Session 3A: Catalog Services and Metadata Models Doug Nebert, Joshua Lieberman, Jolyon Martin USGS, OGC, ESA

Agenda Definitions: catalog, registry, repository, archive, clearinghouse, portal Catalog roles and goals Catalog use cases Catalog service interfaces Catalog interoperability Metadata, metamodels, registry metadata Metadata standards, profiles, packages Significant profiles

Definitions Catalog Registry Repository Archive Clearinghouse Portal Service / arrangement for discovering resources through metadata Registry Service / arrangement for managing catalogs and registers through metadata about metadata Repository Persistence / storage function particularly for metadata resources (access by ID) Archive Function/service/capability for managing the persistence of data resources (lifecycle, lineage, provenance) Clearinghouse Broker for access to capabilities, particularly metadata resources Portal User (Web) application which supports multiple functions, multiple audiences and/or multiple sources / modes of access to capabilities. Not a service per se but may be implemented by a generator service

“Catalog” roles Authority Trader Authority Trader Broker Provider Standards, vocabularies Trader Publish, find, match Broker Access, aggregation, translation Authority Trader Provider Consumer Broker

Catalog Goals GEOSS-wide discovery Service deployment and registration Discovery broker across protocols and Standard discovery interfaces (small number of) Service deployment and registration Registration of catalog services with extent and theme ?

Publish-Find-(Bind) Use Case

Distributed Search Use Case

Discovery and Binding Issues How much information is enough, how much is too much for a catalog? Metalevels Community Capability Service Collection Item Item component Process model / capabilities Currency Distribute versus harvest Status metadata versus status operation

Catalog service interfaces OGC Catalog - CS/W Z39.50 ISO 23950 UDDI ebRS OAI WFS? OPeNDAP Query Echo client partner API’s

Catalog interoperability levels Service interface / protocol Messages, interaction styles Metamodel Text Record Graph Metadata model Query language Format / encoding Registry metadata elements and content Status, currency, provenance Relationships Classifiers Statistics Trust and authority Intention and application

Metadata, metamodels, registry metadata “Data about data” Application-dependent (“One Man’s metadata…”) Metamodel “Language for describing metadata” Registry metadata “Metadata about metadata” e.g. Resource identifiers, classifications

Metadata standards, profiles, packages ISO 19115 / 19115 part 2 / 19139 FGDC Content Standard FGDC Biological Data Profile Darwin Core DDMS ABCD EO-HMA Dublin Core Services OWS ISO 19119 WSDL WSRF OWL-S SAWSDL

CS/W Base Profile Discovery manager interface CSWRecord metamodel Consists mainly Dublin Core properties OGC Core queryables Brief, summary, full result sets Special attributes: [WGS84]BoundingBox AnyText

CS/W ebRIM (Meta)profile and Basic Package ebRIM provides specialized record types which represent registry metadata or a metamodel for describing metadata. Basic package is a set of ebRIM records to support OWS metadata Extension packages (e.g. SWE, EO, ISO) add ebRIM records to support other resource domains.

Catalog 101 ebRIM Nomenclature Implementor’s view CSW with ebRIM management model Definition of domain resource types Resource management tools ebRIM Nomenclature Your (Meta) resources Extrinsic Objects Your Identifiers Resource IDs Queryables Slots Relationships Associations Categories Classifications

NASA Echo Registry / Broker Service and Data Registry SOAP API’s for discovery, as well as OPenDAP query and UDDI Also provides brokered data access / ordering Partner API’s are open, but generally not (OGC, ISO) standard Data Registry CollectionsGranules Browse Images Extended Services Registry Data Partner APIs Client ECS-DAACs Heritage DAACs Other Data Partners Modeling, Applications, Decision Support Systems General-Purpose GUIs Tailored Graphical User Interfaces Client Partners Data Partners

Discussion Lifecycle and currency - seems to be another form of registry metadata. Internal timestamps may be hard to interpret in terms of actual data currency. For update currency, a “push” in the form of GeoRSS item publication may be useful. Should there be one or more “GEOSS Recordtypes” which are more precise extensions of CSW_Record but interpretable across community catalogs? Over next three months, does the clearinghouse need to customize queries to each community catalog, e.g. for time? This is obviously not scalable over the long term. Clearinghouse workplan item: register catalogs and start evaluating how likely scenario queries need to be constructed against those catalogs - are there query “families” or (worst case) is there a unique query / protocol for each catalog? BODC Vocabulary Service (SKOS interface) might be useful in query expansion for some topics. Official gazetteer? E.g. GNS, GNIS, Geonames.org, Alexandria?

Significant Queryables and Returnables Time period of data validity Time period of collection Resource type Full text Geographic Extent Topic categories / ISO terms Title Creator Organization Language Scale / resolution Metalevel Classification Processed state Returnables Identifier Resource locator Quality Description Abstract Copyright / Use constraints Source Last update