pipeline fieldname = Photometry(14) TUNIT20 = 'MJy/sr ' / TFORM20 = '1E ' / COMMENT Photometry for band 9 (140 um) TTYPE21 = 'Phot09 ' / pipeline fieldname = Photometry(15) TUNIT21 = 'MJy/sr ' / TFORM21 = '1E ' / COMMENT Photometry for band 10 (240 um) TTYPE22 = 'Phot10 ' / pipeline fieldname = Photometry(16) TUNIT22 = 'MJy/sr ' / TFORM22 = '1E ' / COMMENT -------------------------------------------------------------------- COMMENT ==================================================================== COMMENT DIRBE Viewing Geometry and External Influences Information: COMMENT ==================================================================== COMMENT -------------------------------------------------------------------- COMMENT Angle between DIRBE boresight (or line of sight, LOS) and COMMENT spacecraft orbital velocity vector. COMMENT Range = [0, 180] degrees TTYPE23 = 'LOS2VelV' / pipeline fieldname = BS_re_Vel TUNIT23 = 'deg ' / TFORM23 = '1I ' / TSCAL23 = 0.0109867 / bin size 360/(2**15 -1) degrees TZERO23 = 0.00549333 / offset to bin center in degrees COMMENT -------------------------------------------------------------------- COMMENT Approach Vector COMMENT Divides observations into two groups: COMMENT those which are looking in the forward direction of COMMENT spacecraft motion, and those which are looking backwards COMMENT from the direction of spacecraft motion. COMMENT Approach Vector 1 (AV1): COMMENT Forward looking, i.e., 0 .LE. LOS2VelV .LE. 90 deg COMMENT Approach Vector 2 (AV2): COMMENT Backward looking, i.e., 90 .LT. LOS2VelV .LE. 180 deg TTYPE24 = 'ApprVec ' / pipeline fieldname = Approach_vector TUNIT24 = ' ' / TFORM24 = '1B ' / COMMENT -------------------------------------------------------------------- COMMENT Attack Vector COMMENT A vector whose three components specify the rate of change COMMENT (derivative with respect to time) of the DIRBE boresight COMMENT unit vector (i.e. the rate of change of the direction COMMENT cosines in geocentric ecliptic coordinates). COMMENT The Attack Vector is computed from the cross product of COMMENT the spacecraft angular velocity vector (which includes both COMMENT orbital and spin components) and the boresight. COMMENT The Attack Vector points in the DIRBE scan direction COMMENT across the sky, and is normal to the leading edge of the COMMENT field of view (FOV). The length of this vector gives the COMMENT scan rate in radians/sec. COMMENT Nominal range for scan rate: .041 - .044 rad/sec TTYPE25 = 'AttackV ' / pipeline fieldname = Attack_vector TUNIT25 = ' ' / TFORM25 = '3I ' / TDIM25 = '(3) ' / TSCAL25 = 0.0000305176 / bin size 1./(2**15) per second TZERO25 = 0.00 / see ExSupp for offset to bin center in /sec COMMENT -------------------------------------------------------------------- COMMENT Azimuth of the Attack Vector, COMMENT computed as a positive or negative rotation angle about COMMENT the DIRBE boresight in the plane normal to the boresight COMMENT vector (i.e., the plane of the field of view (FOV)). COMMENT Azimuth is measured with respect to the fiducial vector COMMENT defined by the cross product of the DIRBE spin axis and COMMENT boresight vectors, and is positive if the rotation sense COMMENT is the same as that of the spacecraft (i.e., azimuth = COMMENT +90 deg. points toward the spin axis, following the COMMENT right-hand sign convention). COMMENT Range = (-180, 180] degrees COMMENT Nominal range: [-2,+2] degrees TTYPE26 = 'AtV_Azim' / pipeline fieldname = FOV_Azimuth TUNIT26 = 'deg ' / TFORM26 = '1I ' / TSCAL26 = 0.0109867 / bin size 360/(2**15 -1) degrees TZERO26 = 0.00549333 / offset to bin center in degrees COMMENT -------------------------------------------------------------------- COMMENT Solar elongation of observation, COMMENT i.e. angle between the vector from the spacecraft to the COMMENT center of the Sun and the DIRBE line of sight (boresight). COMMENT Nominal range = [64, 124] degrees TTYPE27 = 'SolElong' / pipeline fieldname = Sun_re_BS (word 1) TUNIT27 = 'deg ' / TFORM27 = '1I ' / TSCAL27 = 0.0109867 / bin size 360/(2**15 -1) degrees TZERO27 = 0.00549333 / offset to bin center in degrees COMMENT -------------------------------------------------------------------- COMMENT Angle between the vector from the spacecraft to the center COMMENT of the moon and the DIRBE line of sight (boresight). COMMENT Observations for which Moon2LOS .LE. 10 degrees are COMMENT potentially contaminated by lunar stray light. TTYPE28 = 'Moon2LOS' / pipeline fieldname = Moon_re_BS (word 1) TUNIT28 = 'deg ' / TFORM28 = '1I ' / TSCAL28 = 0.0109867 / bin size 360/(2**15 -1) degrees TZERO28 = 0.00549333 / offset to bin center in degrees COMMENT -------------------------------------------------------------------- COMMENT Azimuth of the Moon COMMENT The vector from the spacecraft to the center of the Moon COMMENT is projected onto the plane normal to the boresight vector COMMENT (i.e., the plane of the field of view (FOV)). COMMENT The azimuth of this projected vector is then computed as a COMMENT positive or negative rotation angle about the DIRBE boresight. COMMENT Azimuth is measured with respect to the fiducial vector COMMENT defined by the cross product of the DIRBE spin axis and COMMENT boresight vectors, and is positive if the rotation sense COMMENT is the same as that of the spacecraft (i.e., azimuth = COMMENT +90 deg. points toward the spin axis, following the COMMENT right-hand sign convention). The AtV_Azim field gives COMMENT the relationship between the Attack Vector and the COMMENT zero azimuth fiducial. COMMENT Range = (-180, 180] degrees TTYPE29 = 'MoonAzim' / pipeline fieldname = Moon_re_BS (word 2) TUNIT29 = 'deg ' / TFORM29 = '1I ' / TSCAL29 = 0.0109867 / bin size 360/(2**15 -1) degrees TZERO29 = 0.00549333 / offset to bin center in degrees COMMENT -------------------------------------------------------------------- COMMENT Angle between the vector from the spacecraft to the center COMMENT of Jupiter and the DIRBE line of sight (boresight). COMMENT Observations for which Jup2LOS .LE. 1.5 degrees are COMMENT potentially contaminated by stray light from Jupiter. TTYPE30 = 'Jup2LOS ' / pipeline fieldname = Jupiter_re_BS (word 1) TUNIT30 = 'deg ' / TFORM30 = '1I ' / TSCAL30 = 0.0109867 / bin size 360/(2**15 -1) degrees TZERO30 = 0.00549333 / offset to bin center in degrees COMMENT -------------------------------------------------------------------- COMMENT Radiation Zone flag COMMENT Flag indicates if the spacecraft was within the COMMENT South Atlantic Anomaly (SAA), North Van Allen Belt (NVAB) COMMENT or South Van Allen Belt (SVAB) at the time of observation. COMMENT Radiation zone boundaries for the mission were defined COMMENT according to the number of radiation hits received as a COMMENT function of COBE subsatellite position. If the subsatellite COMMENT position at the time of observation was contained within COMMENT a zone's defined boundaries, then the flag for that zone COMMENT is set. Subsatellite position is updated every COMMENT 32 seconds. COMMENT Observations occurring within the SAA COMMENT have already been eliminated; observations made within the COMMENT NVAB and SVAB remain in the dataset. COMMENT Bit 0 (LSB) = 1 if in NVAB ; 0 if clear of NVAB COMMENT Bit 1 = 1 if in SVAB ; 0 if clear of SVAB COMMENT Bit 2 = 1 if in SAA ; 0 if clear of SAA COMMENT Bits 3-7 Not Used TTYPE31 = 'RadZone ' / pipeline fieldname = Radiation_cont TUNIT31 = ' ' / TFORM31 = '1B ' / COMMENT -------------------------------------------------------------------- COMMENT Excess Noise Flags (per detector) COMMENT Flags indicating if exceptionally noisy data were recorded COMMENT by any of the 16 detectors during the 32-second COMMENT long Major Frame that included this observation. COMMENT Detector observations for which the flag is set COMMENT are unreliable and should not be used. COMMENT The 16-bit field is encoded so that each bit represents one COMMENT of the 16 detectors. Bits are assigned in detector order: COMMENT 1A,1B,1C,2A,2B,2C,3A,3B,3C,4,5,6,7,8,9,10, where COMMENT Bit 0 (least significant bit) = 1 if Detector 1A excessively noisy COMMENT ... up through COMMENT Bit 15 (most significant bit) = 1 if Detector 10 excessively noisy TTYPE32 = 'XSNoise ' / pipeline fieldname = Glitch_Flags TUNIT32 = ' ' / TFORM32 = '1I ' / COMMENT -------------------------------------------------------------------- COMMENT Orbit and Attitude Flags. COMMENT Miscellaneous orbit and attitude COMMENT information encoded into a single byte. The individual COMMENT bits are interpreted as follows, where Bit 0 is the COMMENT least significant bit: COMMENT Flags indicating attitude used COMMENT Bit 0 = 1 if non-definitive attitude COMMENT = 0 if definitive attitude used COMMENT Bit 1 = 1 if coarse attitude used COMMENT = 0 if fine attitude used COMMENT Bit 2 = 1 if merged attitude used COMMENT = 0 if external (UAX) attitude used COMMENT Flags describing attitude control COMMENT Bit 3 = 1 if spacecraft slewing COMMENT = 0 otherwise COMMENT Bit 4 = 1 during Special Pointing COMMENT = 0 otherwise COMMENT Node Flag COMMENT Bit 5 = 1 when spacecraft (NOT LOS) in ascending COMMENT portion of COBE orbit, i.e., moving COMMENT up towards North Ecliptic Pole COMMENT = 0 when spacecraft (NOT LOS) in descending COMMENT portion of COBE orbit, i.e., moving COMMENT down towards South Ecliptic Pole COMMENT Leading/Trailing Flag COMMENT Plane passing through Sun, Earth and ecliptic poles COMMENT divides sky into two halves: COMMENT Bit 6 = 1 when LOS is pointed to that half of sky COMMENT LEADING earth orbital motion COMMENT = 0 when LOS is pointed to that half of sky COMMENT TRAILING earth orbital motion COMMENT Bit 7 Not Used TTYPE33 = 'OA_Flags' / pipeline fieldname = ATT_Flags TUNIT33 = ' ' / TFORM33 = '1B ' / COMMENT -------------------------------------------------------------------- END
