3d-Gis for Urban Purposes

New developments in urban planning, especially in environmentally oriented analysis including noise, air pollution, urban climate etc., call for new demands on authorities and planners. Due to the increasing availability of informations systems and of 3D-data, planners and municipalities emphasize modeling the urban space in three dimensions. While the visualization aspect is often and detailed considered, only a few investigations about interactive aspects on urban planning are available. In this paper we present a framework for a 3D-urban-GIS. This includes conceptual aspects and a ®rst outline and implementation of an application prototype. For this representation, new scopes have to be considered from data acquisition to modeling and to storage. First, the urban object space is classi®ed in an hierarchical 3D object structure. In accordance to different planning levels (i.e., levels-of-detail), several data acquisition methods are fused to obtain 3D datasets. The results show that a context speci®c methodology has to be de®ned. This includes planning aspects that are traditionally not available in GIS. Based on test sites in Rostock and Stuttgart, a 3Durban-GIS prototype is in development, joining aspects of a 3D-visualization interface and a database for 3D objects.