Re: Comments on V1.1 - Future of VOTable (flame bait sigh)

From: Clive Page <cgp-at-star.le.ac.uk>
Date: Wed, 14 Apr 2004 10:19:43 +0100 (BST)


On Thu, 8 Apr 2004, Martin Hill wrote:

> However let us please please not make it the long term defacto standard for
> astronomical data!

I think that whether it becomes a de facto standard or not depends not on us but on the whole community. The FITS standard started out as purely a tranport format, but gradually became a viable storage and processing format as tools were developed, especially the FTOOLS suite from GSFC. If some group were to rewrite (sorry, out-of-date buzzword, re-factor) the FTOOLS programs to handle VOTable as well, maybe VOTable would become as wide spread.

> have at the end of it is a verbose, limited structure, VO-specific data
> metaformat - a bit like FITS but less well known, with less tools and
> libraries, and requiring more processor time, bandwidth and disk storage.

Not necessarily: you may be forgetting that one of the three valid VOTable formats is as a wrapper around a FITS file. This makes it reasonably efficient.

> The big advantage of VOTable over FITS is a well-defined metadata area and
> human-readability; the former necessary for the VO, the latter useful for
> debugging but let's face it, is mostly useful because of the lack of VOTable
> tools.

I disagree with that. I think FITS metadata are just about as well-defined as those of VOTable, and if anything the headers of a FITS file are more legible (though that depends a bit on which tool you use to view them). Having said that, I feel that FITS metadata are still sadly lacking (and thus VOTable metadata are in an even more primitive state). The FITS Standard only defines a smallish number of headers to describe the data (as opposed to the data structure), and as a result some FITS-using communities have defined their own ad-hoc standards. The high-energy astronomy community, for example, has developed some describled here:
http://legacy.gsfc.nasa.gov/docs/heasarc/ofwg/ofwg_recomm.html

The VOTable standard will not be anything like complete, in my opinion, unless it takes on board the need to define standard ways of defining all sorts of metadata like these. Maybe the DM group needs to be involved?

Fortunately VOTable, like FITS, is an extensible system, so these can come along gradually. But the sooner we start the better.

-- 
Clive Page
Dept of Physics & Astronomy,
University of Leicester,
Leicester, LE1 7RH,  U.K.
Received on 2004-04-14Z11:20:16