wcs.ps and scs.ps

[Michael Nolan]

Comments on the wcs paper (1999 April 9 version):

I can reasonably forsee the usefullness of airmass and unit optical depth
as axis dimensions.  

In table 4, adu means A/D converter.  Do you mean converter (as in
physical device), or do you mean DN?  I can see a value in both, and
have a specific need for the former, since we have four parallel IF
chains simultaneously sampled.

You removed the trig functions, which are mainly useful for projections,
and can be handled in paper II, but have other applications, such
as airmass again.  I suspect that if trig functions are needed, they
will simply be used withut difficulty.  The main problem would be how to
represent the inverse trig functions, as it would be better to choose now than
to have all of the possibilities be used later.

-- 
Mike Nolan +1 809 878 2612 ext 280 Fax: +1 809 878 1861 nolan at naic.edu
Arecibo Observatory/Cornell University POBox 995, Arecibo, Puerto Rico 00613