[Radioig] ObsCore Radio Extension

[BONNAREL FRANCOIS]

Dear all,

There is a new version of the ObsCore extension for radio data, with a 
"Proposed Recommendation" status

There are a lot of changes with respect to the previous "Working draft" 
published one year ago.

Among those changes :

        - a long list of science cases in the Appendix

        - f_min and f_max have been removed: but science cases with 
frequencies are still there and various solutions to constrain frequency 
limits are given

        - the extension attributes are isolated in a different table 
than the obscore one. A standardID is proposed for this table and will 
appear in the registry table_utype attribute.Beside this a standardID to 
set on the ivoa schema if it contains ObsCore AND the extension is also 
defined.

Last but not least  : JIVE implemented the service in 
http://evn-vo.jive.eu/tap/ (thanks to Mark K, our new RIG chair). Look 
at radio_obs and evn.main tables.

Cheers

François