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== Need for a metadata information model ==
 
== Need for a metadata information model ==
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The currently proposed ISO 19115 spec. has mainly two weaknesses: It is too complex (even the core) and it does not cover service description. Extending an already heavyweight spec. probably does'nt make it more lightweight.
  
 
We definitively need a metadata information model. a metadata model is nothing else than a usual information model. Information models are the basis for capturing data, database management as well as for data exchange protocols. This metadata information model should be lightweight and should describe geographic resources being primary data but also filter services.
 
We definitively need a metadata information model. a metadata model is nothing else than a usual information model. Information models are the basis for capturing data, database management as well as for data exchange protocols. This metadata information model should be lightweight and should describe geographic resources being primary data but also filter services.
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;Service as own resource or as attribute value to data resource?: There is a dilemma about what constitutes a 'resource' the metadata points to: Is a geographic service, like WMS, a resource on its own? In this case a harvester must subsequently try to request it for more information based on the indicated protocol hopefully indicated by a type value. If the geographic data remains the single source of resource, every file format (like GeoRSS, GML, DXF, Shapefile) as well a service type, like a 'WMS layer' or a 'WFS feature set' needs to be mentioned in the metadata record.
 
  
 
See [[OSGeodataMetadataModel]] for further discussion.
 
See [[OSGeodataMetadataModel]] for further discussion.

Version vom 16. August 2006, 10:25 Uhr

These pages are about our search of "a protocol for the incremental exchange of metadata about geographic resources between systems" which is open, lean and mean. Proposals like OGC's CSW 2.0 do not fulfill these requirements. Profiled specifications like WFS or OAI-PMH (see below) are currently on our short list.

These are experimental pages originated from OSGeodata Mailing List on OSGeo.org.

Let's finally unleash geographic information through open access and dissemination of geographic data and (metadata) search appliances!

Managing metadata well is the key to making a repository of open geographic data really useful and re-usable. Creating metadata can be a dull chore. Part of the problem is over-focus on production, rather than consumption; on standards, rather than on usage. The Geodata Committee at OSGeo has been working on a "simplest useful thing" approach to geographic metadata.... (Citation from Jo Walsh)

Keywords: Open access to and dissemination of geographic data (geodata) and information; Metadata; Finding, harvesting or discovery of geodata and web map services; Interoperability; Integration; Service binding; Spatial data infrastructure; Standards.


Towards a new geographic catalog protocol...

For protocol requirements read the OSGeodata Mailing List mentioned above, for requirements of the metadata information model (e.g. for response data) see this OSGeo Wiki page as well as the OSGeodataMetadataModel.

Search or harvest protocol?
Do we look for a metadata query/search protocol or a metadata harvesting procotol? See OAI-PMH for a possible solution.

Better name sought:

  1. Geographic Metadata Syndication Protocol
  2. Geographic Metadata Harvesting Protocol
  • Other proposals?
    • Geographic Data Discovery Protocol
    • Geographic Metadata Dissemination Protocol
    • ...?

Need for a metadata information model

The currently proposed ISO 19115 spec. has mainly two weaknesses: It is too complex (even the core) and it does not cover service description. Extending an already heavyweight spec. probably does'nt make it more lightweight.

We definitively need a metadata information model. a metadata model is nothing else than a usual information model. Information models are the basis for capturing data, database management as well as for data exchange protocols. This metadata information model should be lightweight and should describe geographic resources being primary data but also filter services.

See OSGeodataMetadataModel for further discussion.

Weblinks

Information:

Geographic information search services:

Specifiations:

  • OGC's CSW 2.0
  • OGC's WFS
  • OAI-PMH - including home, wikipedia, documents, tutorials, tools and demos
Von «https://giswiki.hsr.ch/index.php?title=OSGeodata&oldid=2928»