Subject: ANNOUNCE: FITS User's Guide version 4.0 Available

From: bschlesinger at nssdca.gsfc.nasa.gov (Barry M. Schlesinger)
Date: 6 May 1997 14:37 EDT

Version 4.0 of the NASA/ADF FITS Support Office User's Guide to the
Flexible Image Transport System (FITS) is now available, in LaTeX,
PostScript, and gzipped PostScript formats. The choice of gzip rather
than .Z is based on two factors: gzip is not a proprietary format, and
the compressed files are smaller.  Printed copies also can be ordered.

There are several changes from version 3.1.

Discussion of the BINTABLE and IMAGE extensions is now part of the
section on FITS fundamentals.  Discussion of the variable length,
multidimensional, and substring array conventions, which are in the
BINTABLE paper but were not formally endorsed by the IAUFWG, remains
in the chapter on Advanced FITS. 

The discussion of physical blocking is now based on the provisions 
endorsed by the IAU FITS Working Group and is included in the section 
on FITS Fundamentals.

The section on World Coordinates has been revised to reflect the
modifications to the Greisen and Calabretta proposal since version 3.1
of the User's Guide was published and some community discussion about
the proposal.  

Descriptions of many proposed conventions have been added to the
Advanced FITS chapter, among them the checksum proposal, the logical
grouping convention, HEASARC keywords, inheritance, and world
coordinates keywords, especially for use in tables. 

The description of FITS resources now emphasizes network and World
Wide Web sources of information. 

Three sample headers have been added to the Appendix: for an ASCII
table containing a catalog and for binary tables containing infrared
and high energy data. 

The User's Guide is available on-line from
ftp://nssdc.gsfc.nasa.gov/pub/fits/users_guide.*, where * is tex for
the LaTeX version, ps for the PostScript version and ps.gz for the
gzipped PostScript version.  The guide.sty style file must be used to
run the LaTeX version.

Printed copies of the User's Guide can be obtained from the
Coordinated Request and User Support Office (CRUSO), open 8:00 A.M. to 
4:30 P. M. U. S. Eastern Time (GMT -4 until October 26, 1997).

(Electronic mail) request at nssdca.gsfc.nasa.gov
(Telephone)       +1-301-286-6695 (has phone mail)

(Postal)
Coordinated Request User Support Office (CRUSO)
Code 633,
National Space Science Data Center
NASA Goddard Space Flight Center
Greenbelt, Maryland 20771, USA

					Barry Schlesinger
                                        FITS Support Office
					GSFC/ADF

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From: dwells at nrao.edu (Don Wells)
Date: 12 May 1997 19:11:20 GMT

Dear friends of FITS,

"BMS" == Barry M Schlesinger <bschlesinger at nssdca.gsfc.nasa.gov> writes:
BMS> Version 4.0 of the NASA/ADF FITS Support Office User's Guide to the
BMS> Flexible Image Transport System (FITS) is now available..
BMS> ftp://nssdc.gsfc.nasa.gov/pub/fits/users_guide.*

The FITS User's Guide is definitely a good thing, and users of the FITS
data format should study it. Newcomers to the world of FITS should pay
special attention to its treatments of FITS evolution, of FITS
work-in-progress and of the differences of FITS style present in
different parts of our community. Its recommended-practice advice should
be considered carefully by creators of astronomy datasystems and
archives.  Barry Schlesinger, the editor of the Guide, has worded his
discussions of these complex--and sometimes controversial--topics with
sensitivity, balance and fairness. I have a high regard for his work.

The FITS User's Guide was proposed at a meeting organized by the NASA
Astrophysics division and held in Annapolis, MD, in 1987. It was to
accompany the formal FITS standard; the idea was that there are many FITS
issues which need to be discussed as guidance for implementors and users,
but which don't fit into the FITS standard document.  The first version
of the Guide (edited by Barry Geldzahler) appeared circa 1989, eight
years ago. The successive releases, at intervals of several years, have
steadily expanded the coverage of the Guide and, with this Version 4.0,
the User's Guide can now claim to discuss--at some level--essentially
every issue which arises in the use of the FITS data format in
astronomy. It is greatly to the credit of the NASA Astrophysics division
that they not only had the vision to start this project, but that they
have also had the patience and faith to continue to operate the FITS
Support Office so that this evolutionary process could proceed year after
year. I hope that we will see, eventually, Version 5.0 of the Guide.  The
sci.astro.fits/fitsbits readership can contribute to this steady revision
and expansion of the FITS User's Guide by sending corrections,
suggestions and proposed new text to Barry Schlesinger at the Email
address given above.

-Don Wells (Chair, IAU FITS Working Group)
--
  Donald C. Wells         Associate Scientist         dwells at nrao.edu
                    http://fits.cv.nrao.edu/~dwells
  National Radio Astronomy Observatory                +1-804-296-0277
  520 Edgemont Road,   Charlottesville, Virginia       22903-2475 USA