Theodolit-based and Knowledge-based Multi-Sensor-System

Planners in industry and governmental offices increasingly need 3D representations of objects in the built environment. Theodolite and image-based measuremement systems, using videometric methods, can help to fulfill these standards. The CCD-camera of the theodolites is capable of capturing mosaic panorama images by camera rotation. The georeferenced images can then directly be used for deformation measurements and object reconstruction. Several theodolite measurement systems were developed, however all these industrial measurement systems can only be applied if artificial targets define the points on the objects to be monitored. With this project shall be shown that a larger set of working modes can be accomplished, if the information contained in the digital images is utilized in a more flexible way. In this case a two-step approach is straightforward: 1. Detect points of interest that serve as candidates for high accuracy object reconstruction. 2. Search corresponding points in the image of the second theodolite to gain 3D data (matching). Several working modes for interes point finding and matching will be applied. Some of these working modes are based on the assumption that there are pattern on the objectsurface to be scanned, others do not need any texture. Such a theodolite measurement system is uncommonly complicated to use and will request certain skill and experience of the operator for proper selection of the measurement mode. It thus appears that this process should be supported by a knowledge-based system component for decision making. There are two components beside the operator: a Knowledge-Based System for decision support and the Videotheodolite Processing and Control. The first phase of the project will contain an extensive analysis of the problem and the knowledge that is needed for obtaining meaningful solutions. In the next phase a suitable model for representing the knowledge will be investigated. Finally tests shall demonstrate the advantages of knowledge base measurement systems.