Registry providers and SSA enthusiasts,
One of the things we'll talk about this week in Cambridge is support SSA services in the registry. I've been discussing an VOResource extension for SSA with Doug Tody and Markus Dolensky. There is draft schema being considered; however, there are still some issues to be worked out. Nevertheless, there is quite a bit of demand to support current SSA implementations in the registry as soon as possible.
I've set up a twiki page for discussion of this schema.
http://www.ivoa.net/twiki/bin/view/IVOA/SsaResourceSchema
You will find two versions of the schema on that page: one that has all of the elements that are currently desired in the extension, including those that still need further discussion and consideration. The second is a working draft being put forward for immediate support which has the unstable bits removed. If we adopt this version now, it is expected that we would migrate to a final 1.0 version in 3 to 6 months.
One important issue we need to address is how to support the earliest SSA implementations. These were built well before v1.0 of the SSA spec was completed; thus, it is unlikely that they would be compliant at this time. Still, several do exist, and it would be good to recognize these as serving spectra.
VOResource v1.0 allows one to list in one resource description support for different versions of a protocol. For SSA, this means that within the "SimpleSpectralAccess" capability element, multiple interface elements may be listed, each with a different value for its version attribute. (If version is not provided, "1.0" is to be assumed.) I recommend that we encourage the registration of the early SSA services using the "SimpleSpectralAccess" capability but to set the value of the interface element to "proto". That is,
<ri:Resource ...>
...
<capability xsi:type="ssa:SimpleSpectralAccess">
<interface xsi:type="vs:ParamHTTP" version="proto">
<accessURL> ... </accessURL>
</interface>
...
<capability>
...
(If you don't "proto" as a version string, please suggest an alternative, e.g "0.5".)
cheers,
Ray
Received on 2007-09-24Z17:14:52