[daip] [!7748]: AIPS - Wrong definition of position angle in IRING

[Eric Greisen]

Eric Greisen updated #7748
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Wrong definition of position angle in IRING
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           Ticket ID: 7748
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/7748
           Full Name: Luis Rodriguez
               Email: l.rodriguez at crya.unam.mx
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 19 December 2015 09:15 PM
             Updated: 22 December 2015 10:00 PM
      Resolution Due: 30 December 2015 12:00 AM (7d 2h 0m)



I put in a debug statement in the code to tell me
the projected radius of a pixel I selected on the end
of the major axis.  That radius should be essentially
the unprojected radius.  It is only if I put in the position
angle known to be -60.1 degrees.  In all others it is
fore-shortened by incorrect geometry.  So I think
that the task is okay in position angle.  It got scales
wrong by cos(inclination) and did not honor fixed scale
plotting and insisted on writing out all the points to
the message file.

I have decided that the correct position angle drops
more rapidly (cparm(5)=1) but has a long tail out to the
full radius compared to a position angle 90 degrees off.
With cparm(5)=2 the cumulative plot rises most slowly
with the correct position angle and gains values all the
way to the actual radius of the major axis.

I will put back the corrections today probably.

Eric Greisen




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