real time structuring of spatial data for gis with emphasis on road features

an important issue in implementation of a gis system is preparation of data to be entered in gis. to produce spatial data for gis using photogrammetric techniques, conventional method is to apply photogrammetric and gis systems individually (off-line procedure). this approach is costly, time consuming and somehow unreliable due to the fact that 3d photogrammetric model is not available at the time of gis data structuring, to overcome these problems, editing and structuring of spatial data can be carried out simultaneously during feature digitization. feature digitizing from photogrammetric models can be performed in an interface cad environment by real time integration of photogrammetric and cad systems. based on this approach, generated data can be saved with standard structure and format defined by cad environments (e.g., micro station)and directly used for gis without further editing. in this paper, design and development of a software package called object oriented cad-based photogrammetric system (ocbps2, version 2) which integrates photomod and micro station systems in an object oriented way, is described. this system carries out real time structuring and editing of spatial data for class of road features by controlling logical relations among road class features and other features.