Error column in VOResource

[Patricio F. Ortiz]

On Tue, 18 May 2004, Clive Page wrote:
> On Tue, 18 May 2004, Roy Williams wrote:
>
> > But what happens when there is an error ellipse, RA, Dec, and the three
> > components RA.RA and Dec.Dec and RA.Dec of the covariance.
>
> How often does this happen Roy?  I don't know of any standard catalogues
> where there's a covariance, and I don't think we've got a UCD to handle
> this case either, have we?  If it's a very rare case, maybe we can agree
> to ignore it, whereas quite a good proportion of tables have explicit and
> separate RA and DEC errors, and all the rest have them implicit.

Hipparcos and Tycho, if I'm not wrong, UCD1 did encompass these concepts
(but they were used once or twice :-) :-)

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
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