顾及2套坐标误差的三维坐标变换方法

探讨顾及2套坐标误差改正数的三维坐标转换模型,以2套坐标改正数的加权平方和最小为准则导出了转换参数的解算公式;并根据公共点的坐标改正数以及公共点与待转换点间的协方差阵计算待转换点的坐标改正数并对其改正,从而求得近似无缝的坐标转换结果.试验表明:当公共点与转换点坐标相关性较大时,该方法能显著地提高坐标转换精度.

Three dimensional Coordinate Transformation with Consideration of Coordinate Errors in Two Coordinate Systems

Three-dimensional coordinate transformation model has been widely used in geodesy. The coordinates in both coordinate systems for computing transformation parameters are inevitably contaminated by random errors. However the coordinate errors in only one system are taken into account. In this paper, we propose a new coordinate transformation model considering the coordinate errors in both coordinate systems. The computation formulae of transformation parameters are derived based on the minimization of weighted sum of coordinate corrections in two systems. In addition, we compute the coordinate corrections of transformed points according to the covariance matrix of coordinates between public and transformed points using least-squares collocation method. The experiments show that the new model can significantly improve the precision of the coordinate transformation especially in case that the strong correletion is existent between public and transformed coordinates.