电离层不规则结构对GPS性能的影响

Effect of Ionospheric Irregularities on GPS Performance

电离层不规则结构的存在可引起无线电信号的幅度和相位发生随机起伏,这种电离层闪烁现象会影响全球定位系统(Global Positioning System,GPS)的性能,降低定位精度,严重时导致信号失锁.电离层不规则结构对GPS性能的影响涉及电离层物理、接收机设计和表征卫星几何分布的精度衰减因子(Dilution of Positioning,DOP)等多方面因素.本文通过对表征电离层不规则结构参数的分析,根据GPS接收机跟踪环路和闪烁信号模型,综合研究了电离层闪烁对GPS接收机载波跟踪环和码跟踪环跟踪误差的影响;结合实际观测,评述了电离层不规则结构对单频和双频GPS接收机定位性能的影响,在此基础上提出了有待深入研究的问题及具体建议.

Ionospheric irregularities may cause the amplitude and phase fluctuation of the trans- ionospheric radio signals, known as ionospheric scintillation. It can increase the tracking error of Global Positioning System （GPS） receiver, degrade the positioning accuracy and precision, and even cause loss of lock. This paper is a review of the effect of ionospheric irregularities on GPS receiver＇s performance. First, the parameters used to describe the ionospheric irregularities and the GPS receiver tracking loops are introduced. Based on the scintillation signal model, the results on how the ionospheric scintillation affects the performances of carrier and code tracking loops are summarized. Then the positioning errors of single frequency and dual-frequency GPS receivers are analyzed and discussed under realistic ionospheric scintillation environments. Finally, possible suggestions to future research topics are given.