一种顾及权重的PDOP值计算方法

A Computing Method of Weighted PDOP

在卫星定位中,定位精度主要受两方面的影响:一是观测卫星的空间几何分布;二是等效测距误差。传统的PDOP值计算方法,仅考虑了观测卫星空间几何分布的影响,所得到的PDOP值并不能准确地反映定位精度。将先验单位权中误差和卫星高度角引入到PDOP值计算过程中,提出了一种顾及权重的PDOP值计算方法。利用GPS单系统、北斗单系统以及GPS/北斗组合系统的实测数据进行分析,结果表明新方法计算得到的PDOP值能够更准确地反映定位精度。

The positioning accuracy is affected mainly by two aspects in the satellite-positioning. One is visible sat-ellites’ geometry distribution. The other one is user equivalent range error （ UERE） . The traditional computing method of PDOP only takes the visible satellites’ geometry distribution into account, but neglects the impact of UERE. Therefore, the PDOP value obtained by the traditional computing method can not accurately reflect the po-sitioning accuracy. In this paper, the mean square error of unit weight and satellite elevation are introduced into the computation of PDOP. A computing method of weighted PDOP is proposed. The test results using the GPS-only, BDS-only, and GPS/BDS real data indicate that the PDOP value obtained by the new computing method can accu-rately reflect the positioning accuracy.