Accurate reference ionospheric model for testing GNSS ionospheric correction in EGNOS and Galileo

This work presents a procedure to assess ionospheric models tailored for Global Navigation Satellite System (GNSS) applications. The test is based on actual carrier-phase measurements. Using this strategy, the accuracy of the ionospheric broadcast models for Global Positioning System (GPS), Galileo and the European Geostationary Navigation Overlay System (EGNOS) is assessed. These models are compared to the Global Ionospheric Maps (GIMs) from the International GNSS Service (IGS) and a new product developed by the Research group of Astronomy and Geomatics (gAGE/UPC). The accuracies of the different ionospheric estimates are shown to affect the satellite and receiver Differential Code Bias (DCB) estimations. An accurate enough ionospheric modelling is shown to be able to detect actual drifts occurring in permanent receivers.