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Subsections



D.13 Instrument Reference Pointing History (IRPH)

This file details the complete set of reference sky positions that apply to an observationD.3. A staring observation has one record per aperture; a raster observation has one record per raster point per raster. As the name suggests, these directions provide the reference points for the calculation of the OTF in the IIPH.

D.13.1 Primary header

The IRPH file contains a primary header with the fields described in Table D.32. In this example non-mandatory fields are filled with example values.

Table D.32: IRPH primary header.
Keyword Value Description
SIMPLE = T / File does conform to FITS standard
BITPIX = 8 / Number of bits per data pixel
NAXIS = 0 / Number of data axes
EXTEND = T / FITS dataset may contain extensions
ORIGIN = 'ESA ' / European Space Agency
TELESCOP = 'ISO ' / Infrared Space Observatory
COMMENT   Instrument Reference Pointing History
FILENAME = 'IRPH08300207' / File name in ISO archive
DATE = '12/02/96' / Creation date
FILEVERS = '0518 ' / Version ID in ISO archive
OLPVERS = 'OLP_242 ' / SOC OLP system version
CALGVERS = 'CALG_31 ' / SOC OLP CAL-G files version
USERNAME = 'PIPELINE' /
CREATOR = 'DERIVE_IPH v2.0' / Application that created the file
INSTRUME$^1$= 'CAM ' / Instrument identifier
ATTRA$^2$ = 266.56054 / Intended Instrument J2000 Right Ascension (degrees)
ATTDEC$^2$ = +62.45108 / Intended Instrument J2000 Declination (degrees)
ATTTYPE$^3$ = 'R ' / Type of attitude operation
ATTOTFTH = 10.0 / On-target threshold (arcsec)
ATTRNPTS = 3 / Number of points per raster line
ATTRNLNS = 3 / Number of raster lines
ATTRDPTS = 92 / Distance between adjacent points (arcsec)
ATTRDLNS = 92 / Distance between adjacent lines (arcsec)
ATTRORIE = 1 / Raster orientation flag (0 or 1)
ATTRROTA = 0.0 / Rotation of raster pattern (degrees)
ATTGUIDE = 93715 / Guide star reference number
ATTSAANG = 88.7 / Solar aspect angle (degrees)
ATTERROR = 0 / 0=OK, 1=target not acquired,
    / 2=No STR/QSS misalignment
ATTMISQ1 = 0.0000000 / STR/QSS misalignment quaternion Q(1)
ATTMISQ2 = -0.0004555 / STR/QSS misalignment quaternion Q(2)
ATTMISQ3 = -0.0002231 / STR/QSS misalignment quaternion Q(3)
ATTMISQ4 = 0.9999999 / STR/QSS misalignment quaternion Q(4)
ATTINSQ1 = 0.0000000 / QSS/Instrument alignment quaternion Q(1)
ATTINSQ2 = -0.0000181 / QSS/Instrument alignment quaternion Q(2)
ATTINSQ3 = 0.0012427 / QSS/Instrument alignment quaternion Q(3)
ATTINSQ4 = 0.9999992 / QSS/Instrument alignment quaternion Q(4)
INSTRA = 266.13155 / Reference instrument J2000 right ascension (degrees)
INSTDEC = +62.42157 / Reference instrument J2000 declination (degrees)
INSTROLL = 127.70 / Reference instrument J2000 roll angle (degrees)
CINSTRA = 266.13155 / Corrected reference instrument J2000 right ascension (degrees)
CINSTDEC = +62.42157 / Corrected reference instrument J2000 declination (degrees)
CINSTROL = 127.70 / Corrected reference instrument J2000 roll angle (degrees)
VERS1 = '0518/EOHA083' / Version ID of each input file
VERS2 = '0518/EOHI083' / Version ID of each input file
VERS3 = '0515/APPH083' / Version ID of each input file
VERS4 = '0456/IFPG' / Version ID of each input file
VERS5 = '1047/ISTR' / Version ID of each input file
VERS6 = '1047/SOLUN' / Version ID of each input file
VERS7 = '1350/ORBIT' / Version ID of each input file


Notes:
1.
During spacecraft activation the INSTRUME keyword refers to the QSS.
2.
Intended RA & Dec of instrument viewing direction in degrees. For SWS it refers to whichever slit is being used, for ATTYPE `R' or `T' it refers to the centre of the raster pattern.
3.
Type of attitude operation; `P' for fine pointing; `R' for raster; and `T' for SSO tracking.

D.13.2 Records

Each record contains the fields described in Table D.33.

Table D.33: IRPH records.
Keyword Number Format Description
RA0 1 R8 Raster centre reference right ascension, in degrees
DEC0 1 R8 Raster centre reference declination, in degrees
ROLL0 1 R8 Raster centre reference roll angle, in degrees
SPARE 1 I1 Spare space
TYPE 1 A1 Type of pointing operation
RPID 2 I1 Raster pointer ID
UTC$^1$ 1 I4 UTC of start of observation, in seconds, since 1989.0
STRQ 4 R8 Star-Tracker point quaternion
INSQ 4 R8 QSS/aperture alignment quaternion
RPQ 4 R8 Raster point quaternion
RA$^2$ 1 R8 Uncorrected raster point reference right ascension, in degrees.
      It is derived from the APPH file
DEC$^2$ 1 R8 Uncorrected raster point reference declination, in degrees
ROLL$^2$ 1 R8 Uncorrected raster point reference roll angle, in degrees
CORQ 4 R8 Raster point correction quaternion
CRA 1 R8 Corrected raster point reference right ascension, in degrees
CDEC 1 R8 Corrected raster point reference declination, in degrees
CROLL 1 R8 Corrected raster point reference roll angle, in degrees
OTFT 1 R4 On-target flag threshold, in arcsec
APERTURE$^3$ 1 C2 Instrument/aperture combination (e.g. `S3')
FILLER 2 I1 For alignment


Note:
1.
The UTC start time in the IRPH is the time at which the satellite starts to slew and point towards the raster point in question.
2.
RA, DEC and ROLL are all measured in degrees -- RA is not measured in hh:mm:ss. See the definition in Appendix F of RA, DEC and ROLL.
3.
During activation the APERTURE keyword contains `Z0', the aperture of the QSS.


next up previous contents index
Next: D.14 ISO Star-Tracker Calibration Up: D. Satellite Files Previous: D.12 Instrument Instantaneous Pointing
ISO Handbook Volume I (GEN), Version 2.0, SAI/2000-035/Dc