[iaufwg] Final FITS review comments

[William Pence]

Dear IAU FWG members,

Regarding the first 15 of the 16 suggestions I made last week on how to 
respond to the final set of review comment on the new draft FITS 
Standard, Arnold Rots corrected my error in the formula for the 
'optical' radial velocity, and also pointed out the distinction between 
2.1*10^9 bytes and 2.1 GB.  With these corrections, here then is the 
current complete list of 4 final changes to the draft 3.0 FITS Standard:

1.  In section 1.1, change "lead" to "led".

2.  In section 3.1, change "(approximately 2.1 GB)" to "(approximately 
2.1*10^9 bytes)".

3.  Add the following footnote to table 8.5:
- By convention, the "radio" velocity is given by $c(\nu_0 - \nu)/\nu_0$
and the "optical" velocity is given by
$c(\lambda - \lambda_0)/\lambda_0$.

4. In Appendix F, add the trailing space in 'FOREIGN '.


If anyone has any further comments or suggestions regarding these first 
15 issues please let me know by the end of this week.


Regarding the last issue (number 16), having to do with documenting 
changes or inconsistencies between different versions of the FITS 
Standard document, there was (again) a divergence of opinion on how to 
proceed.  I think, however, 2 common themes are emerging that point to a 
way to resolve this issue.  The 2 themes are:

1.  It is important and useful to collect and document the changes that 
have occurred in the definition of the FITS format over the years.   We 
should preserve what information already exists, and as time and 
resources permit, strive to make sure this information is complete and 
is presented in the most useful format for FITS users.  As a starting 
point in this effort, we already have available the following documents:
   a) the "Differences from IAU-endorsed Publications" appendix that
      was in versions 1 and 2 of the FITS Standard
   b) the written summaries of significant changes that were produced
      during the public review process of the 2.0 version of the
      Standard in circa 1998, and the 3.0 version in 2008.
As a first step, I volunteer to put these documents in a prominent 
location on the FITS Support Office web site to ensure that they remain 
readily available.

2.  The second theme that several people have echoed is that this effort 
to document past changes should not hold up the vote on the draft 3.0 
version of the Standard, as it now stands.  This new draft 3.0 version 
has many new features (e.g., documenting recommended units strings, and 
defining the WCS conventions, to name just a couple) that we should make 
publicly available as soon as possible.

Accordingly, in an effort to move forward, I put the following 2 
specific motions up for consideration:

Motion 1.  Call for 3-4 volunteers to serve on a committee to a) review 
the past changes to FITS, and b) make a recommendation back to the IAU 
FWG on what specific changes (if any) should be documented within the 
FITS Standard, and how it should be done (e.g., as footnotes, or as an 
appendix, or some other means).  This committee would be asked to report 
back its findings within some reasonable time period, say perhaps 6 months.

Motion 2.  Proceed as soon as possible with the final IAU FWG vote on 
whether to approve the current 3.0 draft, (with the 4 minor changes 
noted above) as the new official FITS Standard document.

Does anyone wish to make any comments on or amendments to either of 
these motions?

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