[daip] Re: latest FITS format

[Eric Greisen]

Dwarakanath writes:
 >     I need some information regarding FITS format.
 > 
 >     I am aware of the first paper you wrote on FITS format, etc.. However,
 > I would like to know if the current FITS format is still following what
 > you prescribed long time back, or, there have been further changes to it
 > in recent times. If there are changes, do you know of a reference where I
 > can find them.
 > 
 >     The reason for asking is that one of my colleagues is involved in the
 > ASTROSAT project which is an Indian X-ray/optical/UV satellite project. He
 > is planning the data format which can be easily used not only the
 > X-ray/optical/UV community, but also by the radio community. In
 > particular, he wants to make sure that AIPS can read these data formats as
 > well as many other softwares used by the X-ray types. So, he would like to
 > know the 'common minimum' which will facilitate this reading by a large
 > number of users.

The basic FITS has not changed although things have been added along
the way.  In particular, all the early papers were reworded into a
summary document which is now the official standard.  Since then two
papers on coordinates have been accepted:

See


"Definition of the Flexible Image Transport System (FITS)", 2001,
    A&A 376, 359, authors: Hanisch, R. J., Farris, A., Greisen, E. W.,
    Pence, W. D., Schlesinger, B..M., Teuben, P. J., Thompson, R. W.,
    and Warnock, A. III; DOI 10.1051/0004-6361:20010923. 

"Representations of world coordinates in FITS", 2002, A&A, 395, 1061
     (with Mark R. Calabretta).

"Representations of celestial coordinates in FITS", 2002, A&A, 395,
     1077 (with Mark R. Calabretta).

Also the frequency/velocity paper is now under review:

http://www.aoc.nrao.edu/~egreisen/scs.ps
http://www.aoc.nrao.edu/~egreisen/scs.ps.gz
http://www.aoc.nrao.edu/~egreisen/scs.pdf

A good review for amusement would be

"FITS: A Remarkable Achievement in Information Exchange" 2003, in
      Information Handling in Astronomy -- Historical Vistas, Heck, A.
      ed., Kluwer Academic Publishers, Dordrecht, ISBN 1-4040-1178-4,
      Astrophysics and Space Science Libray, 285, 71.

there is also an aips paper in that book.

Note that AIPS itself does not fully supported all of the WCS
conventions in those papers.

ERic Greisen