电离层不均匀性对GPS系统的误差影响分析

在ＧＰＳ定位误差分析中，对电离层误差大多只考虑了折射效应，采用双频技术即可消除折射一阶项的影响，更进一步的误差分析通常是考虑电离层折射的高阶项（主要是二阶项）。但均未考虑电离层不均匀性对ＧＰＳ系统误差的影响。本文根据波在电离层随机介质脉冲平均到达时间的理论结果，对ＧＰＳ信号穿越电离层的情况进行了模拟计算，在得出了典型背景电离层参数条件下折射一阶项、二阶项引起的ＧＰＳ信号延迟误差的基础上，重点讨论了

The Effects of Ionospheric Irregularites on GPS Signal Delay

In the study of GPS measurement error, the ionospheric refractive effect was only taken into account. The error of first order refractive effect can be corrected by using dual-frequency GPS receiver. Second order refractive effect was taken into account when high precision measurement was required. But the scattering effect of ionospheric irregularities has not yet been taken account.Based on the results of mean arrival time of pulse signal propagating through random medium, simulation of GPS signal propagating through ionosphere wsas done in this paper. With a specifed background ionosphere and ionospheric irregularity, emphasis were given to the scattering effect with comparing to the first order and second order refractive effect on GPS signal delay. It shows that the scattering effect of irregularities is important with respect to the refractive effect of the background ionosphere in certain case.