基于IGGⅢ方案的加权总体最小二乘点云球面拟合

Fitting of sphere point clouds by weighted total least squares based on IGGⅢ scheme

为了减少测量粗差对球标靶拟合精度的影响,在加权总体最小二乘法基础上,针对地面3维激光扫描球标靶数据特点,采用了权函数IGGⅢ方案,自适应地修正拟合权阵,构建了新的点云球面拟合方法。利用新方法分别拟合了模拟球面数据、实际扫描球面数据。结果表明,该方法在同时考虑拟合模型系数矩阵误差与观测向量误差基础上,通过合理定义及优化拟合权阵,获得了更为精确的球面参量。其拟合评价指标均优于常规方法。

In order to decrease the influence of observational gross error on the fitting precision of sphere target, aiming at data characteristics of sphere target by terrestrial 3-D laser scanning and based on weighted total least squares, weight function IGG Ⅲ scheme was adopted to adaptively modify the fitting weight matrix and a new fitting method of sphere point clouds was proposed.Simulated spherical datas and scanning spherical datas were fitted separately with the new method.The results show that, based on the consideration of both observation vector error and coefficient matrix error, more accurate sphere parameters are obtained by means of reasonable definition and optimization of fitting weight matrix.The fitting evaluation index of the new method is better than the conventional method''s.