Hi Ben,
Thank you for the useful note.
I think I may need to clarify the situation. The current primary
focus of the CSW/THREDDS gateway that GMU is working on is mainly on
mapping THREDDS catalog metadata to ISO 19115 so that THREDDS
metadata can be made available in an international standard
form. It would be a mistake to divert that project from it's high
priority objectives.
I agree with you: this is a useful objective. Indeed, in the
framework of GALEON phase II, we're interested in providing a
contribution on such topic. In fact, we developed a mapping from
THREDDS data model to an ISO 19115 profile.
Presently, we're testing a similar mapping for CS-W.ebRIM, too.
On the other hand, the question of how to provide inventory catalogs
of "collections" of datasets, and catalogs of those collections --
as THREDDS does -- keeps coming up in many different settings. It
arose in the OGC GALEON interoperability experiment; it came up in
discussions at the 3rd Interoperability Workshop on the Automated
Harvesting of Data and Metadata last week.
In our opinion, this is another important issue. For example, we are
experimenting a Web Service to aggregate distributed THREDDS
catalogs, creating a new virtual catalog, using either a pull or a
push based approach.
---Stefano