Data Catalog Side Meeting

The following points were presented and discussed (see File:AQ SOLTA 2011-Data Catalog side meeting.pdf)

Catalog architectures

   * Centralized catalog
   * Distributed catalog
   * Broker catalog

GI-cat, aka EuroGEOSS Discovery Broker: a broker catalog to federate heterogeneous standard services (part of the GEOSS Common Infrastructure)

   * Catalog services (CSW, OpenSearch, ...)
   * Inventory services (THREDDS, WAF, ...)
   * Access services (WCS, WMS, ...)

Broker catalog use cases

  * Addition of new heterogeneous server nodes to the existing capabilities (the MACC WCS was added)
  * Addition of new interfaces to the available services
  * Using GI-cat through the GI-go geobrowser client
  * Using GI-cat through the GI-portal light client

Discovery standards

   * Metadata standards (ISO 19115/ISO 19139)
   * ISO19139 publishing mechanisms (FileSystem, Web Accessible Folder-WAF, Native XML Database-NXD, CSW/ISO)
   * CSW queryables review (ISO properties for discovery)

Access

   * OGC services (WCS, WMS, WFS, SOS)
   * Metadata conventions (CI_OnlineResource) for OWS data access
   * Brokered-access (EuroGEOSS access broker)

Interoperability

   * The Air Quality Community Catalog (metadata and service interfaces, functionalities and role)
   * Test outcomes of GI-cat federating the Air Quality catalog
   * uFind functionalities and features (with a demo of uFind faceted-search); the facets are encoded in metadata keywords, as key-value-pairs with the syntax <facet>:<value>

Other issues

   * AQ metadata for discovery: what are the facets of description for AQ data?
   * AQ data granularity level
   * How can the AQ Community Catalog and GI-cat complement each other effectively?

Discussion summary

Collaboration considered beneficial, for raising awareness of GCI principles among the AQ CoP and, vice versa, for providing AQ user community feedback to the GCI architects. Possible areas of collaborations: semantic discovery, where there already exist an AQ controlled vocabulary (derived from CF conventions); integration and reuse of access facilitators/helpers.

Three possible practical actions:

  * Shepherd the AQCC into EuroGEOSS
  * Harmonize the AQCC and EuroGEOSS (e.g. semantic search)
  * Mutually leverage accessors/adaptors technologies (uFind, GI-cat, GI-axe)