Read Pointing Information from Attitude Files

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Description:

1. Create temporary versions of the attitude files with the first and last 100 rows removed. Files with fewer than 300 rows are left as-is. This is to remove the effects of the spacecraft's slew to and away from the object.

2. Calculate the mean RA and Dec for each trimmed attitude file.

3. If there is more than one attitude file, make sure that the mean pointings for all the trimmed files concur to within 1 arc minute. If they do not, abort the script.

4. Calculate the mean pointing for each untrimmed attitude file. These values are not used in the processing, but are recorded in the job log for future reference.

5. Merge the trimmed attitude files into one big file.

6. Calculate the mean pointing (RA, Dec, and roll angle) from the merged, trimmed attitude file. This pointing information is used in the rest of the processing. If there was any problem, then extract the RA and Dec from the attitude file FITS header. If even this can't be done, then set the troublesome value(s) to zero.

7. Calculate the galactic coordinates and Euler angles for the mean pointing.

Associated Routines:

• attitude (ftools)
• objdist (stools)
• fmerge (ftools)

Input Files:

• FRF Attitude files: fa[date]_[start].[end]

Output Files:

• Job log: ad[sequence].joblog