利用长期观测资料评价GPS短基线的定位精度

Evaluating the Precision of GPS Positioning for Short Baseline Using Long-term Data

根据隔河岩大坝外观变形ＧＰＳ自动化监测系统的大量观测资料（１９９８年６月－１９９９年１２月），全面分析并评价了间距为１ｋｍ的两个工作基点相对定位的三维精度。结果表明，２小时解的精度为∧±２．８６ｍｍ（ｎ）、±２．５０ｍｍ（Ｅ）和±６．５２ｍｍ（Ｕ）；６小时解的精度为±２．０６ｍｍ（Ｎ）、±１．７７ｍｍ（Ｅ）和±４．４９ｍｍ（Ｕ）；垂直方向的精度约水平方向的２．５倍。这一精度分析结果具有大子样容量的特性．客观反映了ＧＰＳ在单一短基线进行相对定位的三维精度情况，可为ＧＰＳ用于精密工程测量和变形监测的方案设计提供参考。

On the basis of a vast amount of GPS data (from June 1998 to December 1999) collected from GPS automatic monitoring system of outside deformation for Geheyan Dam, in this paper the 3- dimentional relative positioning precision for tow working datum marks about lkm long of this system was analyzed and evaluated. Results showed that the precision of 2h solutions was ±2.86 mm(NS direc- tion) ±2.50 mm(EW direction) and ±6.52 mm(U direction), that of 6h solutions was ±2.06 mm(NS direction)±1.77 mm(EW direction) and ±4.49 mm(U direction), and the precision in vertical compo- nent was about 2.5 times greater than in horizontal directions. The statistic analysis results had the char- acteristic oflarge Sample quantity, reflected veriy the 3-dimentional relative positioning precision for a single short baseline, and provided reference data for the design of GPS used for precise engineering sur- veying and deformation monitoring.