Concepts for the Representation, Storage, and Retrieval of Spatio-Temporal Objects in 3D/4D Geo-Informations-Systems

The quickly increasing number of spatio-temporal applications in fields like environmental management or geology is a new challenge to the development of database systems. This thesis addresses three areas of the problem of integrating spatio-temporal objects into databases. First, a new representational model for continuously changing, spatial 3D objects is introduced and transferred into a small system of classes within an object-oriented database framework. The model extends simplicial cell complexes to the spatio-temporal setting. The problem of closure under certain operations is investigated. Second, internal data structures are introduced that represent instances of the (user-level) spatio-temporal classes. A new technique provides a compromise between compact storage and efficient retrieval of spatio-temporal objects. These structures correspond to temporal graphs and support updates as well as the maintainance of connected components over time. Third, it is shown how to realise further operations on the new type of objects. Among these operations are range queries, intersection tests, and the Euclidean distance function

Examination of Database Supported Spatio-Temporal Intersection Queries

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 geo-databases. However, the query functionality of todays geo-information systems is still limited to the thematic attributes of spatial objects and to spatial 2D objects. In this paper we present two examples for the definition and database implementation of spatiotemporal intersection operations to be used in geo-scientific 3D/4D applications: the intersection of a spatio-temporal object with a given axis-aligned bounding box and the intersection of a spatio-temporal object with a user-defined 3D plane. Both operations are implemented within the GeoToolKit project. We then show the application of the two operations within two geoscientific applications: the balanced restoration of the Lower Rhine Basin and the generation of artificial, time-dependent landform data in 3D space, respectively. Finally, we give an outlook on our future research work on spatio-temporal database operations