TY - JOUR A1 - Tu, Rui A1 - Zhang, Hongping A1 - Ge, Maorong A1 - Huang, Guanwen T1 - A real-time ionospheric model based on GNSS Precise Point Positioning JF - Advances in space research N2 - This paper proposes a method of real-time monitoring and modeling the ionospheric Total Electron Content (TEC) by Precise Point Positioning (PPP). Firstly, the ionospheric TEC and receiver's Differential Code Biases (DCB) are estimated with the undifferenced raw observation in real-time, then the ionospheric TEC model is established based on the Single Layer Model (SLM) assumption and the recovered ionospheric TEC. In this study, phase observations with high precision are directly used instead of phase smoothed code observations. In addition, the DCB estimation is separated from the establishment of the ionospheric model which will limit the impacts of the SLM assumption impacts. The ionospheric model is established at every epoch for real time application. The method is validated with three different GNSS networks on a local, regional, and global basis. The results show that the method is feasible and effective, the real-time ionosphere and DCB results are very consistent with the IGS final products, with a bias of 1-2 TECU and 0.4 ns respectively. KW - Ionospheric monitoring and modeling KW - Precise Point Positioning (PPP) KW - Real time KW - Total Electron Content (TEC) KW - Global Navigation Satellite System (GNSS) KW - Differential Code Biases (DCB) Y1 - 2013 U6 - https://doi.org/10.1016/j.asr.2013.06.015 SN - 0273-1177 SN - 1879-1948 VL - 52 IS - 6 SP - 1125 EP - 1134 PB - Elsevier CY - Oxford ER -