地基GNSS全球电离层延迟建模

Modeling Global Ionospheric Delay with IGS Ground-based GNSS Observations

海量地基GPS双频观测为电离层延迟建模提供了高分辨率时空覆盖的数据源。尽管如此,穿刺点的数量及空间分布、观测精度影响着建模精度。GLONASS/GPS兼容接收机增加了可观测的卫星数,改善了穿刺点的几何分布。基于此,完整地给出了GLONASS/GPS联合全球电离层延迟建模的算法实现以及数据处理策略。实测数据表明,在当前IGS站网分布下,GLONASS数据改善了全球电离层延迟模型化效果;卫星的DCB稳定性优于接收机的DCB,但GLONASS卫星DCB稳定性差于GPS卫星。

Mass ground-based GNSS dual-frequency observations provide a large quantity of data with high temporal and spatial resolution for ionospheric delay modeling.However,the number and the spatial distribution of ionospheric pierce point around the world,and the precision of the dual-frequency observations have great influence on the modeling of the Ionospheric delay.GLONASS/GPS compatible receivers adopted by the IGS stations increase number of available satellites and improve the geometric distribution of IPPs.In view of this advantage,this article mainly focus on combining GPS/GLONASS observations to establish global ionosphere delay model.Data analysis indicates that： ① GLONASS improve global ionospheric mapping under current IGS network.② DCB of GNSS satellites is more stable than those of receivers’,DCB of GLONASS satellites is not so good as DCB of GPS.③ There is bigger difference in south hemisphere between WHU and CODE GIM than that of north hemisphere.