[daip] [!4536]: aips - SNSMO in VLMB mode sometimes breaks the relationship between phase(per IF) and delay

[Michael Bietenholz]

Michael Bietenholz updated #4536
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              Status: Open (was: Response Overdue)

SNSMO in VLMB mode sometimes breaks the relationship between phase(per IF) and delay
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           Ticket ID: 4536
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/4536
           Full Name: Michael Bietenholz
               Email: mbieten at yorku.ca
             Creator: User
          Department: AIPS Data Processing
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 19 February 2014 06:58 PM
             Updated: 25 February 2014 02:46 PM
                 Due: 27 February 2014 02:46 PM (2d 0h 0m)
      Resolution Due: 04 March 2014 07:14 PM (7d 4h 28m)



If it helps, I think what VLMB mode is supposed to do is something like this

1)  rotate all the phases to IF1 according to the SN-table MBD 
2)  average across IFs and smooth in time as requested
3)  rotate phases back to their individual IFs according to the smoothed MBD

I've only ever used it in VLMB mode on SN tables that were produced by FRING w/ DPARM(5)=1, where the entries for phase are functionally related across the IFs.  Its probably dangerous to use it in a case where the SN-table phase solutions in the individual IFs are in fact independent.

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