From OSGeo
Revision as of 11:00, 16 December 2006 by Wiki-JoWalsh (talk | contribs)
Jump to navigation Jump to search

DCLite4G is an effort to

  • establish a common information model with mappings to well known formats for geospatial metadata
  • provide a vocabulary/recommendations for spatial extensions to Dublin Core
  • support simple interfaces for collecting and querying geospatial metadata

Getting involved

Mailing List

Feel welcome to join the discussion and development mailing list:


  • extract more of the specifics from Geodata Metadata Requirements. (This has changed a lot from the original version in the history & current version which has data sets differentiated from data sources, which may be files or databases or services)
  • update docs on Geodata Metadata Model
  • draw some UML to appease people?

Information Model

Core Model

Dublin Core




Query Interface


The Harvesting Protocol (version 2.0) specification together with Implementation Guidelines

Following are specific guidelines for a minimal OAI-PMH implementation of a so called 'data provider' using only the mandatory 'unqualified' Dublin Core (DC):

  • Only three operations (verbs) are needed: Identify, ListMetadataFormats and ListRecords.
  • Following operations are not required (initially): ListIdentifiers, ListSets, GetRecord.
  • No incremental harvesting (resumption process for ListXxx operations with more than 1000 records)
  • No compression as defined in the OAI-PMH spec. (compression at lower http level still possible)
  • Date granularity may be 'day' not seconds (YYYY-MM-DD)
  • Keeping track of deleted record may not be supported (deletedRecord=no)
  • Mandatory DC supported as data model is sufficient for a start but with specific semantics (e.g. coverage, relation) (see also example below):
    • dc:description contains dct:abstract
    • dc:coverage contains bounding box encoding as defined in http://georss.org/simple.html#Box
    • dc:date means in fact dct:modified
    • dc:relation is filled in with dclite4g:onLineSrc. If dc:type='service' dct:hasPart can be derived from GetCapabilities.

Additional bounding box query property for ListRecords.



See Also