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Re: OGIP/93-013 - A list of standard strings for HE missions,instruments & filters.

We are in the process of thinking about FITS data file formats for data
from our ALEXIS satellite. We would like to propose a set of keywords for
the six EUV/ultrasoft x-ray telescopes on our satellite. The detectors and
filters are fixed for each of the telesopes. The questions we have are:

1. What is the maximum number of characters to be considered for each keyword?

2. How should we weight considerations of description vs. itemized labeling?
   For example:  four telescopes have Al/Si/C filters. Should they all
   have a keyword like "Al/Si/C", or should they have their filter ID number
   as the keyword, such as "03479 #1", or some hybrid of the two, which would
   make a longer keyword? Part of the problem here is that at the project
   level thus far we make general distinctions between the two filter types
   we have ("AL/SI/C" and "LEX/TI/B") but at some point a user of the
   data will care about the individual calibration curves for each filter.
   The problem is simplified to some extent because each telescope has a
   single filter that will never change.

3. The question about filter names in 2 above applies to detectors. ALEXIS
   detectors have serial numbers such as "AF02", but also have unique
   photocathode materials. Two telescope detectors have MgFl photocathodes,
   and four have NaBr photocathodes. In this case it might be more tractable
   to have hybrid names, i.e. "AF01/MGFL".

4. Should we stick to upper case only?

Jeffrey Bloch					Office:     (505) 665-2568
Astrophysics and Radiation Measurements Group	ALEXIS Soc: (505) 665-5975
Los Alamos National Laboratory			FAX:	    (505) 665-4414
Mail Stop D436					e-mail:	    jbloch@lanl.gov
Los Alamos, NM 87545
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