[daip] [!7565]: AIPS - IMAGR data selection

[Michael Bietenholz]

Michael Bietenholz updated #7565
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IMAGR data selection
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           Ticket ID: 7565
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/7565
           Full Name: Michael Bietenholz
               Email: mbieten at yorku.ca
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 08 November 2015 07:12 AM
             Updated: 09 November 2015 01:44 PM
      Resolution Due: 18 November 2015 12:00 AM (8d 10h 15m)



I think I figured out what the problem is:

According to IMHEAD, the random parameters on this data set are:
Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  TIME1  SUBARRAY  INTTIM  GATEID  ANTENNA1  ANTENNA1  ANTENNA2

Note that there are *two* ANTENNA1's.  What happens as far as I can tell, after some poking in debug, is that the first of the ANTENNA1's is always 1, while the second one corresponds to the true antenna1.    IMAGR presumably does some selection on the first of the ANTENNA1's and thus finds no data whenever it is de-selected.

I'm not sure how my data set got to be this way:  Here's a trace of its random params (FITTP and FITLD were both 31DEC15 unless noted)

The original AIPS file:       UU VV WW  TIME1  SUBARRAY SOURCE  FREQSEL  INTTIM  GATEID  ANTENNA1  ANTENNA2
FITS file from above:         UU VV WW  DATE*2 BASELINE SOURCE  FREQSEL  INTIIM  GATEID  ANTENNA1
FITS file reloaded into AIPS: UU VV WW  TIME1  SUBARRAY SOURCE  FREQSEL  INTTIM  GATEID  ANTENNA1  ANTENNA1 ANTENNA2
 " but using 31DEC14          UU VV WW  TIME1  BASELINE SOURCE  FREQSEL  INTTIM  GATEID  ANTENNA1

(sorry the above all lined up nicely when I typed it in a fixed font window - I have no idea whether it will by the time you see it)

I attach a small FITS file corresponding FITS stage above.

So somehow in the passage through FITTP/FITLD it acquired an extra ANTENNA1.  The 31DEC15 FITLD was a version from MNJ 2015 Oct ~23,while the FITTP was around 2015 Oct ~15

My question is how can I get rid of this spurious random parameter again?

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