1. Session 2: Metadata and Catalogues
Metadata Standards
The Scope of Metadata
Registries, Catalogues, Repositories
Registry Standards

2. What is Metadata? The famous definition... Descriptive information.
Not just about data, also about services, or anything else.

3. Metadata Standards: Dublin Core
15 core elements of metadata
contributor, coverage, creator, date, description, format, identifier, language, publisher, relation, rights, source, subject, title, type
Used in many other standards

4. Metadata Standards: ISO 19115
Most well-known standard for geospatial metadata – describes data.
Quite large and complex.
People define profiles for particular purposes, that are more manageable:
ANZLIC profile.
INSPIRE profile.

7. Metadata Standards: ISO 19119
A framework for developers to create interoperable software.
Architecture patterns for service interfaces.
Includes service metadata.
Geographic services taxonomy.
How to create a service specification.

9. Geographic Services Taxonomy
Defines a taxonomy of services and their functionality.
6 broad categories, each with a number of service types. e.g. Geographic processing services:
spatial, thematic, temporal, metadata.
Spatial includes coordinate transformation, image conversion, tiling, feature manipulation.

11. Also Geoprocessing Architecture
Patterns for service chaining:
Opaque (aggregate);
Transparent – user defined;
Translucent – workflow managed.
Various other aspects of service chaining specified and standardised.

12. What is metadata used for?
Discovery of data and resources.
Management of resources in a Spatial Data Infrastructure (SDI).
Geoprocessing/service chaining.

13. Discussion Current use of metadata? Types of metadata?
What is it used for?

14. Possible range of metadata for an SDI or KI
Metadata about data.
Metadata about services.
Other things:
Schemas;
Annotations;
SLDs;
Ontologies...

15. What is a catalogue?
A structured collection of descriptive data about data, services and related objects to support a spatial data infrastructure, knowledge infrastructure or similar.
Catalogue = Registry.
Repository also contains actual content (documents, etc).

16. Catalogue Interfaces and Services
We access the catalogue through a catalogue service that conforms to a specified interface.
This provides interoperability.
A key part of an SDI/KI, allowing access to distributed resources.

17. Distributed Catalogues
Often multiple catalogues:
different types of content;
different themes;
served by different organisations.
May need a broker/mediator (e.g. EuroGEOSS, COMPASS).

18. OGC Catalogue Services Specification
Abstract specification:
Abstract methods for interface
Queryable and returnable metadata
Bindings to different protocols
CSW: HTTP binding
Abstract, so need application profiles.

19. Methods Publish metadata – add, edit, delete content in the registry.
Discover metadata – search for features represented in the registry;
by ID or attributes;
FILTER language, and others
Harvest

20. ISO 19115/19119 Application Profile for CSW
Information model
from ISO and
Mapping to/from abstract metadata properties.
Sets of properties (brief, full, summary)
Details of abstract methods (payload etc).
Can be extended with MD_ExtensionInformation

21. ebRIM Application Profile for CSW (WRS)
Information model based on ebRIM.
Equivalent content.
ebRIM comprehensive information model:
Services, Classifications, Users, Organisations, Events, Access Control.
extrinsicObject can be used to extend.
New version in development (RegRep 4).

23. OWL Application Profile for CSW
Information model based on RDF/OWL.
Equivalent content.
Can be used for any RDF or OWL content (more later).
Creates a semantic registry.

24. Other Useful Documents
Extension packages:
Show how you would use an application profile for a particular purpose:
Feature Type Catalogue (ebRIM)
Earth Observation Products (ebRIM)
Other documents:
OWS4 Guidelines for mapping from domain model to ebRIM

25. Summary
Metadata describes the services, data, schemas, other supporting information for an SDI.
Registries store all this information to support discovery and management.
e.g. MOTIIVE.