Astrosat Project Level2 Interface Control Document

Transcription

1 Astrosat Project Level2 Interface Control Document Level2 Data Pipeline Software For Soft X-Ray Telescope (SXT) SAC DP Team Navita Thakkar, Arvind K Singh, T. P. Srinivasan, B. Gopala Krishna Instrument Team Harshal Pawar, Kallol Mukerjee (TIFR) August 2012 High Resolution Data Processing Division Satellite Photogrammetry and Digital Cartography Group Signal and Image Processing Area Space Applications Centre Ahmedabad

2 Space Applications Centre (ISRO), Ahmedabad Document Control and Data Sheet 1 Report No & Date : AstrosatDPSACSIPASPDCGHRDPDTR-5(c)Aug Title : Astrosat Project- Level2 Interface Control Document Level2 data pipeline software for Soft X-ray Telescope(SXT) 3 Version : No. of Pages : 31 4 No. of References : 4 5 Authors : SAC DP Team Navita Thakkar, Arvind K. Singh, T. P. Srinivasan, B. Gopala Krishna Instrument Team -Harshal Pawar, Kallol Mukerjee (TIFR) 6 Originating Unit : High Resolution Data Processing Division, Satellite Photogrammetry and Digital Cartography Group, Signal and Image Processing Area. 7 Abstract : This document describes the Level2 output data formats to be generated from Level2 data pipeline software. 8 Keywords : Astrosat, SXT, Level2, MKF, FITS, PHA 9 Security Classification : Restricted 2

3 Document Change History *A: Addition; M: Modification; D: Deletion Version Date Section AMD * Description of change No. No. V 1.0 Aug All A Initial Version 3

4 CONTENTS DOCUMENT CONTROL AND DATA SHEET... 2 DOCUMENT CHANGE HISTORY INTRODUCTION LEVEL2 DATA ORGANIZATION LEVEL2 OUTPUT DATA FORMATS LEVEL2 EVENT FILE PRIMARY HEADER FITS FORMAT EVENTS HEADER FITS FORMAT GTI HEADER FITS FORMAT GTI FILE PRIMARY HEADER FITS FORMAT GTI HEADER FITS FORMAT LIGHT CURVE FILE PRIMARY HEADER FITS FORMAT RATE HEADER FITS FORMAT SPECTRUM FILE PRIMARY HEADER FITS FORMAT SPECTRUM HEADER FITS FORMAT IMAGE FILE PRIMARY HEADER FITS FORMAT TCT FILE PRIMARY HEADER FITS FORMAT TCT HEADER FITS FORMAT MKF FILE PRIMARY HEADER FITS FORMAT MKF HEADER FITS FORMAT LBT HK FILE PRIMARY HEADER FITS FORMAT LBT HK HEADER FITS FORMAT ORBIT FILE PRIMARY HEADER FITS FORMAT ORBIT HEADER FITS FORMAT ATTITUDE FILE PRIMARY HEADER FITS FORMAT ATTITUDE HEADER FITS FORMAT REFERENCES

5 Soft X-Ray Telescope (SXT) Level2 Data Organization and File Formats 1. Introduction The Level2 ICD contains Level2 output data files format for the Soft X-Ray Telescope (SXT) of Astrosat. All the outputs files will be in FITS Format. The Level2 Output data files are Level2 Event File (.evt) Intermediate Event Files (.tmp) GTI file (.gti) Light Curve File (.lc) Spectrum File (.spec) Image File (.img) The Other ancillary files are inherited from the Level1 are Time Calibration Table (TCT) Data File Make Filter (MKF) Data File Low Bitrate Telemetry (LBT) House Keeping file Orbit File Attitude File 2. Level2 Data Organization The directory structure for data organization after level2 processing is given below. The files under yyyymmdd_<obsid>_level2directory will be generated during level2 data processing and other files viz. hk file, attitude file, orbit file, mkf file will be copied from level1 to level2 directory. File names will bear the mode and window settings, MM and WW respectively yyyymmdd_<obsid>_level2 sxt AS1<ObsID>sxtMMWW_level2.evt AS1<ObsID>sxtMMWW_level2.lc AS1<ObsID>sxtMMWW_level2.spec AS1<ObsID>sxtMMWW_level2.img AS1<ObsID>sxtMMWW_level2.gti AS1<ObsID>sxtMMWW_level2.bti hk aux AS1<ObsID>sxt_level2.mkf 5

6 AS1<ObsID>sxt_level2.tct aux1 AS1<ObsID>sxt_level2.att AS1<ObsID>sxt_level2.orb aux2 AS1<ObsID>sxt_level2.lbt 3. Level2 output data formats The detailed format description for all the Level2 data files are described in detail in respective sections which shown below. 3.1 Level2 Event File File Name: AS1<OBSID>sxtMMWW_level2.evt Where OBSID is observation ID, MM is the Mode, WW is the Window Setting Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions MISSION = 'ASTROSAT' ORIGIN = 'ASTROSAT-SXT-L2' Configuration Control CREATOR = 'SXT-L2 ' TELESCOP = 'ASTROSAT' INSTRUME = 'SXT ' CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) = MJD = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time 6

7 OBJECT = Source information block RA_PNT = Nominal pointing DEC_PNT = Nominal pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = Observation Id SOURCEID = Source Id TARGETID = Target Id EXP_TIME = Exposure Time ORB_NUM = nnnnn Orbit Number EVENTS Header FITS format XTENSION = 'BINTABLE' binary table extension BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional binary table NAXIS1 = 57 width of table in bytes NAXIS2 = number of rows in table PCOUNT = 0 size of special data area: GCOUNT = 1 one data group (required keyword) TFIELDS = 15 number of fields in each row EXTNAME = EVENTS EVENTS Extension Name TTYPE1 = 'TIME Time of events TFORM1 = '1D data format of field TUNIT1 = 's physical unit of field TTYPE2 = 'CCDFrame' CCD FRAME number TFORM2 = '1J data format of field TZERO2 = data offset TTYPE3 = 'X Event X position Sky coordinates TFORM3 = '1I data format of field TUNIT3 = 'pixel physical unit of field TLMIN3 = 1 Minimum value for X column TLMAX3 = 1000 Maximum value for X column TTYPE4 = 'Y Event Y position Sky coordinates TFORM4 = '1I data format of field TUNIT4 = 'pixel physical unit of field TLMIN4 = 1 Minimum value for Y column TLMAX4 = 1000 Maximum value for Y column TTYPE5 = 'RAWX Event X position RAW coordinates TFORM5 = '1I data format of field TUNIT5 = 'pixel physical unit of field TLMIN5 = 0 minimum legal value in the column TLMAX5 = 599 maximum legal value in the column TTYPE6 = 'RAWY Event Y position RAW coordinates TFORM6 = '1I data format of field TUNIT6 = 'pixel physical unit of field 7

8 TLMIN6 = 0 minimum legal value in the column TLMAX6 = 599 maximum legal value in the column TTYPE7 = 'DETX Event X position DET coordinates TFORM7 = '1I data format of field TUNIT7 = 'pixel physical unit of field TLMIN7 = 1 Minimum value for DETX column TLMAX7 = 600 Maximum value for DETX column TTYPE8 = 'DETY Event Y position DET coordinates TFORM8 = '1I data format of field TUNIT8 = 'pixel physical unit of field TLMIN8 = 1 Minimum value for DETY column TLMAX8 = 600 Maximum value for DETY column TTYPE9 = 'PHAS Array of Pulse Height Analyzer values TFORM9 = '9I data format of field TUNIT9 = 'chan physical unit of field TLMIN9 = 0 minimum legal value in the column TLMAX9 = 4095 maximum legal value in the column TTYPE10 = 'Amp Amplifier node used for readout TFORM10 = '1B data format of field TTYPE11 = 'PHA Pulse Height Analyzer after event recognition TFORM11 = '1J data format of field TUNIT11 = 'chan physical unit of field TLMIN11 = 0 minimum legal value in the column TLMAX11 = 4095 maximum legal value in the column TTYPE12 = 'PI Pulse invariant TFORM12 = '1J data format of field TUNIT12 = 'chan physical unit of field TLMIN12 = minimum legal value in the column TLMAX12 = maximum legal value in the column TTYPE13 = 'GRADE Event Grade TFORM13 = '1I data format of field TTYPE14 = 'PixsAbove' Number of Pixels used for PHA reconstruction TFORM14 = '1I data format of field TTYPE15 = 'STATUS Event Quality Flag TFORM15 = '16X data format of field TIMESYS = 'TT Time system MJDREFI = Reference MJD Integer part MJDREFF = Reference MJD fractional TIMEREF = 'LOCAL Time reference (barycenter local) TASSIGN = 'SATELLITE' Time assigned by clock TIMEUNIT = 's Time unit TSTART = Start time TSTOP = Stop time 8

9 DATE-OBS = Date and time of observation start DATE- = Date and time of observation stop TELAPSE = TSTOP - TSTART TELESCOP = Telescope (mission) name INSTRUME = Instrument name DATAMODE = Instrument operating mode OBS_ID = TARG_ID = Target ID EQUINOX = default RADECSYS = default OBS_MODE = default ORIGIN = Source of FITS file CREATOR = Program that created this FITS file DATE = file creation date (YYYY-MM-DDThh:mm:ss UT) GTI Header FITS format XTENSION = BINTABLE' Binary table extension BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional Binary Table NAXIS1 = Width of table in bytes NAXIS2 = Number of rows in table PCOUNT = 0 Size of special data area GCOUNT = 1 Number of data groups TFIELDS = 2 Number of fields in each row EXTNAME = GTI name of this binary table extension ORIGIN = SXT-L1 CREATOR = SXT-L1 HDUCLASS = OGIP format conforms to OGIP GSFC standards LONGSTRN = OGIP 1.0' The OGIP long string convention may be used. CHECKSUM = HDU checksum DATASUM = Data checksum, ASCII encoded DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) TIMEDEL = integration time TTYPE1 = START label for field 1 TFORM1 = 1D data format of field: 8-byte DOUBLE TUNIT1 = sec physical unit of field TTYPE2 = STOP label for field 2 TFORM2 = 1D data format of field: 8-byte DOUBLE TUNIT2 = sec physical unit of field 3.2 GTI File File Name: AS1<OBSID>sxtMMWW_level2.gti Where OBSID is observation ID, MM is the Mode, WW is the Window Setting 9

10 3.1.4 Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions ORIGIN = ASTROSAT-SXT-L1' Configuration control DATE = file creation date (YYYY-MM-DDThh:mm:ss UT) TELESCOP = ASTROSAT' mission name CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data DATE- = End date for data TIME- = End time for data TIMESYS = TT' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) MJD = JD TIMEUNIT = s TSTOPI = integer observation stop time TSTOPF = fractional observation stop time TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution CREATOR = Program name that produced this file GTI Header FITS format XTENSION = BINTABLE' Binary table extension BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional Binary Table NAXIS1 = Width of table in bytes NAXIS2 = Number of rows in table PCOUNT = 0 Size of special data area GCOUNT = 1 Number of data groups TFIELDS = 2 Number of fields in each row EXTNAME = GTI name of this binary table extension ORIGIN = SXT-L1 CREATOR = SXT-L1 HDUCLASS = OGIP format conforms to OGIP GSFC standards LONGSTRN = OGIP 1.0' The OGIP long string convention may be used. CHECKSUM = HDU checksum DATASUM = Data checksum, ASCII encoded DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) TIMEDEL = integration time TTYPE1 = START label for field 1 TFORM1 = 1D data format of field: 8-byte DOUBLE TUNIT1 = sec physical unit of field TTYPE2 = STOP label for field 2 10

11 TFORM2 = 1D data format of field: 8-byte DOUBLE TUNIT2 = sec physical unit of field 3.3 Light Curve File File Name: AS1<OBSID>sxtMMWW_level2.lc Where OBSID is observation ID, MM is the Mode, WW is the Window Setting Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions MISSION = 'ASTROSAT' ORIGIN = 'ASTROSAT-SXT-L2' Configuration Control CREATOR = 'SXT-L2 ' TELESCOP = 'ASTROSAT' INSTRUME = 'SXT ' CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) = MJD = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time OBJECT = Source information block RA_PNT = Nominal pointing DEC_PNT = Nominal pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = Observation Id SOURCEID = Source Id TARGETID = Target Id EXP_TIME = Exposure Time ORB_NUM = nnnnn Orbit Number 11

12 3.4.2 RATE Header FITS format XTENSION = 'BINTABLE' Binary table Extension BITPIX = 8 8-bit bytes NAXIS = 2 2 dimensional binary axis NAXIS1 = Number of bytes per row NAXIS2 = Number of rows PCOUNT = 0 No group parameters GCOUNT = 1 one data group TFIELDS = 4 Number of columns EXTNAME = 'RATE' CREATOR = Module that created the file HDUVERS = '1.0.0' HDUCLASS = 'OGIP' HDUCLAS1 = 'ARRAY' LONGSTRN = 'OGIP 1.0' The OGIP long string convention may be used CHECKSUM = HDU checksum OBS_MODE = Pointing, slew, scan RA_OBJ = RA Object DEC_OBJ = DEC Object TTYPE1 = 'Time' label for field 1 TFORM1 = '1D' data format of field: 8-byte DOUBLE TUNIT1 = s TTYPE2 = 'RATE' label for field 2 TFORM2 = '1E' data format of field: 4-byte FLOAT TUNIT2 = counts TTYPE3 = 'ERROR' label for field 3 TFORM3 = '1E' data format of field: 4-byte FLOAT TUNIT3 = counts TTYPE4 = 'FRACEXP' label for field 4 TFORM4 = '1E' data format of field: 4-byte FLOAT TUNIT4 = counts BINSIZE = TSTART = Start Time TSTOP = End Time 3.4 Spectrum File File Name: AS1<OBSID>sxtMMWW_level2.spec Where OBSID is observation ID, MM is the Mode, WW is the Window Setting Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions MISSION = 'ASTROSAT' 12

13 ORIGIN = 'ASTROSAT-SXT-L2' Configuration Control CREATOR = 'SXT-L2 ' TELESCOP = 'ASTROSAT' INSTRUME = 'SXT ' CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) = MJD = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time OBJECT = Source information block RA_PNT = Nominal pointing DEC_PNT = Nominal pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = Observation Id SOURCEID = Source Id TARGETID = Target Id EXP_TIME = Exposure Time ORB_NUM = nnnnn Orbit Number SPECTRUM Header FITS format XTENSION = 'BINTABLE' Binary table Extension BITPIX = 8 8-bit bytes NAXIS = 2 2 dimensional binary axis NAXIS1 = Number of bytes per row NAXIS2 = Number of rows PCOUNT = 0 No group parameters GCOUNT = 1 one data group TFIELDS = 2 Number of columns EXTNAME = 'SPECTRUM' CREATOR = Module that created the file HDUVERS = '1.0.0' HDUCLASS = 'OGIP' HDUCLAS1 = 'ARRAY' 13

14 LONGSTRN = 'OGIP 1.0' The OGIP long string convention may be used CHECKSUM = HDU checksum OBS_MODE = Pointing, slew, scan RA_OBJ = RA Object DEC_OBJ = DEC Object TTYPE1 = 'CHANNEL' label for field 1 TFORM1 = '1J' data format of field: 4-byte LONG TUNIT1 = s TTYPE2 = 'COUNTS' label for field 2 TFORM2 = '1J' data format of field: 4-byte LONG TUNIT2 = count BINSIZE = TSTART = Start Time TSTOP = End Time 3.5 Image File File Name: AS1<OBSID>sxtMMWW_level2.img Where OBSID is observation ID, MM is the Mode, WW is the Window Setting Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of Bits per data pixel NAXIS = 2 Number of data axis NAXIS1 = 1000 NAXIS2 = 1000 EXT = T FITS data sets may include extension MISSION = ASTROSAT ORIGIN = ASTROSAT-SXT-L2 CREATOR = Module name that created the file CHECKSUM = ASCII encoded HDU checksum DATE = File Creation date (YYYY-MM-DDhh:mm:ss UTC) INSTRUME = SXT TELESCOPE = DATE-OBS = start date for data TIME-OBS = start time for data DATE- = end date for data TIME- = end time for data TIMESYS = TT Time will be TT (terrestrial time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = TIMEZERO = Clock correction TIMEUNIT = s Unit of time -seconds TSTOPI = integer observation stop time TSTOPF = fractional observation stop time TIMEZERI = clock correction integer TIMEZERF = clock correction fractional TIMEDEL = Time Resolution (UTC) expressed in TT(fractional part) MJD=JD

15 OBJECT = Source Information block RA_PNT = Nominal Pointing DEC_PNT = Nominal Pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = Observation Id SOURCEID = Source Id TARGETID = Target Id EXP_TIME = Exposure Time ORB_NUM = nnnnn Orbit Number 3.6 TCT File File Name: AS1<OBSID>sxt_level2.tct Where OBSID is observation ID Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions ORIGIN = 'ASTROSAT-SXT-L2' Configuration control CREATOR = 'SXT-L1 ' Program name that produced this file TELESCOP = 'ASTROSAT ' Telescope (mission) name CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) MJD = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time TCT Header FITS format XTENSION = 'BINTABLE' Binary table extension BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional Binary Table 15

16 NAXIS1 = 24 Width of table in bytes NAXIS2 = Number of rows in table PCOUNT = 0 Size of special data area GCOUNT = 1 Number of data groups TFIELDS = 3 Number of fields in each row EXTNAME = 'TCT ' name of this binary table extension ORIGIN = 'SXT-L2 ' CREATOR = 'SXT-L2 ' = HDUVERS = '1.1.0 ' Version number of the format HDUCLASS = 'OGIP ' format conforms to OGIPGSFC standards HDUCLAS1 = 'TIME CORRELATION' Extension contains time correlation of frames HDUCLAS2 = 'SPS_OBT_STBG' Extension contains time correlation of frames HDUVERS1 = '1.1.0 ' Version number of the format LONGSTRN = 'OGIP 1.0' The OGIP long string convention may be used. = CHECKSUM = HDU checksum DATASUM = Data checksum, ASCII encoded = TTYPE1 = 'SPS_TIME' SPS time TFORM1 = '1D ' data format of field: 8-byte DOUBLE TUNIT1 = 's ' physical unit of field = TTYPE2 = 'OBT_TIME' OBT time TFORM2 = '1D ' data format of field: 8-byte DOUBLE TUNIT2 = 's ' physical unit of field TTYPE3 = 'STBG_TIME' STBG time TFORM3 = '1D ' data format of field: 8-byte DOUBLE TUNIT3 = 's ' physical unit of field 3.7 MKF File File Name: AS1<OBSID>sxt_level2.mkf Where OBSID is observation ID Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions ORIGIN = 'ASTROSAT-SXT-L2' Configuration control CREATOR = 'SXT-L2 ' TELESCOP = 'ASTROSAT' INSTRUME = 'SXT ' CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data 16

17 DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) = MJD = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time OBJECT = Source information block RA_PNT = Nominal pointing DEC_PNT = Nominal pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = MKF Header FITS format XTENSION = 'BINTABLE' Binary table Extension BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional Binary Table NAXIS1 = 164 Number of bytes per row NAXIS2 = Number of rows PCOUNT = 0 No group parameters (required keyword) GCOUNT = 1 One data group (required keyword) TFIELDS = 36 Number of columns EXTNAME = 'MKF Satellite information relevant for SXT ORIGIN = 'SXT-L21' CREATOR = 'SXT-L2' HDUVERS = '1.0.0 ' HDUCLASS = 'OGIP ' LONGSTRN = 'OGIP 1.0' The OGIP long string convention may be used. CHECKSUM = HDU checksum DATASUM = Data checksum, ASCII encoded TTYPE1 = 'Time ' Time : Time stamp (sec since 1 Jan 2010) TUNIT1 = 's ' TFORM1 = 'D ' format of field TTYPE2 = 'Q_SAT ' Spacecraft Quaternion (Order Q1, Q2, Q3, Q4), TFORM2 = '4D ' Array 0f 4 each 8-byte Double TTYPE3 = 'Roll_RA ' (deg) RA of the SC Roll(Pointing Axis) TFORM3 = '1E ' 4-byte float TUNIT3 = 'deg ' Unit 17

18 TTYPE4 = 'Roll_DEC ' (deg) DEC of the SC Roll(Pointing Axis) TFORM4 = '1E ' 4-byte float TUNIT4 = 'deg ' Unit TTYPE5 = 'ROLL_ROT' (deg) Rotation about SC Roll axis (Twist) TFORM5 = '1E ' 4-byte float TUNIT5 = 'deg ' Unit TTYPE6 = 'PITCH_RA' Spacecraft Pitch Axis RA TFORM6 = '1E ' format of field TUNIT6 = 'deg ' Unit TTYPE7 = 'PITCH_DEC' Spacecraft Pitch Axis DEC TFORM7 = '1E ' format of field TUNIT7 = 'deg ' Unit TTYPE8 = 'YAW_RA ' Spacecraft Yaw Axis RA TFORM8 = '1E ' format of field TUNIT8 = 'deg ' Unit TTYPE9 = 'YAW_DEC ' Spacecraft Yaw Axis DEC TFORM9 = '1E ' format of field TUNIT9 = 'deg ' Unit TTYPE10 = 'POSX ' Spacecraft Position, X-axis TFORM10 = 'E ' format of field TUNIT10 = 'm ' TTYPE11 = 'POSY ' Spacecraft Position, Y-axis TFORM11 = 'E ' format of field TUNIT11 = 'm ' TTYPE12 = 'POSZ ' Spacecraft Position, Z-axis TFORM12 = 'E ' format of field TTYPE13 = 'VELX ' Spacecraft Velocity, X-axis TFORM13 = 'E ' format of field TUNIT13 = 'kms ' TTYPE14 = 'VELY ' Spacecraft Velocity, Y-axis TFORM14 = 'E ' format of field TUNIT14 = 'kms ' = TTYPE15 = 'VELZ ' Spacecraft Velocity, Z-axis TFORM15 = 'E ' format of field TUNIT15 = 'kms ' TTYPE16 = 'EARTHLAT' MagField Model, Earth Latitude (Rad) TFORM16 = 'E ' format of field TUNIT16 = 'deg ' Unit TTYPE17 = 'EARTHLON' MagField Model, Earth Longitude (Rad) TFORM17 = 'E ' format of field 18

19 TUNIT17 = 'deg ' Unit = TTYPE18 = 'ALTITUDE' Spacecraft Altitude TFORM18 = 'E ' format of field TUNIT18 = 'm ' TTYPE19 = 'POINTGAL_LONG' Spacecraft Pointing Axis (Galactic Longitude) TFORM19 = 'E ' format of field TTYPE20 = 'POINTGAL_LAT' Spacecraft Pointing Axis (Galactic Latitude) TFORM20 = 'E ' format of field TTYPE21 = 'VELOCITYRA' Spacecraft Velocity Direction RA TFORM21 = 'E ' format of field TTYPE22 = 'VELOCITYDEC' Spacecraft Velocity Direction DEC TFORM22 = 'E ' format of field TTYPE23 = 'SUN_RA' Sun Position RA TFORM23 = 'E ' format of field TTYPE24 = 'SUN_DEC' Sun Position DEC TFORM24 = 'E ' format of field = TTYPE25 = 'MOON_RA' Moon Position RA TFORM25 = 'E ' format of field TTYPE26 = 'MOON_DEC' Moon Position DEC TFORM26 = 'E ' format of field TTYPE27 = 'SUN_ANGLE' Angle Between SUN and POINTING TFORM27 = 'E ' format of field TTYPE28 = 'MOON_ANGLE' Angle Between MOON and POINTING TFORM28 = 'E ' format of field TTYPE29 = 'RAM_ANGLE' Angle Between VELOCITY and POINTING TFORM29 = 'E ' format of field TTYPE30 = 'ELV' Angle Between EARTH LIMB and POINTING TFORM30 = 'E ' format of field TTYPE31 = 'OFFSET' Pointing OFFSET Angle TFORM31 = 'E ' format of field TTYPE32 = 'BKG_THETA' North going Equatorial Crossing Longitude TFORM32 = 'E ' format of field TTYPE33 = 'BKG_PHI' Orbit Phase Angle TFORM33 = 'E ' format of field TTYPE34 = 'TIME_SINCE_SAA' Time Since SAA Exit TFORM34 = 'E ' format of field 19

20 TTYPE35 = 'TIME_SINCE_CPM- PEAK' Time Since CPM PEAK count rate TFORM35 = 'E ' format of field TTYPE36 = 'CPM_RATE' CPM Count Rate TFORM36 = 'E ' format of field 3.8 LBT HK File File Name: AS1<OBSID>sxt_level2.lbt Where OBSID is observation ID Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions ORIGIN = 'ASTROSAT-SXT-L2' Configuration control CREATOR = 'SXT-L2 ' TELESCOP = 'ASTROSAT' INSTRUME = 'SXT ' CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) MJ = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time OBJECT = Source information block RA_PNT = Nominal pointing DEC_PNT = Nominal pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = 20

21 3.9.2 LBT HK Header FITS format XTENSION = 'BINTABLE' HDU 1 BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional Binary Table NAXIS1 = 180 Number of bytes per row NAXIS2 = Number of rows PCOUNT = 0 No group parameters (required keyword) GCOUNT = 1 One data group (required keyword) TFIELDS = 57 Number of columns EXTNAME = 'SXT-LBTHK SXT LBT HK DATA ORIGIN = 'SXT-L2 ' CREATOR = 'SXT-L2 ' HDUVERS = '1.0.0 ' HDUCLASS = 'OGIP ' LONGSTRN = 'OGIP 1.0' The OGIP long string convention may be used. CHECKSUM = HDU checksum DATASUM = Data checksum, ASCII encoded TTYPE1 = 'Time ' Time : Time stamp (sec since 1 Jan 2010) TUNIT1 = 's ' TFORM1 = 'D ' format of field TTYPE2 = 'Vod ' CCD Bias Drain Voltage TFORM2 = 'E ' format of field TTYPE3 = 'Vrd ' CCD Reference Bais Voltage TFORM3 = 'E ' format of field TTYPE4 = 'Vgr ' CCD guard Bias Voltage TFORM4 = 'E ' format of field TTYPE5 = 'Vid ' CCD ip diode Bias Voltage TFORM5 = 'E ' format of field TTYPE6 = 'Vog ' CCD op gate Bias Voltage TFORM6 = 'E ' format of field TTYPE7 = 'Vss_Vbk ' CCD substrate Bias Voltage TFORM7 = 'E ' format of field TTYPE8 = 'Reset_clock' CCD Reset Clock level TFORM8 = 'E ' format of field TTYPE9 = 'I_S_Clock' CCD IS Clock level TFORM9 = 'E ' format of field TTYPE10 = 'Offset ' Amplifier Offset Voltage TFORM10 = 'E ' format of field TTYPE11 = 'R_Clock ' CCD R Clock level TFORM11 = 'E ' format of field 21

22 TTYPE12 = 'IG_Clock' CCD IG Clock level TFORM12 = 'E ' format of field TTYPE13 = '+15V ' Analog Voltage +15V TFORM13 = 'E ' format of field TTYPE14 = '-15V ' Analog Voltage -15V TFORM14 = 'E ' format of field TTYPE15 = '+5VA ' Analog Voltage +5VA TFORM15 = 'E ' format of field TTYPE16 = '+5VD ' Digital Voltage +5VD TFORM16 = 'E ' format of field TTYPE17 = '-5VA ' Analog Voltage -5VA TFORM17 = 'E ' format of field TTYPE18 = 'Hop1_A ' Hop1 Coil A Voltage TFORM18 = 'E ' format of field TTYPE19 = 'Hop2_A ' Hop2 Coil A Voltage TFORM19 = 'E ' format of field TTYPE20 = 'Temp_EL-03' Temperature of card EL-03 TFORM20 = 'E ' format of field TTYPE21 = 'Temp_Bottom' Temperature of DC-DC tray TFORM21 = 'E ' format of field TTYPE22 = 'FPGA1_2.5V' FPGA1 core Voltage (2.5V) TFORM22 = 'E ' format of field TTYPE23 = 'FPGA1_3.3V' FPGA1 IO Voltage (3.3V) TFORM23 = 'E ' format of field TTYPE24 = 'FPGA3_2.5V' FPGA3 core Voltage (2.5V) TFORM24 = 'E ' format of field TTYPE25 = 'FPGA3_3.3V' FPGA3 IO Voltage (3.3V) TFORM25 = 'E ' format of field TTYPE26 = 'CCD_Temp_1' CCD Temperature_1 TFORM26 = 'E ' format of field TTYPE27 = 'CCD_Temp_2' CCD Temperature_2 TFORM27 = 'E ' format of field TTYPE28 = 'Camera_Temp' Camera Temperature TFORM28 = 'E ' format of field TTYPE29 = 'Cold_Figure' Cold Finger Temperature TFORM29 = 'E ' format of field 22

23 TTYPE30 = 'Camera_Vacuum' Camera Vacuum TFORM30 = 'E ' format of field TTYPE31 = 'Hop_Raw ' Hop Raw Voltage TFORM31 = 'E ' format of field TTYPE32 = 'TEC+ ' TEC Heating Mode Voltage TFORM32 = 'E ' format of field TTYPE33 = 'TEC- ' TEC Cooling Mode Voltage TFORM33 = 'E ' format of field TTYPE34 = '+12V ' +12V Supply Voltage TFORM34 = 'E ' format of field TTYPE35 = 'TEC_Raw ' TEC Raw Voltage TFORM35 = 'E ' format of field TTYPE36 = 'Bellow_Pressure' Bellow Pressure TFORM36 = 'E ' format of field TTYPE37 = 'Event_Threshold' Event Threshold TFORM37 = 'E ' format of field TTYPE38 = 'Set_CCD_Temp' Set CCD Temperature TFORM38 = 'E ' format of field TTYPE39 = 'CCD_Count_per_frame' CCD Counts TFORM39 = 'J ' format of field TTYPE40 = 'Command_Counter' Command Counter TFORM40 = 'I ' format of field TTYPE41 = 'Telescope_Door' Telescope Door TFORM41 = 'I ' format of field TTYPE42 = 'TEC_mode' TEC mode status TFORM42 = 'I ' format of field TTYPE43 = 'Crystal_12' Crystal 12 selection TFORM43 = 'I ' format of field TTYPE44 = 'LED_onoff' LED onoff selection TFORM44 = 'I ' format of field TTYPE45 = 'CCD_Read_LR' CCD Read LR selection TFORM45 = 'I ' format of field TTYPE46 = 'LBT_MR ' LBT mainredundant TFORM46 = 'I ' format of field TTYPE47 = 'Amp_Gain_HL' Amp Gain HL selection 23

24 TFORM47 = 'I ' format of field TTYPE48 = 'CCD_T1T2_active' CCD T1T2 active selection TFORM48 = 'I ' format of field TTYPE49 = 'FullWindow' CCD FullWindow TFORM49 = 'I ' format of field TTYPE50 = 'CCD_mode6' CCD mode6 onoff TFORM50 = 'I ' format of field TTYPE51 = 'CCD_mode5' CCD mode5 onoff TFORM51 = 'I ' format of field TTYPE52 = 'CCD_mode4' CCD mode4 onoff TFORM52 = 'I ' format of field TTYPE53 = 'CCD_mode3' CCD mode3 onoff TFORM53 = 'I ' format of field TTYPE54 = 'CCD_mode2' CCD mode2 onoff TFORM54 = 'I ' format of field TTYPE55 = 'CCD_mode1' CCD mode1 onoff TFORM55 = 'I ' format of field TTYPE56 = 'TEC_Control_Volt' TEC Control Voltage TFORM56 = 'E ' format of field TTYPE57 = 'AD ' Sync Value TFORM57 = 'I ' format of field 3.9 ORBIT File File Name: AS1<OBSID>sxt_level2.orb Where OBSID is observation ID Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions ORIGIN = 'ASTROSAT-SXT-L2' Configuration control CREATOR = 'SXT-L2 ' TELESCOP = 'ASTROSAT' INSTRUME = 'SXT ' CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data 24

25 DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) MJ = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time OBJECT = Source information block RA_PNT = Nominal pointing DEC_PNT = Nominal pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = ORBIT Header FITS format XTENSION = 'BINTABLE' Binary Table Extension BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional Binary Table NAXIS1 = Number of bytes per row NAXIS2 = Number of rows PCOUNT = 0 No group parameters (required keyword GCOUNT = 1 One data group (required keyword) TFIELDS = Number of columns EXTNAME = 'ORBIT Orbit Data ORIGIN = 'SXT-L2 ' CREATOR = 'SXT-L2 ' HDUVERS = '1.0.0 ' HDUCLASS = 'OGIP ' HDUCLAS1 = 'ORBIT ' LONGSTRN = 'OGIP 1.0' The OGIP long string convention may be used. CHECKSUM = HDU checksum DATASUM = Data checksum, ASCII encoded TTYPE1 = 'Time ' Time : Time stamp (sec since 1 Jan 2010) TUNIT1 = 's ' TFORM1 = 'D ' format of field TTYPE2 = 'X ' Position X TUNIT2 = 'm ' TFORM2 = 'E ' 4 Byte double TTYPE3 = 'Y ' Position Y TUNIT3 = 'm ' 25

26 TFORM3 = 'E ' 4 Byte double TTYPE4 = 'Z ' Position Z TUNIT4 = 'm ' TFORM4 = 'E ' 4 Byte double TTYPE5 = 'Vx ' Velocity X TFORM5 = 'E ' 4 Byte double TUNIT5 = 'kms ' TTYPE6 = 'Vy ' Velocity Y TFORM6 = 'E ' 4 Byte double TUNIT6 = 'kms ' TTYPE7 = 'Vz ' Velocity Z TFORM7 = 'E ' 4 Byte double TUNIT7 = 'kms ' TTYPE8 = 'Latitude' Latitude of spacecraft TUNIT8 = 'deg ' TFORM8 = 'E ' 4 Byte double TTYPE9 = 'Longitude' Longitude of spacecraft TUNIT9 = 'deg ' TFORM9 = 'E ' 4 Byte double TTYPE10 = 'Altitude' Altitude of spacecraft TUNIT10 = 'm ' TFORM10 = 'E ' 4 Byte double TTYPE11 = 'SemiMajor_Axis' Semi Major Axis of orbit TUNIT11 = 'm ' TFORM11 = 'E ' 4 Byte double TTYPE12 = 'Ecentricity' Ecentricity of orbit TFORM12 = 'E ' 4 Byte double TTYPE13 = 'Inclination' Inclination of orbit TUNIT13 = 'deg ' TFORM13 = 'E ' 4 Byte double TTYPE14 = 'ArgOfPerigee' Argument of Perigee TUNIT14 = 'deg ' TFORM14 = 'E ' 4 Byte double TTYPE15 = 'RAAN ' Right Accession angle of Ascending Angle TUNIT15 = 'deg ' TFORM15 = 'E ' 4 Byte double TTYPE16 = 'TrueAnomaly' True Anomaly of Spacecraft TUNIT16 = 'deg ' TFORM16 = 'E ' 4 Byte double 26

27 3.10 ATTITUDE File File Name: AS1<OBSID>sxt_level2.att Where OBSID is observation ID Primary Header FITS format SIMPLE = T HDU 0 BITPIX = 8 Number of bits per data pixel NAXIS = 0 Number of data axes EXT = T FITS dataset may include extensions ORIGIN = 'ASTROSAT-SXT-L2' Configuration control CREATOR = 'SXT-L2 ' TELESCOP = 'ASTROSAT' INSTRUME = 'SXT ' CHECKSUM = ASCII encoded HDU checksum DATASUM = Data unit checksum written in ASCII DATE = file creation date (YYYY-MM-DDThh:mm:ss UTC) DATE-OBS = Start date for data TIME-OBS = Start time for data DATE- = End date for data TIME- = End time for data TIMESYS = 'TT ' Time will be TT (Terrestrial Time) MJDREFI = (UTC) expressed in TT (integer part) MJDREFF = (UTC) expressed in TT (fractional part) MJ = JD TIMEZERI = Clock correction integer TIMEZERF = Clock correction fractional TIMEDEL = Time resolution TIMEUNIT = 's ' TSTARTI = integer portion of start time TSTARTF = fractional observation start time TSTOPI = integer observation stop time TSTOPF = fractional observation stop time OBJECT = Source information block RA_PNT = Nominal pointing DEC_PNT = Nominal pointing EQUINOX = J RADECSYS = 'ICRF ' Julian coordinate reference frame OBSERVER = Observation information block OBS_ID = ATTITUDE Header FITS format XTENSION = 'BINTABLE' Binary table Extension BITPIX = 8 8-bit bytes NAXIS = 2 2-dimensional Binary Table NAXIS1 = Number of bytes per row NAXIS2 = Number of rows PCOUNT = 0 No group parameters (required keyword) GCOUNT = 1 One data group (required keyword) TFIELDS = 6 Number of columns 27

28 EXTNAME = 'ATTITUDE Attitude Data ORIGIN = 'SXT-L2 ' CREATOR = 'SXT-L2 ' HDUVERS = '1.0.0 ' HDUCLASS = 'OGIP ' HDUCLAS1 = 'ATTITUDE' LONGSTRN = 'OGIP 1.0' The OGIP long string convention may be used. CHECKSUM = HDU checksum DATASUM = Data checksum, ASCII encoded TTYPE1 = 'Time ' Time : Time stamp (sec since 1 Jan 2010) TUNIT1 = 's ' TFORM1 = 'D ' format of field TTYPE2 = 'Q_SAT ' Spacecraft Quaternion (Order Q1, Q2, Q3, Q4), TFORM2 = '4D ' TTYPE3 = 'Roll_RA ' (deg) RA of the SC Roll(Pointing Axis) TFORM3 = '1D ' 8-byte Double TUNIT3 = 'deg ' Unit TTYPE4 = 'Roll_DEC ' (deg) DEC of the SC Roll(Pointing Axis) TFORM4 = '1D ' 8-byte Double TUNIT4 = 'deg ' Unit TTYPE5 = 'ROLL_ROT ' (deg) Rotation about SC Roll axis (Twist) TFORM5 = '1D ' 8-byte Double TUNIT5 = 'deg ' Unit TTYPE6 = 'ATD_STATUS' Attitude Status flag, TFORM6 = '8X ' One byte value 4. References [1] Astrosat Data Pipeline Requirements Document Version 2.5, May 09 [2] Astrosat (SXT) Data Pipeline Processing Document, AST-SXT-SOFTWARE-004, Nov [3] Astrosat Level1 Interface Control Document, ASTROSAT-GS-ICD-LEVEL-1VER1.5, August [4] Observation Identification and Data File naming convention for the ASTROSAT mission, by Dipankar Bhattacharya, Nov 2010, Version 0.8 (draft). 28