多面函数光滑因子对GPS高程转换精度影响分析

Analysis of the Smooth Factor on the Precision of GPS Height Transformation by Hardy Function

利用多面函数进行GPS水准高程转换,通过大量试验总结出:对于正双曲面核函数来说,拟合精度随着光滑因子的增大而提高;对于倒双曲面核函数,光滑因子存在极大值,超过这个值拟合精度就会降低。总结出利用多面函数进行GPS高程拟合光滑因子的影响规律,解决了在利用多面函数进行GPS水准拟合时由于光滑因子不能准确确定致使精度不稳定的问题。

Hardy function is used to transform the GPS leveling height,and it is summed up through some experiments that: For the kernel function of positive hyperboloid,the fitting precision improves with the smooth factor increased;but for the inverse hyperboloid,the smooth factor has a maximum,if we use bigger smooth factor than the maximum,the fitting precision will reduce.We summed up the influence rule of smooth factor using hardy function in GPS height fitting to solve the problem that smoothing factor should not determine precisely as a result of the accuracy of instability in GPS level fitting.