中文摘要：

提出一种新的内插方法求解流动站的对流层天顶延迟量（ZTD），该方法基于泰勒级数展开式推导得到顾及高阶展开项的反距离加权内插公式。对于高程较为突出的流动站，结合投影延拓处理方法可有效改善ZTD的内插精度。利用SCIGN的实测GPS数据的实验结果表明：在一定区域范围内，基于高阶泰勒级数展开的反距离加权法求解流动站ZTD的精度明显优于传统的反距离加权法，对于高海拔流动站的精度改善较为明显；基于多项式拟合的投影延拓处理可进一步提高超高海拔流动站对流层延迟量的求解精度。

英文摘要：

A projection-extension method to calculate zenith tropospheric delay （ZTD）of mobile stations was presented. The method is based on the inverse distance weighted fomular derived from Taylor series expansion, and the high order terms were considered. The interpolating accuracy can be improved with the method for the stations located at extremely high elevations. Operation of the method is to project elevation of a station to the mean eleva- tion plane, and to calculate the ZTD of the projection point with the method, then extend it to the actual position u- sing polynomial fitting. An experiment results is done with the GPS data of SCIGN, and the results show that the in- terpolation method based on higher Taylor series expansion has better performance in calculating ZTD of rover sta- tions than IDW, especially for stations with high elevations. Combined with projection-extension method,it can also get ZTD of rover stations which have extremely high elevation at millimeter-level accuracy.