[daip] [!5978]: aips - Aligning two images

[Eric Greisen]

Eric Greisen updated #5978
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       Staff (Owner): Eric Greisen (was: -- Unassigned --)
                 Due: - Cleared - (was: 19 January 2015 08:17 PM)

Aligning two images
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           Ticket ID: 5978
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/5978
           Full Name: Chris De Pree
               Email: cdepree at agnesscott.edu
             Creator: User
          Department: AIPS Data Processing
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 14 January 2015 08:04 PM
             Updated: 14 January 2015 09:01 PM
      Resolution Due: 23 January 2015 08:04 PM (8d 23h 2m)



The question I have is why did HGEOM not work.  I would
guess that the coordinates in one of the images are not
correct (an optical image?).  Optical images often come 
to us in FITS with a full CD matrix including skew.  The
history file will show you if that was the case.  If so, you 
should use DSKEW on the image before doing your HGEOM.
That might help with the coordinates.  LGEOM will of course 
allow you to do a shift fairly reasonably although it should then
get the coordinates offset if HGEOM thought that it had aligned
them.

Eric Greisen




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