On Thursday 15 September 2005 12:19 pm, Jesus J. Salgado wrote:
> However, it does not solve the question of what do you need to describe
> a Source (it only leaves a placeholder to add all the properties that
> the source could have, but without trying to define them). I think we
> need something more detailed if we want to use this data model as a base
> to inter-operate in the future.
>
Jesus,
It is true, we have tried to side-step defining what a "source" actually is, and for the near-term, we are happy to start with the Salgado/Osuna/etc model. As you indicate, part of the reason for our side-stepping of this issue was to be able to get to critical structural issues for how to construct a general purpose collection/catalog model. Presumably (at least, we presume :) this model should be reusable to hold more than just sources. I think the debate about sources is whether we prefer to have catalogs hold objects which are oriented towards observational characteristics only, or can we not have theoretical ones (e.g. I may want to construct a catalog of 'galaxies' or 'stars'). I believe we want both, and that we will want to have catalogs which are virtual views of other catalogs (for example, a catalog of galaxies which is cobbled together from several separate source catalogs). Our model is designed with this intention (although still some work to do in this direction, and as always, we are happy to collaborate :) On a related note: what DM -related activity will happen at the IVOA? I haven't seen any information about meetings, etc (perhaps as usual hopelessly out of the loop). I would definitely like to discuss the catalog/collection issues in depth while in Spain! Regards, =b.t.
-- -------------------------------------- | | Dr. Brian Thomas | | Dept of Astronomy | University of Maryland-College Park | | Phone: (301) 405-2312 | Fax: (301) 314-9067 | --------------------------------------Received on 2005-09-15Z17:11:46