全球实时电离层模型精度分析--以CAS、CNES、NRCan及UPC产品为例

Accuracy Analysis of Real-Time Global Ionospheric Maps from CAS,CNES,NRCan and UPC

分析中国科学院(CAS)、法国国家空间研究中心(CNES)、加拿大自然资源部大地测量局(NRCan)和加泰罗尼亚理工大学(UPC)2021-01~08的全球实时电离层格网(RT-GIM)产品的精度。结果表明:(1)以IGS事后全球电离层格网(GIM)为参考,CAS、CNES、NRCan和UPC产品的RMS分别为3.93 TECu、4.01 TECu、4.50 TECu和3.86 TECu;(2)以基准站dSTEC为参考,CAS、CNES、NRCan和UPC产品的STD分别为4.42 TECu、4.40 TECu、4.96 TECu和4.42 TECu。在全球范围内选取21个测站进行连续7 d的定位测试,以高程方向残差95%分位数统计不同实时电离层产品的定位增益。相比于广播电离层模型的定位结果,CAS、CNES、NRCan和UPC产品在北半球高程方向的定位精度分别提升11.9%、18.3%、3.4%和15.5%。

We analyze the accuracy of the RT-GIM products during January and August 2021 from Chinese Academy of Sciences(CAS),Centre National d’Etudes Spatiales(CNES),Canadian Geodetic Survey of Natural Resources Canada(NRCan)and Polytechnic University of Catalonia(UPC).Compared to the post-processed IGS-GIM,the RMS between those RT-GIM and the IGS-GIM is 3.93 TECu for CAS,4.01 TECu for CNES,4.50 TECu for NRCan and 3.86 TECu for UPC.Compared to the dSTEC derived from reference stations,the STD of RT-GIM from CAS,CNES,NRCan and UPC are 4.42 TECu,4.40 TECu,4.96 TECu and 4.42 TECu,respectively.Based on the positioning results carried on 21 globally distributed GNSS stations during 7 consecutive days,we analyze the 95%quantile of vertical residuals to check the positioning improvement of different RT-GIM.Compared to positioning results corrected by the broadcast ionospheric model,the positioning accuracy increases by 11.9%for CAS,18.3%for CNES,3.4%for NRCan and 15.5%for UPC in the elevation direction of the northern hemisphere.