The story of the GeoToolKit -: An object-oriented geodatabase kernel system

The quickly increasing number of spatio-temporal applications in fields like environmental monitoring, geology and mobile communication is a new challenge to the development of geodatabases. However, the query functionality of today's geo-information systems is still limited to the thematic attributes of spatial objects and to spatial 2-D objects. This article reports on GeoToolKit, an object-oriented geo-database kernel system developed at Bonn University to support 3-D/4-D geological applications. GeoToolKit is not a GIS-in-a-box package, but rather a library of C + + classes that allows the incorporation of spatio-temporal functionality within an application. Being a component toolkit, it encourages the development and deployment of re-usable and open software. The history, concepts and implementation of GeoToolKit are discussed in detail. Performance tests underline the practicability of the concepts. Extensions to and experiences with GeoToolKit applications like GeoStore, GeoWeb and WellStore are presented. Finally, we give an outlook on our future research introducing GeoToolKit as a 3-D/4-D database component within a network of distributed and mobile geo-information services.