Abstract
In this paper, the multi-layer ionospheric model based regional VTEC (Vartical Total Electron Content) estimation methods applied by GNSS (Global Navigation Satellite System) Regressive models (abbreviated as GR models) are presented. In the methods, the SCHA (Spherical Cap Harmonic Analysis) as well as the SHF (spherical harmonic functions) are also applied to model the regional VTEC distributions. The ionospheric delays (or advances) over Japan are estimated by using GEONET (Gps Earth Observation NETwork) data provided from the GSI (Geospatial Information Authority of Japan). By applying the ionospheric correction based on the multi-layer model, the positioning accuracy can be improved, and consequently the regional ionosphere can be modeled more accurately by the multi-layer model.
