3D data acquisition and modelling in a Topographic Information System

The acquisition of 3D data and their integration in information systems which are mainly used for topographic issues are very increasing in the last years. The enlarged needs in 3D information appear with the development of the complexity of the processings in topographic information systems. The middle-sized and big cities, which have a large extent, have also important care for fitting out and want to dispose and make use of as complete as possible datasets. These datasets should integrate the third dimension. For responding to such a sort of new needs, the group "Photogrammetry and Geomatics" of the LERGEC-ENSAIS Laboratory of the ENSAIS works in the definition and the testing a 3D modelling of objects in urban landscapes. This modelling is then implemented and tested in a topographic information system coupled with an experimental digital stereophotogrammetry software, TIPHON developed at ENSAIS. This digital system makes it possible to acquire rationally geometric data, and in the same way to learn the different steps of the orientation of the digital stereopairs and the processing of stereoplotting.