GPS测定正常高的方法研究

The research of finding the solution of normal height with GPS

对GPS在水准方面的应用现状作了简单的介绍 ,综述了近年来用GPS求定正常高的各种几种方法 ,即多项曲线拟合、多项式曲面拟合、多面函数曲面拟合、加权均值法、非参数回归法和高程异常变化梯度法、固定边界三次样条插值法、线性移动拟合法、神经网络法、非格网GPS散点数据考虑地形改正法。但是在拟合法求定正常高的过程中还存在一些问题 ,如 :未考虑各种方法使用的条件 ;未对GPS重合水准点进行可靠性检验 ;在转换之前未进行坐标旋转 ;没有考虑本地椭球面与WGS -84椭球面的差异和GPS网中水准点的选择与分布。只有考虑这些因素的影响 ,经转换后高程方可达厘米级精度。

The paper briefly introduces the present application of GPS-leveling,and various goemetrical methods of finding solution of normal height with GPS in recent years.That is polynomial curvilinear fit,many-sided curve fit,many-sided function curve fit,weighted average,non-parameter regression and abnormal height varied gradient,fixed boundary cubic spline,linear-moved fit,nerve network,non-grid dispersed data which consider terrain's correction in GPS leveling.But there are some problems with fit methods,such as not considering the condition of using various methods,not testing the reliability of the repeated GPS leveling,the coordinates not rotated before derivation,not considering the difference of the area elliptical sphere's surface and WGS-84's,and not considering the leveling point selection and distribution in GPS net.Only these factors considered can cm level accuracy of the derived height be obtained.