[wfc] Next: Checksum proposal

[Arnold Rots]

Dear WFC,

Not losing any momentum in clearing old business, attached is a letter
from Bill Pence on the Checksum proposal that is still pending in this
committee.  It was submitted in April and after discussion a revised
version was produced in May.

At this point I would like to ask whether anyone has additional
comments on or objections to the new version of this proposal.
If such is the case, we will need more discussion; if not, I would
like to move to a vote on the proposal.

Please respond by Friday, November 15, 2002.

Thank you,

  - Arnold

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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head-cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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We (Rob Seaman, Arnold Rots, and I) have reached a consensus on a new
version of the checksum keyword proposal which we are now resubmitting to
the WGAS FITS Committee for their consideration.  This incorporates the
changes that I had proposed in my previous message (copied below).  It is
available from the same web as before:

http://heasarc.gsfc.nasa.gov/docs/heasarc/fits/checksum.html

This 23 May 2002 version of the proposal now contains virtually all the
discussion from the 1995 version of the proposal (but is still only 1/2 as
long). This makes it a more complete and self-contained document as was
requested in particular by Don and Eric.

The proposal is now organized into 2 main sections, much like the Y2000 FITS
agreement: The main body of the proposal contains a concise definition of
the DATASUM and CHECKSUM keywords.  We envision that this section, if
approved, will be added to section 5.4 of the FITS Standard.  This is
followed by an appendix  which presumably would be added as an appendix to
the Standard.

regards,
Bill Pence

William Pence wrote on 02 May 2002:
>
> I'd like to offer a suggestion to modify the organization of the checksum
> proposal to meet the requests by Don and Eric to make it more self contained
> and contain more background or overview information:  The current proposal
> could be reorganized to contain a short main section that just defines the
> DATASUM and CHECKSUM keywords, followed by an appendix that contains
> everything else, including:
>
>  - a slightly longer introductory section, as in the 1995 paper
>  - the recommended implementations from the current proposal
>  - the coding examples from the current proposal
>  - the "Alternate Checksum Algorithms" section from the 1995 paper
>  - and perhaps a 'recommended usage' section, if anyone has anything useful
>    to say
>
> The intention then would be that the short main body of the proposal would
> be integrated into the FITS Standard proper, and the appendix of the
> proposal would be added as an appendix to the FITS Standard. (Whether this
> appendix is actually voted on and approved by the WFC, or whether is is
> prefaced with the statement "This Appendix is not part of the NOST FITS
> Standard, but is included as a guide to recommended practices" remains an
> open question).
>
> More specifically, the main body of this revised proposal would just contain
> what is in sections 1, 2, and 3.0 (and not 3.1 or 3.2) of the current
> proposal.  How this is actually integrated into the FITS Standard should be
> left to an editorial panel to decide, but a reasonable suggestion would be
> to insert this as a new section 5.4.2.7, "Checksum Keywords".
>
> The remaining material would be added as an appendix to the Standard, where
> it is more permissible to have more narrative discussions.
>
> If this seems reasonable to everyone, I can prepare a new draft in the next
> day or 2.
> 
> -- 
> ____________________________________________________________________
> Dr. William Pence                          pence at tetra.gsfc.nasa.gov
> NASA/GSFC Code 662         HEASARC         +1-301-286-4599 (voice)     
> Greenbelt MD 20771                         +1-301-286-1684 (fax)
>