顾及电离层延迟改正精度信息的伪距单点定位随机模型

A stochastic model for pseudorange single point positioning with consideration of the accuracy of ionospheric delay correction

关键词:  伪距单点定位  广播电离层模型  随机模型  电离层延迟改正

Key words:  Pseudorange single point positioning  Broadcast ionospheric model  Stochastic model  Ionospheric delay correction

摘要:

针对太阳活动高年电离层活跃期卫星导航信号受电离层扰动影响导致伪距单点定位精度下降的问题，提出了一种在传统高度角定权外额外顾及电离层延迟改正精度信息对观测值权的影响的随机模型。分析了北斗卫星导航系统（BDS）和全球定位系统（GPS）在采用北斗全球广播电离层模型（BDGIM）和Klobuchar广播电离层模型时不同随机模型的伪距单点定位精度，并与电离层平静期的结果进行对比。实验结果表明，在电离层活跃期顾及电离层延迟改正精度的随机模型的定位精度相比高度角定权模型有较大提升，采用BDGIM时使用顾及电离层延迟改正精度的随机模型，将BDS,GPS及GPS+BDS+Galileo的平均定位精度分别提升了6.63%，4.73%和6.37%，而采用Klobuchar广播电离层模型时，将平均定位精度分别提升了7.41%，7.15%和6.38%；在电离层平静期，顾及电离层延迟改正精度的各随机模型相比高度角定权模型定位精度提升低于电离层活跃期。

Abstract:

In response to the problem of reduced accuracy in pseudorange single point positioning due to ionospheric disturbances during periods of high solar activity, a stochastic model is proposed， which considers the effect of ionospheric delay correction accuracy on the weighting of observations in addition to the traditional elevation angle weighting. The accuracy of peudorange single point positioning for the BeiDou satellite navigation system (BDS) and the global positioning system (GPS) is analyzed using the BeiDou global ionospheric model (BDGIM) and the Klobuchar broadcast ionospheric model with different stochastic models, and the results are compared with those in ionospheric quiet periods. The experimental results show that during the ionospheric active period, the positioning accuracy of the stochastic model that considers the precision of the ionospheric delay correction is significantly improved compared to the elevation angle weighting model. Among the different stochastic models, the average positioning accuracy improvements for BDS, GPS and GPS+BDS+Galileo are 6.63%, 4.73% and 6.37% respectively when using BDGIM considering the precision of the ionospheric delay, and 7.41%, 7.15% and 6.38% respectively when using Klobuchar broadcast ionospheric model. During the ionospheric quiet period, the improvement in positioning accuracy of the stochastic models considering ionospheric delay correction precision is less pronounced than that in the ionospheric active period.