A multi-sensor system for positioning in urban environments

Within the article a low-cost system for the provision of georeferenced terrestrial images in urban environments is presented. Based on an image with approximate exterior orientation from a low-cost GPS and a digital compass and a 3D CAD model of a visible model as provided from a 3D virtual city model, the exact location of the building in the image is detected automatically and used for a refined orientation of the image. The work is part of a project aiming on the development of a mobile device, which enables access to location-based services in a complex urban environment. The intuitive access to object-related information is realized by so-called telepointing. For this purpose, a spatial model of the user's environment is mapped to an oriented image, allowing for the access to object-related information by pointing to the respective image sections. Since the provision of location-based services currently is one of the most promising markets for the use of spatial data in urban areas, these applications will also be discussed.