Subject: WCS draft paper for comments

From: egreisen at primate.CV.NRAO.EDU (Eric Greisen)
Date: Thu, 4 Feb 93 17:36:30 EST

I have been working on coordinate representation in FITS and have,
with Mark Calabretta's great help, prepared a draft proposal.  It
is just that - a draft.  I'm sure I will find things I forgot to
put in as will Mark and I am sure that many of you will have
suggestions as well.  I hope that you will keep them temperate and
constructive.  Since I am about burned out on this for a few days
or more, I have decided to release the drafts for comment.  They
are on the computer called fits in the anonymous ftp area with the
following README file.  I look forward to hearing from you - I think.

                                        Eric

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          Representation of Coordinates in FITS

This anonymous ftp area (fits.cv.nrao.edu [192.33.115.8] :
/FITS/Documents/FITS_wcs) has been set aside for documents concerning
the representation of the coordinates of the pixels in FITS images.
My two early AIPS Memos (27 and 46) have been recovered and recast
into modern LaTeX (from TeX -1 or so).  In so doing, we simply
digitized the old figures with a scanner and inserted them in the
documents.  They are called aips27.ps.Z and aips46.ps.Z and are of
a reasonable size when compressed.  They become over 2 and 1.4 Megabytes,
resp., when uncompressed!  Try "zcat <file> | lpr -Pxxx" to avoid on-disk
decompression; else "lpr -s -Pxxx <file>" to avoid complaints about
too-large files.

The working document for a FITS paper authored by myself and Mark
Calabretta (and presumably others to be named later for political
or real reasons) is called wcs.ps.xxxx.Z.  The xxxx is "none",
"some", "most", and "all" depending on the figures actually
represented in the paper (rather than shown as blank \vskip's).
The figures are drawn with postscript programs which have all been
verified with our printers and ghostview.  However, we have found
several models of "postscript" printer which simply fail on the
documents and others which work, but are exceedingly slow.  Hence,
the quicker-to-print versions.

If you find that you cannot read the papers via ftp, or cannot get
them to print, you may obtain paper copies of all 3 are by contacting

       Ernest Allen
       National Radio Astronomy Observatory
       520 Edgemont Road
       Charlottesville, VA 22903-2475

       e-mail: eallen at nrao.edu
       phone: 804-296-0209
       fax:   804-296-0328

Please let us know your comments (well-considered and temperate only), so
that we may develop a consensus which will allow the final wcs.ps to
become a new FITS standard.

                                     Thanks,

                                     Eric W. Greisen,
                                     Scientist.
                                     National Radio Astronomy Observatory
                                     egreisen at nrao.edu
                                     804-296-0348