– Free geospatial data for Greece

In a previous post (in Greek) I was complaining about the slap-dash look and feel of the free online service for viewing orthophotos provided by Ktimatologio S.A., Greece’s cadastral organization, . (You can view the site here. NOTE: You will not be impressed)

Well,  I definitely cannot say the same about the Geodata portal , Greek government’s first attempt to aggregate and provide free of charge all geospatial data generated and managed by the various public agencies.

The site, currently in Beta release, provides a simple and easy to use interface to search and download various thematic layers categorized by type and responsible agency, in shapefile, GML or KML format. It also provides a map viewer where visitors can see the data prior to downloading it.

And I guess being true to the current “Save money-we-are-in-the-midst-of-the-biggest-economic-crisis-in-recent-history motto, the whole site was built using Open Source software. Actually, the technologies used sound like a Who’s Who of OSS: Joomla, PostGIS, MapServer, OpenLayers, MapFish and GeoNetwork, they are all there!

But I think the use of OSS is more of a conscious decision rather than one dictated by cost considerations. The cost component though, comes out quite clearly in one of the FAQs explaining why the performance is sometimes slow. In their own (translated) words:

The availability of geospatial data through maps on the Internet requires a certain level of infrastructure (servers, storage) that cost a significant amount of money. Similar services in other countries are based on hardware costing several million euros. But we can not and should not burden the state budget., like most new electronic public administration services is hosted on Virtual Machines hosted on existing hardware that the civil service already owns but is not used. We continue to try and locate similar hardware and reuse it for the operation. As visits increase, we are at the same time  trying to upgrade our infrastructure with minimal cost.

But despite its less than optimal performance, its a great effort and huge kudos to the people who made it true. Keep on the good work guys!


Silverlight interface for Mapserver GIS

Yes, such a beast does exist! And I am proud to say that Gaiocorp (ok, a bit of not-so grey advertising) has developed it and released is as an open source project in CodePlex ( Lovingly called SLMapViewer, it is a reusable Silverlight map control for use with MapServer, the popular open source WebGIS. It was initially developed as  the the mapping component for some of Gaiocorp’s products and was based on the MapFlash Viewer Framework’s concept  developed by Paolo Corti. Since then it has changed almost beyond recognition, supporting a large number of ‘GIS-like’ functions, different ‘view modes’ to be used as either through a normal browser or in a street kiosk, and extendable helper classes so developers can implement their own business logic for layer display. SLMapviewer can be used as a standalone map viewer or be embedded it and thus spatially enable, ASP.NET or Silverlight applications.