CNES implementation of the ISO 19119 standard

An extension of the current CNES implementation of theISO 19115 metadata standard

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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 19115 metadata), or relevant to services (ISO 19119 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)

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How does it work?

■ ISO 19115 & ISO 19119 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

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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

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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 19119– ‘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 user’s screen

the user may choose among several display types (a type is identified by an XSL style sheet)– Native ISO 19115– 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

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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 19119 service metadata) are displayed in a HTML page

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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 19119 suggested taxonomy as a starting point

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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

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Development

■Development funded as a CNES R&D project■ Implementer

Same contractor as for the current ISO 19115 clearinghouse(French company)

■Planning Kick-off: 3Q05 Delivery: 2Q06 Concept Validation and Tests 3Q06 – 4Q06

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Thank you!