OVERVIEW OF EUROPEAN DEVELOPMENTS IN DIGITAL PHOTOGRAMMETRIC WORKSTATIONS

The current position of European Softcopy or Digital Photogrammetric Workstations (DPWS) in terms of operational systems as well as research and development activities is reviewed. European manufacturers (Leica, Matra, Galileo Siscam) have made significant strides in developing universal type DPWS for topographic applications. Operational close-range DPWS include the MAP VISION system and the Rolleimetric RS product line. European mapping organizations such as the Ordnance Survey (United Kingdom), the Institut Geographique National (France), the Institut Cartografic de Catalunya (Spain), the Landesvermessungsamt Nordrhein-Westfalen (Germany), and Eurosense (Belgium) have made first steps in using DPWS in the production environment, mainly for the automatic computation of digital terrain models and for orthoprojection. Within the universities there has been considerable research activity concerning design issues of DPWS, often focusing on specific applications. For example, work is in progress in Berlin, Glasgow, Hannover, and London on topographic applications, in Braunschweig and Zurich on close-range applications, and in Graz, London and Oberpfaffenhofen on radargrammetry. Similarly, a body of work on algorithmic aspects of DPWS has been carried out in Bonn, Darmstadt, Delft, Enschede, Karlsruhe, Lausanne, Munich, Stockholm, Stuttgart, and Zurich. These activities are reviewed and lead to a number of conclusions on the state-of-the-art and on future trends. The major ones are A DPWS is and will remain an interactive workstation, where the human operator handles less and less routine work, but stays responsible for verification and control. Digital orthoprojection is on the verge of becoming widely used in practice. Image matching techniques are applied in a number of DPWS for small-scale applications. The use of operational image understanding methods in DPWS has not yet been achieved. The incorporation of data from different sources, for example, optical and microwave imagery, is increasingly being recognized, as is the connection between DPWS and GIS.