CNES implementation of the ISO standard An extension of the current CNES implementation of the ISO metadata standard

Paul Kopp – WGISS 21 2 CNES Metadata Clearinghouse Goals Repository of metadata stored under various formats Metadata may be retrieved by the user through a web browser metadata are information relevant to data (ISO metadata), or relevant to services (ISO service metadata) metadata may be retrieved from several interconnected similar clearinghouses Central services provided by the metadata clearinghouse metadata ingestion and storage metadata retrieval service activation Ancillary services provided by the metadata clearinghouse clearinghouse administration metadata management (including service metadata management)

Paul Kopp – WGISS 21 3 How does it work? ISO & ISO metadata are given as XML documents Document Type Definition (DTD) derived from the metadata UML models no XML schema so far Metadata are stored in a data base (ORACLE) under two formats native XML metadata documents internal XML metadata documents native XML documents restricted to the XML elements that may be queried by the user according to an internal DTD Ancillary files linked to metadata are handled as BLOBs browse images documents

Paul Kopp – WGISS 21 4 Metadata Ingestion Metadata are created offline automatically by applications manually through a content management tool Semantic metadata validation is done offline metadata review by experts Metadata are ingested one by one or harvested syntactic validation (checking against the DTD) conversion to internal format (Xalan XSLT translator + XSL style sheet) Once ingested, metadata cannot be modified, but they can be removed, modified offline and ingested again

Paul Kopp – WGISS 21 5 Metadata retrieval Step 1 The user selects a profile (ISO 19115) or a SOF (ISO 19119) a profile is a professional view on information (e.g.: forestry, fishery) a SOF (Service Organizer Folder) is a professional view on services –concept introduced in ISO –a SOF is an aid for users in finding services applicable to their situation (ISO 19119, § 7.3.3) – a SOF may contain individual services or service chains which are seen as individual services The user selects criteria from a list of criteria available for the selected profile or SOF keywords, feature types, cloud cover, etc. Step 2 Results of the query are displayed on the users screen the user may choose among several display types (a type is identified by an XSL style sheet) –Native ISO –Dublin Core –Directory Interchange Format (DIF) All these operations are handled by the user via a Web browser (thin client) A Web server links the client to the various metadata servers requests and responses are passed over as XML SOAP messages

Paul Kopp – WGISS 21 6 Service Activation From the service metadata displayed on his screen, the user will find: the Distributed Computing Platforms (DCP) on which the service will execute the service entry point on the DCP (URL) the operations that comprise the service the parameters of each operation The user selects a DCP and provides the values needed for the operations he wants to be executed The service is activated and the results (as indicated in the ISO service metadata) are displayed in a HTML page

Paul Kopp – WGISS 21 7 Service Organizer Folder At ingest time, a service metadata is always linked to a SOF, according its category The user selects a SOF and, within the SOF, one or several categories All metadata registered in the SOF with the categories selected by the user will be retrieved SOFs are a way of defining service taxonomies CNES will use the ISO suggested taxonomy as a starting point

Paul Kopp – WGISS 21 8 Service Chaining Existing services may be chained by the service metadata administrator and are then handled as a single service This new service is linked to SOF as any other service

Paul Kopp – WGISS 21 9 Development Development funded as a CNES R&D project Implementer Same contractor as for the current ISO clearinghouse (French company) Planning Kick-off: 3Q05 Delivery: 2Q06 Concept Validation and Tests 3Q06 – 4Q06

Paul Kopp – WGISS Thank you!