[fitsbits] INSTRUME and TELESCOP

[Steve Allen]

On Wed 2009-05-06T15:27:04 -0400, Bob Garwood hath writ:
> The few successful attempts I'm
> aware of typically involve steps like "I know this SDFITS file came from
> aips++, so I need to do this to that field to make sense of it."  It
> would be ideal if those types of steps wouldn't be necessary.

Alas, in many cases the initial requirements on keyword values were
somewhat lax (if they existed at all).  The only way to make that not
necessary is to fight the battles of adding bits to the standard.

In order to avoid utter confusion that usually requires adding new,
previously unused keywords to the standard in order to require that
they may only have values with specific, precise characteristics.

This is the battle that is in progress right now for the time-related
keywords of FITS WCS paper 5.  It is particularly tricky to deal with
keywords that relate to star/end/duration of an observation or
exposure.  There are many keywords already in use by various agencies
with various meanings.  "All the good names are already taken", so
the paper is suggesting things like XPOSURE.

I'll close with this repeated plea that everyone from radio to gamma
ray look at the keywords related to exposure times in the draft of
FITS WCS 5
http://hea-www.harvard.edu/~arots/TimeWCS/
and reply to the fitswcs list.

--
Steve Allen                 <sla at ucolick.org>                WGS-84 (GPS)
UCO/Lick Observatory        Natural Sciences II, Room 165    Lat  +36.99855
University of California    Voice: +1 831 459 3046           Lng -122.06015
Santa Cruz, CA 95064        http://www.ucolick.org/~sla/     Hgt +250 m