Difference between revisions of "DCLite4G"
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=== FGDC === | === FGDC === | ||
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| + | == Namespace == | ||
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| + | The '''dclite4g''' namespace provides a common naming scheme for properties specific to geographic data sets and services which are not covered by the existing Dublin Core or GeoRSS standards. | ||
| + | |||
| + | The namespace will come to live at http://xmlns.com/2006/dclite4g/ . | ||
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| + | |||
| + | === dclite4g:extents === | ||
| + | |||
| + | === etc, fill in here from [[Geodata Metadata Requirements]] === | ||
== References == | == References == | ||
Revision as of 05:44, 18 December 2006
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:
TODO
- 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
ISO19115
FGDC
Namespace
The dclite4g namespace provides a common naming scheme for properties specific to geographic data sets and services which are not covered by the existing Dublin Core or GeoRSS standards.
The namespace will come to live at http://xmlns.com/2006/dclite4g/ .
dclite4g:extents
etc, fill in here from Geodata Metadata Requirements
References
- Dublin Core lite for Geo
- OGC Catalog Services 2 Specification 6.3.3, Core returnable properties
- OGC ebRIM profile of CSW specification, Appendix B.5, Table B.3 - Slots defined in the Basic package
- iGeoResourceInfo class in uDig
- GeodataCommons Metadata Whitepaper
Query Interface
OAI-PMH
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.
Others
References
- OWSCat
- Simple Catalog Interface - links to articles, etc
See Also
- http://www.geometa.info/ - German geospatial data search service using dclite4g + OAI-PMH.