[daip] Question

[Eric Greisen]

Mark Calabretta writes:
 > 
 > On Thu 2007/10/04 19:54:36 +0200, Jorge Ariel Combi wrote
 > in a message to: Mark.Calabretta at atnf.csiro.au
 > 
 > >I have a FITS image in galactic coordinates and I need put this image in 
 > >equatorial coordinates (J2000). Can you tell me what AIPs task should I use?
 > 
 > Dear Jorge,
 > 
 > Ideally you should simply be able to modify the FITS header
 > appropriately, by resetting the CRVALia and LONPOLEa cards, but I'm
 > not sure whether AIPS understands LONPOLEa. 
 > 
 > I remember writing an AIPS task called REGRD which could do the job,
 > though it would have to regrid the image which is not the best solution.
 > 
 > However, it's a long time since I've used AIPS, Eric Greisen (cc'd) may
 > have a better idea.

It depends on what form your image has.  If it is a simple projective
image (e.g. -SIN, -TAN) then the AIPS verb CELGAL is all you need.  As
Mark says, AIPS does not understand any/all of the new WCS.  REGRD is
present if you have a full-sky -AIT for example.  Actually at that
point you probably need OHGEO or HGEOM.

Eric Greisen