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== Overview ==
 
== Overview ==
  
These are experimental pages originated from OSGeodata Mailing List on [https://geodata.osgeo.org/servlets/BrowseList?listName=geodata&by=date&paged=false OSGeo.org].
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These are experimental pages ([[OSGeodata Discovery|1]],[[OSGeodata metadata exchange model|2]],[[OSGeodata metadata exchange protocol|3]],[[OAI-PMH|4]]) originated from OSGeodata Mailing List on [https://geodata.osgeo.org/servlets/BrowseList?listName=geodata&by=date&paged=false OSGeo.org].
  
Let's finally unleash geographic information through open access and dissemination of geographic data and (metadata) search appliances!
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Let's 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)
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Allow to '''[[OSGeodata Discovery| discover geodata]]'''! Let's make metadata 'sexy' again.
 
  Therefore we urgently need a '''metadata information model''' (see below)
 
  as well as a '''metadata exchange protocol''' (see below).
 
  
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''.
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For the '''[[OSGeodata Discovery| discovery of geodata]]''' we need a
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* '''[[OSGeodataMetadataModel| Geographic metadata exchange model]]''' as well as a
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* '''[[OSGeodataMetadataProtocol| Geographic metadata exchange protocol]]''' (catalog service).  
  
== Need for a metadata exchange protocol ==
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For '''documentation''' an internal geodata management model is needed. For the '''metadata metadata exchange model''' a proposal was made called  '''[http://wiki.osgeo.org/index.php/Geodata_Metadata_Requirements#Information_model_for_metadata_exchange Dublin Core lite for Geo (DClite4G)]'''.
  
After having agreed on a better protocol there is also a need for a better name than 'Geographic Catalog Service or Protocol', like 'Geographic Metadata Harvesting Protocol'.
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Remarks: '''Metadata''' is just data about data. There is nothing special regarding its modeling and encoding. Metadata according to metadata exchange model should be strictly free (LGPL?).
  
For general '''protocol requirements''' read [[OSGeodataMetadataProtocol]].
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== Pleadings for metadata (models) and adequate protocols ==
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* ''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)
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* [http://www.digitalearth.com.au/2006/06/23/lightweight-web-resource-catalogue/ Blog 1] - "Leight Weight Web Resource Catalogue"
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* [http://geotips.blogspot.com/2006/02/more-simple-web-services-catalogues.html Blog 2] - More Simple Web Services Catalogues...", and
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* [http://www.kralidis.ca/blog/2006/08/04/geospatial-catalog-development-brewing/ Blog 3] - geospatial-catalog-development-brewing.
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* [http://home.badc.rl.ac.uk/lawrence/blog/all 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.").
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* Paper "Are Geospatial Catalogues Reaching their Goals?" from [http://www.agile2006.hu/papers/Larson_Siliceo_etal.pdf Larson et al.].
  
For proposals around the '''metadata information model''' requirements see [[OSGeodataMetadataModel]].
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== Building blocks for metadata management ==
 
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Building blocks are:
== Need for a metadata information model ==
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# A geometadata '''management model''' (e.g. internal to each organisation)
 
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# '''Tools''' to manage the geometadata
We definitively need a metadata information model. Geographic catalog is rather data provider centric name for a system and a model, so we prefer a user centric 'metadata (information) model'. See [[OSGeodataMetadataModel]] for further discussion.
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# A geometadata '''[[OSGeodata metadata exchange model| exchange model]]'''
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# An '''encoding''' of the geometadata exchange model (probably XML)
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# Geometadata '''[[OSGeodata metadata exchange protocol| exchange protocols]]''' (like [[OAI-PMH]], see [[OSGeodata_Discovery]])
  
 
== Weblinks ==
 
== Weblinks ==
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* [http://wiki.osgeo.org/index.php/Geodata_Metadata_Requirements#Discovery Wiki at osgeo.org] for requirements
 
* [http://wiki.osgeo.org/index.php/Geodata_Metadata_Requirements#Discovery Wiki at osgeo.org] for requirements
 
* [https://geodata.osgeo.org/servlets/BrowseList?listName=geodata Geodata mailing list at osgeo.org] for discussions
 
* [https://geodata.osgeo.org/servlets/BrowseList?listName=geodata Geodata mailing list at osgeo.org] for discussions
* Pleadings... [http://www.digitalearth.com.au/2006/06/23/lightweight-web-resource-catalogue/ Blog 1] - "Leight Weight Web Resource Catalogue",  [http://geotips.blogspot.com/2006/02/more-simple-web-services-catalogues.html Blog 2] - More Simple Web Services Catalogues...", and [http://www.kralidis.ca/blog/2006/08/04/geospatial-catalog-development-brewing/ Blog 3].
 
  
Geographic information search services:
 
* Catalogs:
 
** [http://www.mapdex.org mapdex.org]
 
** [http://www.geographynetwork.com ESRI's geography network]
 
** National Portals: [http://www.geodata.gov US], [http://geodiscover.cgdi.ca CA], [http://eu-geoportal.jrc.it EU], [http://www.gogeo.ac.uk UK], [http://www.geocatalogue.fr FR], [http://www.geoportal.bund.de DE], [http://www.geoland.at AT], [http://www.geocat.ch CH]
 
* Search engines:
 
** General: [http://maps.google.com/ Google Maps], MSN live, Yahoo!
 
** Specialized: [http://www.geometa.info geometa.info] (still german only for linguistic processing reasons)
 
* GIS with catalog and search components:
 
** [http://udig.refractions.net uDig], ArcGIS, ...?
 
  
 
<!-- Kategorien und ev. Koordinaten -->
 
<!-- Kategorien und ev. Koordinaten -->
[[Kategorie: Geodaten]]
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[[Kategorie: Geodaten]] [[Kategorie: Metadaten]] [[Kategorie: English]]

Aktuelle Version vom 29. Oktober 2006, 12:15 Uhr

Overview

These are experimental pages (1,2,3,4) originated from OSGeodata Mailing List on OSGeo.org.

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

Allow to discover geodata! Let's make metadata 'sexy' again.

For the discovery of geodata we need a

For documentation an internal geodata management model is needed. For the metadata metadata exchange model a proposal was made called Dublin Core lite for Geo (DClite4G).

Remarks: Metadata is just data about data. There is nothing 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: