Exploitation of GPS Controlled Imagery

The proposed research focuses on the development of new technology for the automatic orientation of GPS controlled aerial imagery, the online creation of digital surface models and orthophotos, the comparison of images collected at different time periods for change detection, and the archiving of these images in a spatial database. To achieve these goals the exterior orientation of the airborne camera has to be computed automatically. TRANSMAP will investigate methods for automatically measuring conjugate points in overlapping images to compute a photogrammetric triangulation with known GPS exposure coordinates. The oriented images will be used to automatically extract DEMs by image matching, to produce digital orthophotos and surface models, and to detect changes at the terrain surface using images of different epochs. Methods for spatially indexing digital imagery and storing them in GIS databases will be studied. To improve the orientation accuracy and the reliability of the automated methods auxiliary sensors may be added to the system. Laser scanners will be used to automatically create DEM's from large scale images, and inertial systems are necessary to determine the rotation angles of the camera with a high degree of precision. The new system will be able to create digital surface models on line without user intervention.