Impact and synergies of GIM error estimates on the VTEC interpolation and single-frequency PPP at low latitude region

Abstract The vertical total electron content (VTEC) is one of the key quantities to describe variations ionosphere and can be provided users correct ionospheric disturbances for GNSS (Global Navigation Satellite System) positioning. VTEC values corresponding standard deviations are routinely in so-called Global Ionosphere Maps (GIM), with a typical time resolution 2 h (and up 15 min) on regular grids 2.5º latitude 5º longitude. To determine corrections from GIMs positioning applications, an interpolation has applied grid values, which generally degenerates final accuracy. In this context, typically bi-linear calculated by introducing new weighting scheme means deviation maps domain. sequel, impact use uncertainties procedure different centers assessed For assessment GIM domain, compared directly obtained given GIM, i.e., without interpolation. analyzed single-frequency precise point (PPP), considering four Brazilian stations challenging regions. provides significant improvement periods high solar flux, especially region under more intense effect (mean rates improvements 47%).