[daip] [!14061]: AIPS - PCAL with SPECTRAL=1

[Lynn Matthews]

Lynn Matthews updated #14061
----------------------------

PCAL with SPECTRAL=1
--------------------

           Ticket ID: 14061
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/14061
                Name: Lynn Matthews
       Email address: lmatthew at haystack.mit.edu
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): -- Unassigned --
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template group: Default
             Created: 17 June 2019 02:16 PM
             Updated: 17 June 2019 02:16 PM
           Reply due: 19 June 2019 02:16 PM (2d 0h 0m)
      Resolution due: 12 March 2022 07:00 PM (999d 5h 44m)

I have some questions on running PCAL.Having done a "continuum" polarization calibration that appears to have been successful, I have been attempting to use PCAL to fit for the expected variation in the EVLA polarizers with frequency.I set SPECTRAL=1 and have tried a variety of values for INTPARM(1,2,3). However,  the results never look sensible.First, there are always jumps in amplitude and phase at the boundaries of the ICHANSEL cutoffs. Second, it appears to be fittingnoise wiggles rather than what I would imagine for actual instrumental variations with frequency. I attach some sample plots.So some questions:(1) Are there recommended values for INTPARM?
(2) Should I use both SMOOTH and INTPARM? (I do not fully understand how they differ)
(3) Given that my band is narrow, might I be better off to ignore this correction all together?Thanks,Lynn Matthews

------------------------------------------------------
Staff CP:  https://help.nrao.edu/staff
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listmgr.nrao.edu/pipermail/daip/attachments/20190617/ffc9101a/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PCAL_SPECTRAL_sample.png
Type: image/png
Size: 77114 bytes
Desc: not available
URL: <http://listmgr.nrao.edu/pipermail/daip/attachments/20190617/ffc9101a/attachment-0001.png>