根据ALOS卫星全色遥感立体测绘仪(PRISM)传感器的成像原理,利用卫星影像的辅助数据文件构建无需地面点的严格几何模型。试验发现,直接利用星上提供的轨道姿态数据和严格几何模型进行无控制定位精度较差,经分析发现ALOS卫星辅助数据文件中提供的CCD侧视角可能存在固定的系统误差,经校正后能使定位精度得到显著提高,达到ALOS卫星标称的几何定位精度。不同景影像定位精度的差异可能的原因是CCD侧视角的细微变化。
Based on the principle of ALOS PRISM, a rigorous geometric model is established by imagery ancillary data. This progress can be seen as a series of coordinate system transformation, Then we use the rigorous geometric model to achieve for georeferencing of ALOS/PRISM imagery. Experimental results show that there would be constant systematic errors existed in side watch angle. In order to eliminate the systematic error, a new matrix was introduced. It is used to rectify the look direction in ECR coordinates. Once the systematic errors are eliminated, the result is improved noticeably. Accuracy is better than 5 m for the planar position and 3 m for the altitude. It shows that the improved rigorous geometric model is very stable and the accuracy of direct georeferencing is also very ideal. However, in different areas, the accuracy isa little different. The result shows that the change of side watch angle may act on the final orientation accuracy.