Real-time modeling and analysis of ionosphere in the China region
Ionospheric delay is a major source of error in Global Navigation Satellite System(GNSS).To correct for ionospheric errors,some GNSS applications such as single-frequencyprecise point positioning(PPP)and un-differenced uncombined PPP rely on Global Ionosphere Map(GIM)products.However,the release time of currently available GIM products is delayed,making them unsuitable for real-time GNSS applications.To address this issue,this paper proposes a real-time VTEC modeling method based on Kalman filtering,and generates a real-time regional ionosphere map(RT-RIM)for China based on observational data from 116 continuously operating reference stations.In addition,due to the strong coupling relationship between pseudorange differential code bias(DCB)and ionospheric delay,this paper also estimates the DCB of BDS-2/3,GPS,and Galileo systems.Statistical analysis results show that the Vertical Total Electron Content(VTEC)output by the model is in good consistency with the final GIM product of Chinese Academy of Sciences(CAS),with the RMS of their differences less than 2 TECU.After projecting VTEC into Slant Total Electron Content(STEC),the RMS of the deviation from the PPP estimation results is between 0.2 m and 0.8 m.The RMS of the deviation of the satellite DCB output by the model from the CAS rapid products is less than 0.8 ns.All these results indicate that the model proposed in this paper has good accuracy and can finely describe the spatiotemporal changes of ionospheric VTEC in the China region.
万方数据
维普
