[daip] [!11333]: AIPS - AIPS UVSUB doesn't work with multiscale CLEAN images and CMETH='GRID'

[Eric Greisen]

Eric Greisen updated #11333
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              Status: Closed (was: Open)

AIPS UVSUB doesn't work with multiscale CLEAN images and CMETH='GRID'
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           Ticket ID: 11333
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/11333
                Name: Michael Bietenholz
       Email address: mbieten at yorku.ca
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Closed
            Priority: Default
      Template group: Default
             Created: 05 December 2017 01:02 PM
             Updated: 19 January 2018 09:17 PM

I found it.  The Q routine that handle the modeling has a scalefactor to apply to the input data.  It was 0 for MODL so it zeroedthe original visibilities (good), but on the subsequent fields itzeroed what was then in the accumulators (bad).;  Setting that scalefactor to 1 for fields > 1 fixes things.  I note in my test data thatGRID made a much noisier model at longer spacings than the DFTone.  GRID is never wonderful - just faster.Eric Greisen


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