RFC initiated for Simple Spectral Access protocol

[Anita M. S. Richards]

>> - Section 1.4.1 states "VOTable is preferred if only one format is
>> supported".  I would suggest not preferring one data format over another
>> and leaving it to the data providers to decide. For an "archival" SSA
>> service, which is the more likely type of service to offer only one
>> format, FITS may be a better choice.
>
> This may be a controversial point, but my opinion is that VOTable may
> prove to be a better choice as an interchange format (not necessarily for
> archive storage) for metadata-rich VO spectra, especially since an SSA
> client already has to support VOTable for queries.  Astronomy software is
> already adapting to support VOTable.  I suspect that most new spectral
> services and client software will prefer to support VOTable over FITS.
> I think it is useful to suggest a format for those who will only implement
> one format.  If there is sufficient disagreement we can reconsider the
> point though.
>

I'm afraid that I am with Randy on this.  Yes, VOTable is very convenient 
for some things, but the danger is that if we emphasise it too much for 
spectra, service providers may think that they don't have to support 
anything else.  In fact the majority of spectra at present are probably 
FITS or ascii or goodness knowns what, and in future large data volumes 
may be xml/binary.  Why should we impose a format on spectra when we don;t 
for images? VO tools can handle FITS perfectly well. If I had a large 
collection of FITS spectra with numerous 
extension tables giving the processing history etc., I would not want to 
convert the whole lot to VOTable.  Before someone says that it is 
possible, yes, maybe, but that isn't the point - we should impose the 
minimum requirements on data providers. It is much better to make sure 
that there are tools which can handle at least the few commonest formats 
and convert them if necessary - which may often involve converting a 
sub-set or cutout. More importantly, the metadata must be preserved.  But 
that is not really the province of this discussion.


best wishes

Anita

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dr. Anita M. S. Richards, AstroGrid Astronomer
MERLIN/VLBI National Facility, University of Manchester, 
Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, U.K. 
tel +44 (0)1477 572683 (direct); 571321 (switchboard); 571618 (fax).