華衛二號具有傾斜觀測之能力，故可進行立體像對之取樣。使用立體像對可對物空間進行三維之重建。所產生之數值地形模型不僅可用作華衛二號正射化幾何改正之用，尚可應用於其它空間資料之分析及三維地圖之製作。因華衛二號尚未發射，影像尚不可得，因此本計畫之目標在於使用模擬之華衛二號立體像對進行三維定位方法之建立。 研究之重點在於建立一個可供應用的方法。其主要工作構件包括：(1)影像方位參數之重建， (2)核幾何之建立，(3)影像匹配，(4)空間前方交會，及(5)網格內插以產生數值地形模型。 在品質驗證方面則需使用模擬之立體像對進行上述方法之測試。在方位求解方面將採用檢核點進行誤差評估。數值地形模型部份除少數樣點外，將以正射影像間之視差為評估重點。考慮建築區地形重建不適用前述自動化的方法，本研究不考慮此種地區之自動處理。然為分析其定位之潛力，少量以人工量測之點將用以評估其幾何品質。 Due to its side looking capability, ROCSAT-2 may acquire stereoscopic images. It is possible to reconstruct three dimensional terrain in the object space using the acquired stereopairs. Generated Digital Terrain Models (DTMs) may be used in orthorectification for ROCSAT-2 images. In addition, those data may also be used in the spatial data analysis and 3-D mapping. ROCSAT-2 images are not available at the moment, we will use simulated ROCSAT-2 images instead of a real one in the final validation. The major work is to develop a useful method for 3-D reconstruction. Major components include (1) orientation modeling for orbit parameters, (2) establishment of epipolar geometry, (3) image matching, (4) space intersection and (5) grid interpolation to generate a DTM. In the validation, we will use simulated images to test the performance for the proposed scheme. Ground check points will be used in the quality check for orientation parameters. For DTM verification, a number of ground check points will be used. In addition, the parallax between two images in a pair will also be used to indirectly check the quality of the generated DTMs. Considering the unsuitabily of automatic DTM generation for built-up areas, the stated procedure will only be applied to those non-building areas. To verify the geometric quality for built-up areas, we will test some manual measurements instead of automated ones. 研究期間：9008 ~ 9107
