[fitsbits] FIT Keyword data dictionaries

[Doug Mink]

I agree with Tom Kuiper that the TEL prefix is better than the SITE, as the
word SITE sounds like it could refer to several telescopes and TELESCOP is
already being used as a telescope name.  I also agree with Steve Allan that
we should be clear which coordinates we are using.  Mark Calabretta's suggested
Cartesian coordinates would best be used to specify a spacecraft position
or maybe radio telescope positions for VLBI observations, especially if some
of the stations are not on the earth's surface.  in those cases, a center,
such as earth, earth-moon barycenter, sun, solar system barycenter or other
planet center, must be specified as well.  In the FITS tradition, we should
keep the telescope coordinates as human-understandable as possible.

TELESCOP= 'flwo1.2m'           / TELESCOPE NAME
TELGLONG=             110.8748 /LONGITUDE, DEGREES WEST OF ZERO
TELGLAT =              31.6809 /LATITUDE, DEGREES
TELELEV =               2320.0 /ELEVATION, METERS

My software which uses the position for computation of radial velocity
corrections is in IRAF, and I use its parser to automatically convert
sexigesimal numbers to decimal when it encounters them, so the following
should give the same result:

TELESCOP= 'flwo1.2m'
TELGLONG= '+110:52:39.0'       /LONGITUDE, DEGREES WEST OF ZERO
TELGLAT = '+31:40:51.4'        /LATITUDE, DEGREES
TELELEV =               2320.0 /ELEVATION, METERS

-Doug Mink