"嫦娥"卫星三线阵CCD立体相机是实现月表地形观测的重要荷载,其以前、正、后视3种视角对月表进行连续扫描,获得南、北纬70°范围内3种不同倾角的二维推扫影像。在无月面控制点、卫星位置和姿态数据的条件下,基于数字摄影测量理论提出一种建立月表三维模型的方法:通过影像匹配获得前、正、后视二维推扫影像中的立体像对的像点坐标,在此基础上结合用准控制点后方交会解得的嫦娥卫星的空间位置和姿态数据,通过前方交会的方法解算出像元对应月面点的月球表面数字高程模型(DEM)径向高度数据,进而得到月表高程拟合模型、等高线分布图等,实现月表三维模型的建立。
The three array CCD stereo camera onboard the Chang' e orbitor is an important load to realize the moon terrain observation, which progressively scans the lunar surface by three kinds of angles of view, i. e. , foresight, front sight and back - sight, thus obtaining two - dimensional phantoms of three kinds of inclination angles between north latitude 70° and south latitude 70°. In the absence of exterior orientation elements and lunar ground control points, a photogrammetric method of three - dimensional modeling is put forward : Through image matching, image points of the same names in the foresight, vertical image and back -sight scanning phantoms can be found; with the exterior orientation elements at each scanning time calculated through resection and the theory of collinear equation, the three - dimensional coordinates of the points on lunar surface can be calculated ; finally, on the basis of the former results, the lunar terrain digit elevation model (DEM) radial direction altitude information can be obtained, thus the lunar terrain three - dimensional model is established.