几种电离层模型对单频单点定位的影响分析

Effect Analysis of Several Types of Ionospheric Models on Single-frequency Single-point Positioning

针对实时GNSS单频定位中电离层延迟改正问题,本文采用可用于实时GNSS单频定位的几种电离层模型对电离层延迟进行改正并分析其对GNSS单频单点定位性能的影响。其中,对单频SPP的电离层延迟采用模型直接进行改正,采用Klobuchar模型、CODE的预报产品c1pg、原国家测绘地理信息局的实时球谐电离层产品cosong和CODE事后产品codg计算的电离层精度依次提高;采用不同电离层模型作为电离层估计的先验约束进行单频PPP定位。结果表明:采用精度较好的电离层产品作为先验约束可加快单频PPP收敛。

Aiming at the problem of ionospheric delay correction in real-time GNSS single-frequency positioning,several types of ionospheric models are used to correct the ionospheric delay,and their effects on the performance of GNSS single-frequency positioning are analyzed. As the ionospheric delay in single-frequency SPP is corrected directly by the models,the results show that the accuracy of ionospheric delay calculated by the Klobuchar model,the prediction product c1pg of CODE,the real-time spherical harmonic ionosphere product cosong of the National Geographic Information Bureau,and the after-product codg of CODE is improved sequentially.As different ionospheric models are used as the priori constraints of ionospheric estimation for single-frequency PPP positioning,is shows that the convergence of single-frequency PPP can be accelerated by using ionospheric products with better accuracy as a prior constraint.