Hi,
this morning I tried to add some comments on
Unified Content Descriptor Controlled Vocabulary RFC page
(http://www.ivoa.net/twiki/bin/viewauth/IVOA/UCDwordsRFC)
I would have add here that pos.precess, pos.eop, pos.eop.nutation really need extensions like phys.polarization and pos.bodyrc.
It seems to me that pos.satellite is not very usefull now that
pos.bodyrc is available. Moreover its equivalent in UCD1,
POS_PLANETARY has very strange usages (see
http://cdsweb.u-strasbg.fr/UCD/cgi-bin/ucd_stats?leaf=POS_PLANETARY&query=Submit)
like, among others, positions of spots on close binary system [in J/A+A/426/1001, Catalog of
contact binary stars (Csizmadia+, 2004) (http://cdsweb.u-strasbg.fr/cgi-bin/VizieR)
(http://cdsweb.u-strasbg.fr/cgi-bin/VizieR-3?-source=34261001&-out=*POS_PLANETARY&-meta.ucd=u)]
Some reflexions about coordinates has to be performed, at least from my point of view. For example, why do we need pos.geocentric and pos.earth etc... but it is perhaps more reasonable to postpone this kind of discussion for a next version of the UCD list.
-- PierreReceived on 2005-09-23Z09:00:04