Data Discovery Boulder, CO May 15, 2006 Scott Ritz Atmospheric Science Coordinator NASA Global Change Master Directory
Outline OAI-PMH (Open Archives Initiative Protocol for Metadata Harvesting) Mapserver Open API (Application Program Interface) SOAP Portals DIF Format
Computer running harvester software OAI-PMH Architecture OAI-PMH Repository Computer running harvester software Why OAI-PMH? OAI Server independent of main database Administrator controls metadata availability Queries standardized Software is open source Metadata Compatibility Dublin Core, FGDC, DIF, ISO-19115 XSLT or XML Schema II. Harvesting Process Metadata subset transferred from a database to a repository Metadata is harvested from the repository I. Database
Harvest THREDDS Metadata using OAI/PMH DLESE OAI/PMH Harvester 2. Monitor Harvest Status 3. Upload XML to a database 1. Automatic/Manual Harvest
Harvest THREDDS Metadata using OAI/PMH 4. View harvested metadata in the GCMD Titles Display DIF Display Access THREDDS Data
Access mapserver through GCMD GIS Server Portal or directly from mapserver.
Prototype Mapserver Interoperability Access GCMD’s Web Mapping Service (WMS) through an OGC WMS GET Capabilities Request. OGC WMS compatible clients can access GCMD’s map services. User Friendly Desktop Internet GIS (WMS Client) GCMD Mapserver
Open API DODS/OPeNDAP uses the GCMD open API and servlets to query the GCMD directly The “Search” frame provides interfaces to the GCMD’s MDServer through APIs HTTP Protocol
SOAP Initiative Initial SOAP Server and Client were created by Viktor Pusztai. Documentation, JUnit tests, and Web GUI to test the Client were later added. Future: Modify to follow security standards for web services (ex. user authentication, encrypted passwords ) Modify to offer different web services to serve specific needs. (ex. MetadataWebService, ValidsWebService, ServicesWebService, SubscriptionWebService, MetricsWebService, etc.)
Operations Available in Current Server Valid Operations getValids getPersonnel createValid removeValid Document Operations createDocument getDocument getDocumentList removeDocument convertDocument validateDocument Access valids or request documents from the database
Operations Available in Current Server Personnel Operations createPerson findPerson getClosePersons getPersons mergePerson removePerson Other Operations getCoordList getDateTime getDocumentList getNodeName getWebServerName getWebServerPort isAlive supportsSERF
Portals
Portals
DIF/SERF
Questions? ritz@gcmd.nasa.gov 301-867-2082