地磁暴期间电离层扰动监测及GNSS定位性能分析

Ionospheric disturbance monitoring and GNSS positioning performance analysis during geomagnetic storms

为分析磁暴期间电离层扰动规律及GNSS定位性能变化,基于国际GNSS服务(International GNSS Service,IGS)全球观测数据及全球电离层图(global ionospheric map,GIM),对2018年8月26日地磁暴事件引发的北半球地区电离层总电子含量(total electron content,TEC)异常变化和GPS定位性能进行分析.结果表明:北半球TEC异常存在纬度差异,高纬地区响应快,低纬地区异常值变化大,达12 TECU;磁暴期间高纬地区观测数据周跳变化明显,周跳比数值与磁静日相比最大下降61.84%;磁暴期间所有测站数据完整率下降,高纬地区下降响应快,下降严重,达38.65%,研究区所有测站数据完整率下降出现在磁暴恢复相,数据质量与TEC异常变化规律较为一致;对GPS双频动态精密单点定位(precise point positioning,PPP)结果进行分析发现,磁暴期间高纬地区测站定位误差显著增大,水平和垂直方向均方根误差(root mean squared error,RMSE)增至约0.7 m及1.8 m.

To analyze the disturbance patterns in the ionosphere and the changes in GPS positioning performance during magnetic storms,based on the IGS(International GNSS Service)global observation data and the GIM(Global Ionospheric Map),we conducted an analysis of the abnormal variation of total electron content(TEC)in the Northern Hemisphere during the geomagnetic storm event on August 26,2018,as well as the GPS positioning performance.The results show that the TEC anomalies in the Northern Hemisphere exhibit latitude differences,with faster responses in higher latitude regions and larger variations in lower latitude regions,reaching up to 12 TECU(total electron content unit).During the magnetic storm,significant cycle slips were observed in the higher latitude regions,with a maximum decrease of 61.84%compared to magnetically quiet days.The data integrity of all stations decreased during the storm,with higher latitude regions experiencing a faster and more severe decline,reaching 38.65%.The decrease in data integrity of all stations occurred during the recovery phase of the storm.The data quality is consistent with the pattern of TEC anomalies.Analyzing the results of GPS dual-frequency dynamic precise point positioning(PPP),it was found that the positioning errors at higher latitude stations during the magnetic storm significantly increased,with horizontal and vertical root mean square errors reaching approximately 0.7 m and 1.8 m,respectively.