Conference Paper

The former German Democratic Republic (GDR) was very active prospecting their territory for commercially attractive minerals and other deposits. From the 1950s to the 1980s the GDR put down numerous boreholes and used refraction seismic to gather information about the deep underground. This abundance of data has been available for decades in the archives of the involved organisations but access was only possible for specialists equipped with expensive software that required expert training.

A few years ago the federal state of Brandenburg, represented by the regional geological survey (Landesamt für Bergbau, Geologie und Rohstoffe (LBGR)), decided to make this data more easily available to experts but also the public in general. After securing considerable funding from the European Union (EU) a call for tenders was issued requesting a browser-based application solely utilizing Open Source Software.

This talk will present the solution developed for this question: The used OpenSource components include OpenLayers, GeoExt 2, ExtJS 4, X3DOM, PostGIS 2 and GeoServer.

The geological data representing boreholes, depth profiles and geological layer (as well as some background-data such as topographical maps) were set up as services, mainly in a PostgreSQL / PostGIS 2 and GeoServer environment. For the three dimensional data we utilized the W3DS (Web 3D Service) which publishes the data as a scene graph and enables us to interact and navigate in this scene in the browser. The base library of the client is the framework X3DOM, which we connected with ExtJS through a newly-developed custom library. This makes communication between these parts easier. The webclient is working solely with JavaScript, there is no need for a browser-plugin.

Main focus of the talk will be the technical foundation of the solution and the 3D-client functionality:
- Generating virtual geological boreholes for any place on the map
- Generating virtual geological cross-sections between two coordinates
- Get information and charts about the fixed sets of boreholes
- Complex searches combining multiple attributes of the data
- Interactively navigate to a region of interest in the 2D-client and instanciate the 3D-client for this region