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

   

Headers

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:

INSTRA

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

Header keyword Contents Comment

SIMPLE  = T /

BITPIX  = 8 /

NAXIS  = 0 /

EXTEND  = T /

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

 

Records

 

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 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

 

Notes

1

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.

2

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

3

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.

4

See section 9.4.2 for a discussion of SWAALINE and SWAASCNT.

5

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 .

6

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

7

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

9.4.2 SWAALINE and SWAASCNT

    

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

. . . . .

 

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.