1. Session 4A: Federated Catalogs and GEOSS Clearinghouse
Joshua Lieberman
Open Geospatial Consortium

2. Agenda What is federation? Integration? Centralization?
Styles of federation
Proper domains, communities, and governance
Broker roles in service oriented architectures
Distributed query protocols and strategies
Metadata interoperability, semantics, and trust
Role of the GEOSS Clearinghouse in the AI Pilot.
What Clearinghouse offers are being made?

3. What is federation? Federation in governance (Wikipedia)
A federation (Latin: foedus, covenant) is a union comprising a number of partially self-governing states or regions united by a central ("federal") government. In a federation, the self-governing status of the component states is typically constitutionally entrenched and may not be altered by a unilateral decision of the central government.
Federation in identity (Wikipedia)
In information technology, federated identity has two general meanings:
The virtual reunion, or assembled identity, of a person's user information (or principal), stored across multiple distinct identity management systems. Data is joined together by use of the common token, usually the user name.
The process of a user's authentication across multiple IT systems or even organizations.
Federation in information systems (
“Constructed as an integrating layer over existing legacy applications and databases. They can be broadly classified in three dimensions: the degree of autonomy they allow in integrated components, the degree of heterogeneity between components they can cope with, and whether or not they support distribution.”
Integration
Subsumption of individuals into a whole
Centralization
Collection of distributed information into a single location

4. Styles of federation
Top-down
Bottom-up
Peer-to-peer
Third-party

5. Topic: Proper domains, communities, and governance
Knowledge domains
Information communities
Governance

6. Broker roles in service oriented architectures
Protocol access
Information transformation
Knowledge mediation
Business overlay
Trust establishment

7. Distributed query protocols and strategies
Distributed query versus harvesting
Stored / cached queries
Update channels and messages
Query differentiation
Response translation
Aggregation
Query status messaging and user-client interactions
Completeness and quality

8. GEOSS Clearinghouse Engineering
Not an authority
Not a repository
Needs an operational entity in the Pilot context
Relies on community catalogs
Maintains registry metadata for operation (e.g. QoS)

9. Role of the GEOSS Clearinghouse in the AI Pilot
Capability
Scenarios
Interaction with GEO Portal
Digital divide
Lifetime

10. Discussion - Clearinghouse Offers
Offers (potential or needing clarification):
FAO GeoNetwork (community catalog and software offer)
Geodata.gov (community catalog offer)
JRC INSPIRE Geoportal Catalog (community catalog)
ESRI Geoportal (catalog software offer)
ESA Eoportal (EOLI interface community catalog)
Compusult Service Manager (catalog software offer)
Categories
Thematic catalogs which “could” harvest more content
“Empty” catalogs which could be devoted to GEOSS resources for the pilot

11. Discussion
“Political interoperability” - possible complementary efforts
GEO technical capacity
UNSDI mandatory governance
Implementation strategies
Stand up an existing empty catalog as an initial Clearinghouse to start gathering experience and support portal development (mainly harvesting)
Should we support multiple initial Clearinghouses?
ESRI
Compusult
GeoNetwork
Finalize requirements for Clearinghouse software development (supporting policies of both distributed query and harvest)
Leaves harvesting heterogeneity to deal with between the multiple instances.
Examine effect of different harvesting strategies to decide Clearinghouse strategy.
Work towards “groups” or key community catalog targets and eventually conformance recommendations for community catalogs

12. Community Catalogs (of Distinction)
Geodata.gov
ESA EoCatalog (HMA)
INSPIRE Catalog
FAO GeoNetwork
ESG - Echo ?
GCMD ?
GBIF ?

13. Workplan Questions and Items
How long should initial Clearinghouse instances commit to operation? What level of support / service?
What community catalog commitments are to be requested, particularly from key instances? Quality of Service, support contact, ..
What is the duration of the workplan?
Update requirements in CFP based on feasibility and scenario needs.
Evaluation, analytics
Review / update distinctions and boundary between Clearinghouse and GEO Portal. E.g. proper metadata domains.
Review / update sequence diagrams.