坐标转换解算中基于验前中误差的稳健估计

通过公共点求解坐标转换参数时,如果公共坐标含有粗差,将会影响参数的求解,进而导致坐标转换结果产生较大的偏差。通过对比分析含粗差时的坐标中误差与验前中误差之间的比例关系,探究了坐标转换中利用离散的阈值函数与各点位较差的对比关系,判断是否含粗差,以及观测数据含粗差时,各个点位坐标较差与最大点位坐标较差的关系,并且通过权变换避免了有效坐标的权误置零的情况,通过大量数据验证了算法的有效性。

Robust Estimation of Coordinate Transfer Based on Prior MSE

Outliers in common points greatly influence the calculation resuh to get the coordinate transformation pa rameters and result in large deviation of coordinate transfer. Comparative analysis was made on the multiple relations between the posteriori MSE of coordinate involving outliers and the priori MSE. The selection of threshold was studied in comparison with the point positional errors to judge whether there are outliers or not. Besides, the relationship among the point positional errors involving outliers with the max of point positional error was obtained. Weight transformation was used to avoid the risk of the observed weight of available coordinate value being wrongly set zero. Adequate test data verify the efficiency of this algorithm.