<title>Combined technique for 3D digital site model generation based on imagery and GIS data</title>

Abstract

Quickly growing field of planning and decision support systems require effective tools to operate with spatial distributed information. The modern virtual GIS using 3- dimensional representation of the real territories are designed to decide most problems. Nowadays because of difficulties to have a high detailed 3D digital world model due to limited computer possibilities the following way is realized. The GIS data (electronic maps) provide the stationary base with rather large step of the grid and artificial (but nature similar) textures. The space photos (especially made by the topographical camera TK-350 and camera of the high-resolution KVR-1000) are the sources of more precise models with natural gray-scale textures. The model of area in the vicinity of most interesting places can be received only by means of aerial photographs or video data processing. The accuracy of such model can achieve about several decimeters both in height and plan. The realized components of 3D site model generation technology is discussed: photogrammetric processing of initial photos to get digital elevation models of a terrain surface and 3D object geometry; construction of digital terrain models from GIS data; terrain surface textures generation; transformation of these 3D models to standard formats used by well-known systems of 3D objects and scenes construction.