以三維建物模型進行遙測影像幾何校正之研究

Since the successful launch in 2004, the FORMOSAT-II satellite has acquired a great number of remote sensed images of Taiwan. Benefit from its daily re-visit characteristics, the FORMOSAT-II images are very useful for land cover monitoring and change detection, which inspires us for this integrated project proposal. However, the satellite image has to be corrected and registered to the consistent datum coordinate system before it can be interpreted or superimposed onto other maps. Current approaches for geometric correction rely on manually measurements of huge amount of control points, which is the bottleneck of the satellite image processing. The goal of this project is to develop an ad-hoc Least-squares Model-image Fitting (LSMIF) algorithm to semi-automatically determine the orientation parameters of the FORMOSAT-II images. In other words, the images are geometrically corrected by 3D building models instead of control points. Since the operator only has to identify each 3D building model and its approximately position on the image, the efficiency of the manual process can be improved. We will develop a proto-type system to verify the proposed algorithm and the semi-automated strategy. The results will be evaluated by two means. First, the coordinates of the check points on the geometrically corrected image will be compared to their coordinates on the topographic map. Second, the geometrically corrected images will be compared to the level 3 and level 4 images corrected by current approaches. The proposed semi-automated approach not only improves the image processing efficiency of other sub-projects, but also decreases their cost. If the capability of the proposed approach can be proved on the FORMOSAT-II satellite images, it should be also capable for the upcoming FORMOSAT-V satellite images.