Comments on SSAP V0.95, UCDs

[Gretchen Greene]

Doug,

Let me get this clear,  to specify ra, dec you are seriously considering
something to level 4 hierarchy?  

-Gretchen

-----Original Message-----
From: owner-dal at eso.org [mailto:owner-dal at eso.org] On Behalf Of Doug
Tody
Sent: Tuesday, June 27, 2006 2:01 PM
To: Randall Thompson
Cc: dal at ivoa.net; Inga Kamp; Myron Smith
Subject: Re: Comments on SSAP V0.95, UCDs


On Tue, 27 Jun 2006, Randall Thompson wrote:

>   What I was hoping for was something equivalent to the
> UCDs POS_EQ_RA_MAIN and POS_EQ_DEC_MAIN defining
> the "primary" coordinates for a given observation, that would be 
> included in the query results returned for any protocol. Will there be

> a single equivalent UTYPE I can use instead?
>   Randy

Yes - Assuming we still try to use characterization for this, probably
it will be provided by something like
SpatialAxis.Coverage.Location.whatever.
If that proves too complex for something this fundamental (we still
don't know how to specify a coordinate at this level), we will define a
special field for this purpose with a fixed coordinate system reference
frame, as in the past.  Whatever is decided, it will be a well defined
interface element with a fixed UTYPE so that you can just look up the
position by its UTYPE string.

 	- Doug