Estimating the Ionospheric Delay Using GPS/Galileo Signals in the E5 Band

Abstract — The estimation of the ionospheric delay by a GNSS receiver is quite simple when the receiver has access to signals located at different frequencies. However, when these two frequencies are very close, this estimation process becomes very noisy. The paper presents a technique to overcome this problem in the case of the reception of Galileo signals in the E5 band only. This technique is based on a local ionosphere model and the use of carrier phase dual frequency measurements. This paper also widen this investigation to the case of the reception of two GNSS constellations, GPS and Galileo, broadcasting in the same E5 band. The performance of the estimation process are shown to be very good in Europe with a standard deviation of the estimation error at L1 that is below 30cm for the worst case ionosphere conditions. Keywords—GNSS, Ionosphere estimation, Galileo, GPS I