[fitsbits] FITS reference

[William Pence]

I plan to follow Malcolm's suggestion for the COMMENT strings that
CFITSIO writes in the primary header of every new FITS file.  The comment 
strings currently written by CFITSIO look like this:

COMMENT   FITS (Flexible Image Transport System) format defined in Astronomy
and
COMMENT   Astrophysics Supplement Series v44/p363, v44/p371, v73/p359,
v73/p365.
COMMENT   Contact the NASA Science Office of Standards and Technology for
the
COMMENT   FITS Definition document #100 and other FITS information.

and the new comment strings will look like this:

COMMENT   FITS (Flexible Image Transport System) format is defined in
'Astronomy
COMMENT   and Astrophysics', volume 376, page 359; bibcode
2001A&A...376..359H.

These will be placed as near as possible to the beginning of the primary
array
header;  they will not be written into any extension headers. (This was the 
consensus back in Aug-Sept 1993 when this issue was first discussed here).

At the risk of stating the obvious, any FITS files created with the next
release of CFITSIO will not be identical to the same files created with the
previous releases of CFITSIO, because the number and content of these
COMMENT keywords will be different.  This could be an issue for
projects that do software regression tests by checking to see if the newly
created FITS files are identical to a reference set of files created with
the previous version of the software.

-Bill Pence
-- 
____________________________________________________________________
Dr. William Pence                          pence at tetra.gsfc.nasa.gov
NASA/GSFC Code 662         HEASARC         +1-301-286-4599 (voice)     
Greenbelt MD 20771                         +1-301-286-1684 (fax)