Local Models for Ionospheric VTEC Estimation Based on GR Models with Multi-Layer Model

In this paper, the multi-layer ionospheric model based regional VTEC estimation methods applied by GNSS Regressive models (abbreviated as GR models) [1]-[6] are presented. In the methods, the spherical cap harmonic analysis (SCHA) as well as the spherical harmonic functions (SHF) are also applied to model the regional VTEC distributions. The ionospheric delays (or advances) over Japan estimated by using Gps Earth Observation NETwork (GEONET) data provided from the Geographical Survey Institute (GSI) of Japan are also shown [7].