[daip] precess images in AIPS

[Eric Greisen]

Saskia Prins writes:

 > I would like to compare 2 VLA maps, overplot contours, make spectral index
 > maps, etc.  Image nr 1 (from 1992) is in 1950 coordinates, image nr 2
 > (from 1996) in 2000 coordinates.  I was hoping OHGEO would do the
 > precession for me, but it does not.  Is there a task in AIPS for
 > precessing of the WCS header information, (similar to tprecess in IRAF) ?  
 > I looked through the index, but found nothing obvious.
 > 

There is a verb in aips called EPOSWTCH which will change between
epochs in the header.  You may than have to shift and rotate the image
to make it line up.  OHGEO, HGEOM are the best a that.

The task REGRD may be better for the two operations done at the same
time.

Eric Greisen