[daip] Pbcor

[Eric Greisen]

Marina Alexandrovna Kounkel wrote:
> Hello,
> 
> We are producing 4 fields for each object using imagr. Then we are trying to use pbcor to correct photometry for the primary beam, however, it treats each quadrant as an individual image while doing so. If we were to explicitly specify observed ra and dec of the pointing center within the header of the image, pbcor works fine, but as it is, this information appears to be missing. What exactly should we do?

The pointing position should not be missing from image headers.  Where 
did these images come from and I suspect I may even need to know when?
We are trying to carry the pointing position around carefully now but 
this was treated badly in the past.  The code in IMAGR certainly tries 
to copy the pointing position from the UV file to the image.  But I 
remain a bit uncertain about whether this all works.

Note that you can use PUTHEAD to correct the headers (try GETHEAD to see 
what is in the parameters before you do).  IMHEADER will show a pointing 
position only if it is not the reference position (and not 0,0).

Eric Greisen