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From: bschlesinger@nssdca.gsfc.nasa.gov (Barry Schlesinger)
Newsgroups: comp.graphics,sci.astro,sci.space
Subject: Fundamental FITS Information
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Date: 7 Nov 90 16:33:41 GMT
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Fundamental FITS information can be obtained primarily from three 
papers:

Wells, Greisen, and Harten, 1981, "FITS: a flexible image transport 
system", Astronomy and  Astrophysics Supplements, v. 44, p. 363.

Grosbol, et al., 1988, "Generalized extensions and blocking factors 
for FITS", Astron. Astrophys. Suppl., 88, 359.

Harten, et al., 1988, "The FITS tables extension", Astron. Astrophys. 
Suppl., 88, 365.

These titles show that FITS is capable of transforming a far wider 
range of information than simply digital images.

An additional paper immediately following the first one cited above 
discusses "groups" format.  In practice, this format is used only to 
transfer and store radio interferometry results.  It is not widely 
used or understood elsewhere.

In original FITS, as discussed in the first paper, the data matrix 
could contain only integers.  By international agreement, it now may
contain IEEE-754 single and double precision floating point.  
A data matrix consisting of floating point numbers is signalled by
negative values of the BITPIX keyword (-32 for single and -64 for
double precision). 

The FITS Handbook is not yet available; the first sections are 
expected to be available later this year.

We have not yet collected contributed software.  Probably, this office 
will have available information on availability of software that the 
originators are willing to make available before software is available 
directly from this office.

					Barry Schlesinger
					NSDSSO FITS Support Office