An improved regional ionospheric model for single-frequency GNSS users

In this study, we develop a regional ionospheric model for single-frequency precise point positioning (PPP) users in Europe. GNSS observations from 60 IGS and EUREF reference stations are processed using the PPP module in the Bernese software to estimate the vertical total electron contents. The developed model has spatial and temporal resolutions of 1 degrees x 1 degrees and 15 minutes, respectively. The resulting model is validated for PPP applications using GNSS observations from another set of stations in three different days. The single-frequency PPP accuracy and convergence time obtained through the developed model are assessed and compared with those obtained through the international GNSS service global ionospheric maps (IGS-GIM). The dual-frequency ionosphere-free PPP is used as a reference. It is shown that the model improves the PPP accuracy and convergence time by about 20, 45 and 45% for the 2D, height and 3D components, respectively, in comparison with the IGS-GIM model.