Estimation method of ionospheric TEC distribution from single frequency GPS measurements using a slant effect model

Observational networks of GNSS signals are an important tool to observe ionospheric TEC distributions. These TEC observations are generally realized by measuring two frequency signals. Costs of multi-frequency receivers are, however, much higher than those of single frequency receivers. In the present study, we developed an estimation method of ionospheric TEC distribution from single frequency GPS measurements. In this method, the TEC distributions is assumed to be represented by a first-order gradient model whose parameters are estimated by a non-linear fitting. We confirmed the validity of the method by comparing results with TEC maps derived from GEONET data. This method can make it possible to build observational systems of ionospheric TEC in low latitude regions at low cost.