抗差估计中几种选权迭代法常数选取的探讨

常规抗差估计中采用选权迭代法时常数的取值是否合理直接关系到平差过程能否顺利进行和平差结果的优劣,本文通过对目前几种选权迭代法中常数的选取进行研究;得出:常数按K1=m ax(|(v1-l1)|)、C=m ax(|(vi-li)|)取值时,能有效解决常规取值方法(K1=3.0~8.0或K1=3.0~6.0,C=8)在粗差较大时出现秩亏、法方程系数矩阵奇异的现象,导致平差不能进行或者平差结果出现严重扭曲的问题,同时本文论述了在确保有解的情况下得到最优解的处理方法。

Discussion for the selection of constant in selecting weight iteration method in robust estimation

In the normal Robust Estimation,whether the constant's selection is rational in the method of selecting weight iteration straightly relates to the adjusting process and its result.In this paper,based on the study of several popular methods of selecting weight iterations,the authors put forward a selecting method: and,the problem that adjusting can not be carried out or the result of adjusting are severe wrong has been solved.This problem is due to the rank-defect and the singular phenomena of coefficient matrix of normal equation when the gross error were too bigger in ordinary method of selecting values(or,).At the same time,this paper discusses the method that can find the best value when values are existed.