[fitswcs] RADESYS = 'GAPPT'

[Steve Allen]

On Wed 2011-03-16T11:38:00 -0700, Rob Seaman hath writ:
> Which is all to say that another possibility is to ignore the
> telescope pointing and run the astrometry.net code from a
> postprocessing command.

That is the next step, but instruments with small FOV will benefit
from a good initial WCS.

Still, there is value in recording the telescope pointing.
An archive full of images with telescope-based coordinates and
post-processed astrometric coordinates should be a useful engineering
tool for diagnosing the pointing system.

> For other instrumentation such as multi-object spectrographs, the
> notion of telescope pointing is quite a bit different.  What does it
> mean for a bench spectrograph to be "on-target"?

In the case of slitmask-based spectrographs each is either
astrometrically on-target or not providing object data.

--
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