image orientation on the screen

[Doug Mink]

Mike Newberry <mnewberry at axres.com> writes:
> It would be really useful if there were two keywords that would go
> into an image header at the point of origin that could later be used
> to give the correct display in the "mirror" sense.

In my world coordinate setting software, I have had to deal with image
rotation and mirroring on an image-by-image basis.  I, too, would
like to have some keywords to specify mirroring (XREVERSE and YREVERSE
sound like the right idea) and position angle of north (NORTHPA?)
standardized as either before or after mirroring.  For the ground-based
optical telescopes with which I have been dealing, these keyword values
stay constant for at least the duration of a run.

-Doug Mink
 Telescope Data Center
 Harvard-Smithsonian Center for Astrophysics