GNSS广播电离层模型精度评估

Accuracy Evaluation of GNSS Ionospheric Models

电离层延迟误差直接影响高精度定位。GPS、Galileo、BDS均向用户播发电离层修正模型参数。本文以欧洲定轨中心（CODE）的电离层格网数据为基准，对GPS、BDS、Galileo系统的电离层参数性能进行了评估。结果表明，三种模型在中国及其周边地区（70°E～145°E、5°N-60°N）的电离层改正率均在65％左右，我国北斗Klobuchar模型在中、低纬度地区的改正精度总体优于其他两种模型，但在较高纬度地区的改正效果还有待进一步提高；GPS的K8模型在高纬度地区的改正精度较高，而Galileo系统的修正精度变化幅度较小，估计精度适中。

The ionosphere delay error affects the high precision positioning. GPS, Galileo and BDS provide the ionospheric correction model parameter for the users. Based on the ionosphere grid data from CODE, the paper evaluates the performance of three ionosphere parameters for GPS, BDS and Galileo. The experiments show that the ionosphere correction percentage of the three models in China and its surrounding is about 65%. Besides, the correction accuracy of BDS Klobuchar model in low and mid - latitude regions is better than that of the other two models, however, the performance in high - latitude area needs to be im- proved. Moreover, GPS Klobuchar model has a relatively high correction precision in high -latitude area while NeQuick model of Galileo has smaller fluctuation and the correction accuracy is moderate.