The aim of this diploma thesis was to develop an efficient viewer for INTERLIS data based on a Web Map Server (WMS). This comprised on the one hand the development of an efficient client to the existing open-source Map-Server of UMN (University of Minnesota). A second part was to develop an import-tool for the UMN Map-Server in order to load INTERLIS data.

The client communicates with the Map-Server through the Web-Map-Server (WMS) interface specified by the Open GIS Consortium and supported by most of the Map-Servers. Another advantage of WMS over HTML is the ability to get an image a single request. In order to compensate for the long response time of the Map-Servers (several seconds) we implemented a preloading scheme. This allows for an immediate update of the view after a shift of the map section. In addition we implemented a caching algorithm that allows browsing through the last ten map views. The viewer client is also able to combine data originating from different servers. Finally the user can attach simple graphic objects (line, rectangle, circle and text) to the map, which keep aligned with the map when the view is shifted or scaled. The image can be printed or saved in GIF-format.

The UMN Map-Server has the ability to work with different data sources. One of these is the open-source PostGreSQL DB with the PostGIS extension. With this database we implemented in the second part of our thesis a converter that transforms the INTERLIS data model to an SQL script in order to create the corresponding tables. With the same tool it is then possible to convert the INTERLIS XML-datasets into INSERT statements for the PostGreSQL DB. One of the major difficulties thereby were the mapping of the OO-INTERLIS-scheme to an ER-scheme as well as the transformation of the INTERLIS attributes into adequate database equivalents.