Performance analysis of ionospheric enhanced PPP-RTK in different latitudes

摘要: Objectives Slow convergence has always been an important factor of limiting the development of precise point positioning (PPP). Studies have shown that the convergence speed of PPP can be significantly improved with high-precision ionospheric delay correction, and then to achieve PPP-real time kinematic (PPP-RTK). At present, the ionosphere in the regional PPP-RTK mainly adopts the satellite-based ionospheric model with polynomial function (SIM_POLY) and the satellite-based ionospheric model with inverse distance weight function (SIM_IDW) for construction.Methods In order to verify the modeling accuracy of the above two models at different latitudes, this paper first used the observation data of Guangdong, Hubei and Hebei provinces to establish ionospheric delay models, and then applied the above models to float and fixed solutions PPP under single GPS and GPS+ BDS systems. Finally the results were compared with IFPPP (ionosphere-free PPP) and CODE GIM (Centre for Orbit Determination in Europe Global Ionospheric Map, CODG) correction.Results Experimental results showed that in the low-latitude provinces, SIM_IDW model slightly outperformed SIM_POLY model, but there was no significant difference in the middle and high latitude provinces. Compared with IFPPP and CODG correction, PPP under SIM_IDW and SIM_POLY correction has a better performance. Besides, Hebei province achieved the fastest convergence speed compared with Guangdong and Hubei provinces, and compared with IFPPP, the positioning accuracy in single GPS solution under SIM_IDW and SIM_POLY model correction is improved by 43 …