An Improved Ionospheric Spatial Threat Model for SBAS  

作　　者：ZHANG Qidong LI Rui WANG Zhipeng 

机构地区：[1]School of Electronic and Information Engineering,Beihang University,Beijing 100191,China

出　　处：《Chinese Journal of Electronics》2017年第5期1105-1110,共6页电子学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.61501010,No.U1433114,No.61501014,No.61521091);Aeronautics Science Foundation(No.2015ZC51035)

摘　　要：A conservative Grid ionospheric vertical delay error(GIVE) estimation would lead to conservative Protection levels(PLs) estimation and affects Satellitebased augmentation systems(SBAS) service performance.To reduce the margin in GIVE estimation,an improved spatial threat model is presented.A new parameter of Minimum separation distance(MSD) is introduced.The new model is described with the MSD,Relative centroid metric(RCM) and fit radius as inputs.Ionospheric delay measurements during storms are used to construct the new spatial threat model.Simulation results show that,with the new model,there is at least 9.5% reduction in User ionospheric vertical delay errors(UIVEs),while the user ionospheric delay estimation errors can be bounded at the same time.Even on severe ionosphere disturbed days,at least 5% improvement of PLs(95%) could be achieved for more than20% Conterminous united states(CONUS) area,leading to higher system service performance.A conservative Grid ionospheric vertical delay error（GIVE） estimation would lead to conservative Protection levels（PLs） estimation and affects Satellitebased augmentation systems（SBAS） service performance.To reduce the margin in GIVE estimation,an improved spatial threat model is presented.A new parameter of Minimum separation distance（MSD） is introduced.The new model is described with the MSD,Relative centroid metric（RCM） and fit radius as inputs.Ionospheric delay measurements during storms are used to construct the new spatial threat model.Simulation results show that,with the new model,there is at least 9.5% reduction in User ionospheric vertical delay errors（UIVEs）,while the user ionospheric delay estimation errors can be bounded at the same time.Even on severe ionosphere disturbed days,at least 5% improvement of PLs（95%） could be achieved for more than20% Conterminous united states（CONUS） area,leading to higher system service performance.

关 键 词：Spatial threat model Grid ionospheric vertical delay error(GIVE) Minimum separation distance 

分 类 号：P352[天文地球—空间物理学] TN967.1[天文地球—地球物理学]