For the demonstration project OCA and MIDA atlases will build a Catalogue Services for the Web (CSW), where the Web Map Services (WMS) will be registered. The portal will have semantic mediation capabilities as describe below.
Implementation of a OGC CSW 2.0.1 (Catalogue Services for the Web)

Technology to be used Geonetwork
CSW /ISO 19139 2.0.1 is composed of the following interfaces (examples are provided as a link)

• GetCapabilities

  Describes: general information (title, abstract, keywords, service provider information), operations (name, protocol, parameters), filter capabilities (spatial). Main operations are: GetCapabilities, DescribeRecord, GetRecords, GetRecordById.

• DescribeRecord
  Returns the schema

• GetRecordById

  Returns metadata in ISO 19139

• GetRecords
  Returns metadata in ISO 19139

Semantic mediation process Portal - Data Providers interaction

Process:

1. Data Providers publish a CSW which describes WMS. For each WMS description their is a topic associated with it Need example and XPATH of where to put the topic?
2. Portal presents english labels for the upper ontology (super terms)
3. Users selects one
4. Portal finds narrower terms (subclass of the selected terms), via a SPARQL query to an ontology repository.
5. Portal previously invoked CSW services, extracted the application ontology terms and the relation to the endpoint services (e.g. WMS) and store this in a service-ontology. Need to know the XPATH of getting the WMS and the topics for associated with each WMS?
6. For each narrower term from item 3, portal finds the associated services in the service-ontology
7. Portal invokes each service found and gathers information (end point and description) Need to know the how to construct the URL to GETRecords and XPATH ?
8. Portal presents links to the map and a brief description