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

2. 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

3. 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

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

5. 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 ?

6. Publish-Find-(Bind) Use Case

7. Distributed Search Use Case

8. 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

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

10. 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

11. 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

12. Metadata standards, profiles, packages
ISO / 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

13. 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

14. 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.

15. 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

16. 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

17. 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?

18. 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
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