Comments on SSAP V0.95, UCDs

[Doug Tody]

Hi Randy -

The purpose of UTYPE is to identify interface elements; they are intended
to be used for this purpose in SSA, and the SSA protocol will specify all
the UTYPEs independently of the underlying data model.  UTYPE replaces
the "VOX" UCDs used in SIAP, and the next SIAP will use UTYPE as well.
UCDs can also be specified, but different interface elements may have the
same UCD so these cannot be used to identify interface elements.

	- Doug


On Tue, 27 Jun 2006, Randall Thompson wrote:

> Hi Doug,
>     Thanks for the reply. I hope to discuss
> the issues further with Bob and the MAST staff
> when everyone is back from travel.
>     One issue I forgot to ask about was the status
> of UCDs in the SSAP. Currently our service-handling
> software relies on UCDs to identify the main RA and Dec
> values, data links, etc. and works with both cone searches
> and SIAP requests. I was hoping the same UCDs would
> be required for the SSAP so we could use the same code for
> all three protocols. Since UTYPES can vary with the
> data models, they would not be as useful for this purpose.
> Is it possible that we can continue the requirement of
> specifying UCDs for at least the more important SSAP
> parameters?
>
> Randy
>