> > Okay, I'd like to bring up my current pet peeve about the NVO cone search
> > standard (ie http://www.us-vo.org/metadata/conesearch/), which is that it
> > doesn't include either equinox or epoch.
> >
> > Both of these are vital for people wanting to do real science with the
> > catalogues. If the adopted standard doesn't include these things, people
> > doing galactic work won't use the interface because the retrieved
> > catalogues aren't going to be valid. We can _not_ assume J2000 for both
> > equinox and epoch, it just won't work!
>
> Errm, as I understand it, the business of converting from one equinox to
> another is straightforward and well understood. So can we assume that the
> cgi *query* is always J2000, and the catalogue database behind it converts to
> that using standard libraries?
Err, not exactly...
> As for the epoch, as most databases provide the viewing epoch for each
> object, that should provide enough information?
Depends, does your DB contain proper motion information for instance?
> It may create more work at the client end, but it makes it much easier
> to publish databases, which encourages people to do so.
I might want to let Tim Naylor comment on this perhaps? He's currently doing interviews but I think he might want to chip in here, I'll catch him later today and ask him to throw a mail to the list about this one...
Its an important point, and something that people are currently ignoring.
> Agree lots. Publishing data easily, using readily available (whether SOAP
> and/or cgi-like querying and/or other) techniques, gives us a framework for
> building all kinds of industry-wide tools, including but not limited to grids.
Agree lots...
> However I would like to keep an eye on the inherant limitations of using
> http: it's a simple request/response protocol, with no concept of session
> state. This makes it simple to use for small queries (which may be 90%? 99%?
> of likely queries?) but really awkward to use for large queries. State can
> be added, yes, but it's a layer of extra stuff to add on *top* of http -
> seems a waste given there's state in TCP/IP connections (*under* http)!
This is a valid point, but I'm not convinced that OGSA/OGSI is the answer we're looking for...
Cheers,
Al.
--
Dr. A. Allan, School of Physics, University of Exeter
Received on 2003-10-06Z08:43:18