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9.4 Auto-Analysis Results (AAR) files

There is one file in this section:

SWAA SWS Auto-Analysis Results

9.4.1 SWS Auto-Analysis Results



The AAR files contain primary headers described in Table 9.11. In this table example information is used to fill the header.

Most keywords are self explanatory, or have been described above. Those that are not include:

This, along with INSTDEC and INSTROLL, are described in the ISO DUM .

Header keyword Contents Comment
BITPIX  = 8 /
NAXIS  = 0 /
ORIGIN  = 'ESA ' / European Space Agency
TELESCOP = 'ISO ' / Infrared Space Observatory
INSTRUME = 'SWS ' / Instrument used
COMMENT   SWS Auto Analysis Results
FILENAME = 'SWAA26400248' / File name in ISO archive
DATE  = '17/10/95' / Creation date 95/290
FILEVERS = '0399 ' / Version ID in ISO archive
OLPVERS  = 'LATEST ' / SOC OLP system version
USERNAME = 'JSTERNBE' / Unofficial data product
OBJECT  = 'TEST_OBJ' / Target ID as given by proposer
OBSERVER = 'KLEECH' / Proposer ID in ISO Mission DB
EQUINOX  = 2000.0 / Equinox
TMRATE  = 32 / Telemetry rate in Kbps (Kbits/sec)
EOHAUTCS = '96166223020' / Approx. UTC of start of observation
EOHAUTCE = '96166223818' / Approx. UTC of end of observation
EOHAAOTN = 'S07 ' / AOT name
EOHAPLID = 'KL_TEST' / Proposal ID
EOHAOSN  = '48 ' / Observation sequence number
EOHAPSN  = '0 ' / Pointing sequence number
EOHAPCAT = '1 ' / Proposal category
EOHACIND = ' ' / Calibration indicator
EOHATTYP = '2 ' / Target type
ATTUTCSL = '96166222532' / UTC of start time of slew to intended target
ATTUTCS  = '96166222627' / UTC of time of first arrival at intended target
ATTOTFTH = 10.0 / On-target flag threshold (arc secs)
ATTRA  = 102.66 / Intended Right Ascension of instrument viewing


ATTDEC  = 27.8 / Intended DEClination (with ATTRA)
ATTTYPE  = 'P ' / Type of attitude operation (P/R/T)
ATTGUIDE = 150002 / Guide star reference number
ATTSAANG = 115.9 / Solar aspect angle (degrees)
ATTERROR = 2 / CONTINGEncy flag(0=success; 1=target not acq'd)
TREFUTC1 = 235175420 / UTC (whole seconds since 01-01-1989)
TREFUTC2 = 8505250 / UTC (remaining fraction of second)
TREFUTK  = 1857816480 / ISO Uniform Time Key (UTK)
TREFITK  = 1857816480 / ISO INSTRUMENT Time Key (ITK)
TREFITKU = 0.04166666666667 / ITK unit length in seconds
TREFCOR1 = 235175420 /UTC of 1st reference time
TREFHEL1 = -253.41 /Heliocentric correction +(s) at TREFCOR1
TREFDOP1 = -13.92 /ISO velocity towards target (km/s) at TREFCOR1
TREFCOR2 = 235175659 /UTC of 2nd reference time
TREFHEL2 = -253.40 /Heliocentric correction +(s) at TREFCOR2
TREFDOP2 = -13.93 /ISO velocity towards target (km/s) at TREFCOR2
TREFCOR3 = 235175898 /UTC of 3rd reference time
TREFHEL3 = -253.39 /Heliocentric correction +(s) at TREFCOR3
TREFDOP3 = -13.94 /ISO velocity towards target (km/s) at TREFCOR3
INSTRA  = 102.66474 /Reference instrument J2000 right ascension (deg)
INSTDEC  = +27.81240 /Reference instrument J2000 declination (deg)
INSTROLL = 318.89 /Reference instrument J2000 roll angle (deg)
VERS1  = '0399/SWSP26400248' / Version ID of each input file
VERS2  = '0388/SC03' / Version ID of each input file
VERS3  = '0388/SC21_1' / Version ID of each input file
VERS4  = '0388/SC21_2' / Version ID of each input file
VERS5  = '0388/SC21_4' / Version ID of each input file
VERS6  = '0388/SC21_8' / Version ID of each input file
VERS7  = '0388/SC13' / Version ID of each input file
VERS8  = '0388/SC25_1A' / Version ID of each input file
VERS9  = '0388/SC25_3A' / Version ID of each input file
VERS10  = '0388/SC25_5B' / Version ID of each input file
Table 9.11: AAR primary headers




The AAR file contains records with the fields described in Table 9.12. In the FITS file they are defined in the binary header.


Field name Number Format Unit Comment
SWAAWAVE  1 R*4 tex2html_wrap_inline6866 Wavelength of data point
SWAAFLUX  1 R*4 Jy Flux
SWAASTDV  1 R*4 Jy Standard deviation of the flux
SWAATINT  1 I*4 sec Total integration time
SWAADETN  1 I*4 detector number
SWAAITK  1 I*4 SWS instrument time key
SWAAUTK  1 I*4 ISO uniform time key
SWAARPID  2 I*1 raster point id
SWAASPAR  2 I*1 spare
SWAALINE  1 I*4 line number
SWAASDIR  1 I*4 scan direction
SWAASCNT  1 I*4 scan number
SWAASTAT  1 I*4 status word
SWAAFLAG  1 I*4 flag word
Table 9.12: AAR file



The total integration time, SWAATINT, is the total time taken into account to calculate this data point. See section 8.3.8 for a definition of this.

SWAADETN can be used to find which detector observed each point by referring to table 3.1.

SWAARPID, the raster  point id, is copied over from the GPSCRPID  in the SPD. It is always (1,1) (unless a Solar System Object is being tracked) (but see section 2.9, ``Caveats'', point 6), as SWS has no raster AOTs, but is included so that the format of SWS AA is compatible with LWS AA.

See section 9.4.2 for a discussion of SWAALINE and SWAASCNT.

SWAASDIR is used to identify if the datapoint is from an up-scan (1) or a down scan (-1). 0 is undefined (and don't use the data). See section 8.3.6 for a definition of up-down scans .

SWAASTAT is copied over from SWSPSTAT . For a description of this see Table 9.7.

SWAAFLAG is copied over from SWSPFLAG . For a description of this see Table 9.8.



SWAALINE and SWAASCNT are both counts of the valid data present in an AAR.

SWAALINE is a count of the valid ranges in a dataset. For AOT 1 , it is filled with the AOT band number. For an AOT 2  observing X lines it will count from 1 to X, with 0 reserved for any datapoints not associated with a line. Note that the datapoints associated with SWAALINE set to, e.g. 1, may not correspond to the first entered line number in your AOT as the logic may re-arrange them to increase efficiency. For AOT 6  it counts the number of scans, for an example see table 9.13.


Operation line number for detector band
1 2 3 4
REF 1 2 3 4
SCAN UP 5 6 7 8
REF 9 10 11 12
SCAN DOWN 13 14 15 16
REF 17 18 19 20
. . . . .
Table 9.13: Line number against detector band


Note that the scans may be different for a different AOT 6 operation.

SWAASCNT has nothing to do with the number of scans required for an AOT. It is a count of the number of lines/bands containing requested (i.e. what was requested in the AOT) data, starting with 1. Any data outside the requested ranges will have SWAASCNT set to 0. Note that even if SWAASCNT is greater than 0, the flag and status word should be checked to ensure the data is okay. For AOT 1 SWAASCNT is filled with 1.

The decision whether to increment SWAALINE or SWAASCNT depends on whether a scan starts and ends at the same grating position as the preceeding scan. Initially both are set to one. If a scan starts and ends at the same grating position as the preceeding scan the line counter is not incremented but the scan counter is. If the wavelength range is different the line counter is incremented and the scan counter is (re-)set to one.

A slight problem exists in the counting of SWAALINE in that the counter can count up too much, resulting in a higher count than the number of lines. This will be fixed in a later release of OLP.

next up previous contents index
Next: 9.5 Calibration-G files Up: 9 Product Description Previous: 9.3 Standard processed (SPD)

K. Leech with contributions from
the SWS Instrument Dedicated Team (SIDT)
and the SWS Instrument Support Team (SIST)