ESDIN Status Report November
Script with Links
ESDIN - a short project report.
ESDIN - the European Spatial Data Infrastructure Network - is a support in action for the national mapping and cadastre agencies in Europe.
It is all about data and will be the foundation of the ermerging European Location Framework (ELF) and it's growing community.
- http://www.metaspatial.net/download/gml.png (faked image for screencast)
Data as such is hard to visualize because raw geospatial data usually looks rather disappointing to humans.
The agreed format is OGC GML - the Geographic Markup Language, an XML schema for geographic data. But there are tools that can give us more visual access to this data.
- http://www.metaspatial.net/download/ESDIN_client_authenticating.png (screenshot for screencast)
One such tool is the ESDIN Data Viewer which we want to explore a bit in this little screencast. First off we need to authenticate to be able to access protected services. As we can see this happens through a Shibboleth Identity Provider operated by our Consortium partner EDINA.
Shibboleth is a federation technology that can be used by different organizations who are all connected through a public network.
ESDIN has closely aligned this work with the OGC. The second Authentication Interoperability Experiment based on ESDIN best practices is about to start in November 2010.
Authentication and security pays tribute to the diversity of individual licensing schemes of the Consortium partners. Past experience has proven that it is difficult to harmonise the licensing policies of the European National Mapping and Cadastre Agencies.
- http://www.metaspatial.net/download/licensing_policy.png (screenshot of non-public document cover page, for podcast only) Download a slide set on the Licensing Wizard
One task of the ESDIN project has set out to address this issues and create a Best Practice for licensing policies.
EuroGeographics has contracts with it's members and can act as a single point of access to this network of services.
- http://research.geodan.nl/esdin/client_gv_dev/geoviewer/examples/esdin/ (Access to this client requires credentials to authenticate. Please contact EuroGeographics for further information.)
Now that we are authenticated we can explore the data. The current background maps are based on the known EuroGeographics products EuroBoundaryMap, EuroRegionalMap and EuroGlobalMap. These map products are compiled from member state data in a highly work intensive manual process.
One core goal of the ESDIN project is to considerably automize and enhance this process. We will look into this in another screencast.
But back to the Data Viewer. Let's use the live site and explore how the client works. Whenever the map window is updated (by zooming in or panning around) all map and data services of that area are requested to deliver their maps or their data - in the standard format OGC GML.
That is the same format required by the INSPIRE directive which means that we are actually helping to set up a compliant infrastructure, both for Download and Viewing Services.
Lets move up to Norway and Sweden and look at the Euro Regional Map. It has lakes that go across borders and must therefore belong to different NMCAs. How does this work? To visualize this we switch the base layer to show the EuroBoundaryMap which has no topographical features.
Now we activate the Hydrography theme from the INSPIRE Annex 1 list and can see that it is split into four topics. One topic is "Standing Water" with the lakes we could see in the EuroRegionalMap. When we activate this layer we can see that two services are loaded, one from Norway and one from Sweden fitting together nicely at the border.
Depending on the speed of the servers and our Internet connection we can see that the data comes in asynchronously. This shows that the data providers operate independently in a federated system. Clicking on the objects in the map shows their corresponding attributes in the data grid below the map window. We can see that we access real data, not just the map images. The exterior ring of the objects is highlighted and the data grid shows their IDs and attributes. Looking closer at the IDs reveals that they come from two member states. Those prefixed with NO come from Norway and those prefixed with an SE are from Sweden.
Well, this is all for today. Thanks for your interest and stay tuned for the next podcast on building ELF - the European Location Framework.
Further Links (not in the podcast)
Watch out, these are still work in progress!