[daip] [!8799]: AIPS - Cookbook and BPASS for VLBI data

[Michael Bietenholz]

Michael Bietenholz updated #8799
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Cookbook and BPASS for VLBI data
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           Ticket ID: 8799
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/8799
           Full Name: Michael Bietenholz
               Email: mbieten at yorku.ca
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): -- Unassigned --
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 08 August 2016 10:08 PM
             Updated: 08 August 2016 10:08 PM
                 Due: 10 August 2016 10:08 PM (2d 0h 0m)
      Resolution Due: 16 August 2016 10:08 PM (8d 0h 0m)



The cookbook, chapter 9 ("reducing VLBI Data"; version 31-December-2015) suggests first obtaining single-band delays using VLBAPCOR (and possibly FRING).  It then suggests running BPASS *with DOCALI=-1* (page 9-40).  That seems wrong to me - running BPASS w/ DOCALI=-1 will have the effect of putting the single-band delay corrections into the BP table which would then make the calibration derived by VLBAPCOR wrong.  

I would have thought one would run BPASS with DOCALI=1 to first apply the single-band delay corrections and then solve for any residual bandpass effects.

Am I confused?

I did try this as recommended by the Cookbook, and found what that after running both VLBAPCOR and BPASS, then POSSM plot shows the phases to be flattened within each IF with either DOCALI=1 or DOBAND=1, but with both of them they phase-vs-frq slope within an IF is *not* corrected.

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