北斗星基增强电离层模型精度评估与分析

Accuracy Evaluation and Analysis for BDSBAS Ionosphere Model

针对如何有效地对北斗星基增强系统(SBAS)电离层在模型精度、模型时效性等方面进行综合评估,提出了一种修正的CODE格网模型,通过增加国内陆态网监测站观测数据,提升了CODE格网模型精度。以此模型为基准,利用2020年近一个月的数据分析了北斗区域格网电离层模型和北斗SBAS电离层模型的延迟误差、改正比例的变化以及在全球的覆盖范围,并从全球不同纬度带比较了北斗基本导航和星基增强电离层模型的精度。结果表明修正的CODE模型精度符合评估要求,且与我国电离层实际变化情况更吻合,北斗区域格网电离层模型和北斗SBAS电离层模型精度相当,优于0.3m,改正比例均优于80%,但北斗SBAS电离层模型覆盖范围明显更大。

Aiming at how to assess the Beidou satellite-based augmentation system(SBAS)ionospheric models in model accuracy,model timeliness and other aspects totally and effectively,this paper proposes a new method that evaluating the accuracy of Beidou SBAS ionosphere model based on the improved CODE model.The precision of CODE grid model can be improved by increasing the data of crustal movement observation network of China stations in China.Based on this model,the delay error,the change of correction ratio and the global coverage of Beidou regional grid ionospheric model and Beidou SBAS ionospheric model are analyzed by using the data of nearly one month in 2020,and the accuracies of Beidou ionospheric models from different global latitudes are analyzed.The results show that the accuracy of the modified code model meets the evaluation requirements,and is more consistent with the actual ionospheric changes in China,Beidou regional grid ionosphere model and Beidou SBAS ionosphere model have the same accuracythat is better than 0.3m,and the correction ratios are more than 80%;the coverage of the Beidou SBAS ionosphere model is significantly larger.