OSGeodata: Unterschied zwischen den Versionen

Version vom 5. September 2006, 13:17 Uhr

Overview

These are experimental pages (1,2,3,4) 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!

For the discovery of geodata we need a

• Geographic metadata exchange model as well as a
• Geographic metadata exchange protocol (catalog service).

For documentation an internal geodata management model is needed.

Remarks: Metadata is just data about data, so nothing is special regarding its modeling and encoding. Metadata according to metadata exchange model should be strictly free (LGPL?).

Pleadings for metadata (models) and adequate protocols

• 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)
• Blog 1 - "Leight Weight Web Resource Catalogue"
• Blog 2 - More Simple Web Services Catalogues...", and
• Blog 3 - geospatial-catalog-development-brewing.
• Bryan's Blog: "To extend or not to extend ..." ("In practice, we can exchange any derivative of the ISO19139 profiles using OAI and store them in xml databases.").
• Paper "Are Geospatial Catalogues Reaching their Goals?" from Larson et al..

Building blocks for metadata management

Building blocks are:

1. A geometadata management model (e.g. internal to each organisation)
2. Tools to manage the geometadata
3. A geometadata exchange model
4. An encoding of the geometadata exchange model (probably XML)
5. Geometadata exchange protocols (like OAI-PMH, see OSGeodata_Discovery)

Weblinks

Information:

• Wiki at osgeo.org for requirements
• Geodata mailing list at osgeo.org for discussions