电离层延迟高阶项对GPS精密单点定位精度影响分析

An Influence Analysis of High-order Ionosphere on GPS Precise Point Positioning

随着GPS卫星轨道、钟差及各种误差修正模型的不断精化,静态精密单点定位(PPP)定位精度达到mm级,进行电离层延迟高阶项较小量级的误差改正研究,对改进PPP数据处理策略具有重要的参考价值。本文利用分布在不同地理纬度的5个IGS跟踪站3天的观测数据,对比分析了电离层延迟二阶项、三阶项对GPS观测值精度及静态PPP定位精度的影响。分析结果表明,电离层延迟二阶项、三阶项对GPS观测值精度的影响分别为cm级和mm级,对低纬度地区PPP定位精度的影响大于3mm,但对中高纬度的测站观测值、定位精度的影响比低纬度地区小很多。

With the continuous refinement of GPS satellite orbit,clock error and various error correction models,carrying out the study on the high-order ionospheric error correction of static Precision Point Position(PPP),which has an important reference value for improving the processing strategy of PPP observations.The influence degree of high-order ionospheric error on the accuracy of GPS observations and static PPP is analyzed and compared,using the observations from 5 IGS tracking stations,during January 7-9,2013.The results show that:1)the influence of the second-order and the third-order of the ionospheric error on the accuracy of GPS observation are cm level and mm level,respectively;2)the influence of the high-order ionospheric error on the accuracy of GPS PPP is more than 3 mm in low latitude.But the influence degree on the accuracy of the observations and PPP in middle and high latitudes is much smaller than that in low latitudes.