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

  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.