POS数据用于立体模型恢复时的上下视差分析

Analysis of Y-Parallax of Stereo Model Reconstructed Using Elements of Exterior Orientation Determined by Position and Orientation System

从连续法相对定向原理出发,推导了直接由像片外方位元素恢复立体模型时模型点上下视差的计算公式,用模拟数据验证了计算方法的正确性,并对两组不同摄影比例尺的实际航摄像片进行了试验。通过比较利用GPS辅助光束法区域网平差获得的像片外方位元素和POS提供的像片外方位元素重建立体模型所产生的模型上下视差,分析了POS系统误差对模型上下视差的影响。结果表明,直接利用POS提供的像片外方位元素进行安置元素测图会出现作业员难以忍受的模型上下视差,不能满足地形测图的规范要求。

According to the principle of analytical subsequent relative orientation, the formula of vertical parallax on corresponding point is deduced when stereo model is reconstructed by using the elements of exterior orientation of images. The method is verified by simulative images and tested by two kinds of different scale images taken from Xinjiang and Qianxi, China. Compared the vertical parallax of models reconstructed by using the elements of exterior orientation obtained by GPS-supported bundle block adjustment with that determined by position and orientation system （POS）, the vertical parallaxes of models are analyzed. The experiments have shown that the vertical parallaxes of stereo models computed with POS elements of exterior orientation are intolerable. Therefore, how to eliminate vertical parallax is very important for the direct georeferencing and cartography of reconstructing stereo models.