On Tue, 21 Oct 2003, Anita Richards wrote:
> Please can I clarify a possible application, which may initially be done
> in an ad-hoc way until data models are fully harnessed:
>
> Supposing we are harvesting a catalogue which consists of radio flux
> densities measured at 22 GHz. This is stated in the Abstract or ReadMe or
> maybe even the title, but there is no table in the data saying 'observing
> frequency'. As I understand it, we could add a virtual column
> em.radio.12-25GHz, in which all the entries are the same. Can this be
> done as a default, so that the data are recognised at their proper
> frequency?
Anita,
the way UCD1 would handle this is that the UCD associated to the flux will reflect the region of the radio spectrum, eg, PHOT_FLUX_RADIO_11-25GHz, therefore, your catalogue will be discovered by the presence of that UCD without having to add a virtual column describing the observed frequency range. This case was very common, and not only in radio. There are hundreds of columns with "magnitude" as explanation, and you find the waveband in either the readme or the table title. UCDs are supposed to reflect the quantity as well as possible, that's why even with UCD1 one can launch discovery queries of this type and discover catalogues which have no indication of that part of their content in other pieces of meta-data information.
Cheers,
Patricio
--- Patricio F. Ortiz pfo-at-star.le.ac.uk AstroGrid project Department of Physics and Astronomy University of Leicester Tel: +44 (0)116 252 2015 LE1 7RH, UKReceived on 2003-10-21Z12:01:25