[daip] [!8707]: AIPS - Can IMEAN ‘histogram’ RMS be written into ACTNOISE?

[Robert Gray]

Robert Gray updated #8707
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Can IMEAN ‘histogram’ RMS be written into ACTNOISE?
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           Ticket ID: 8707
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/8707
           Full Name: Robert Gray
               Email: roberthansengray at gmail.com
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): -- Unassigned --
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 20 July 2016 09:27 PM
             Updated: 20 July 2016 09:27 PM
                 Due: 22 July 2016 09:27 PM (2d 0h 0m)
      Resolution Due: 28 July 2016 09:27 PM (8d 0h 0m)



Hi!

I’m working on an AIPS procedure to run SAD on each channel of an image cube, using the RMS for each channel (rather than the global RMS in ACTNOISE) for both (1) setting a series of successively declining thresholds, and (2) getting the RMS value used included in SAD’s output report.  

The method I’ve arrived at is to run IMEAN on each channel and have it write the RMS into ACTNOISE, then run SAD which automatically reports ACTNOISE in its print file (so I can calculate SNR later) and which I use to set threshold levels.   Seems to work fine!  It nearly doubles execution time, but I can live with that if necessary.  I could not make PUTHEAD write IMSTAT’s ‘pixstd’ into the header ACTNOISE, which might have been faster, and I could not PUTHEAD a -1 or 0 into ACTNOISE to force SAD to calculate an RMS for each channel (as you seemed to have suggested).  

One drawback is that strong sources jack up the RMS reported by IMEAN and written into ACTNOISE.  Is there a way to get the ‘histogram’ RMS written into ACTNOISE instead?

Best wishes,

Bob Gray


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