The benefit of Galileo E6 signals and their application in the real-time instantaneous decimeter-level precise point positioning with ambiguity resolution

With the development of commercial services in the European Union, the advanced designs of Galileo E6 signals can be freely offered to Global Navigation Satellite System (GNSS) users. However, only a few studies have analyzed the benefit of Galileo E6 signals, and their application in the real-time instantaneous precise point positioning (PPP) with ambiguity resolution (AR) has not been investigated. In this study, based on the triple-frequency ionosphere-free combination, the positioning performance of instantaneous decimeter-level PPP AR was assessed with real-time orbit, clock and phase biases provided by the Centre National d'Etudes Spatiales Navigation Team (CNES/NAV). Experimenting on the GPS/Galileo observations from the 42 globally distributed stations, the wide-lane (WL) ambiguity residuals within +/- 0.25 cycle for GPS L1/L2/L5, Galileo E1/E5a/E5b and E1/E5a/E6 frequency combinations were 92.54%, 90.72% and 96.48% with single-epoch data, respectively. When the WL ambiguities are fixed instantaneously, owing to the low combination noise of Galileo E1/E5a/E6, the positioning performance of instantaneous PPP AR with GPS/Galileo (E1/E5a/E6 used) outperforms that of GPS/Galileo (E1/E5a/E5b used). If the position dilution of precision is <1.5, the Root Mean Square (RMS) of GPS/Galileo (E1/ E5a/E6 used) for east, north and up components are 0.13 m, 0.13 m and 0.57 m, respectively, while those of GPS/Galileo (E1/E5a/ E5b used) are 0.17 m, 0.19 m and 0.62 m, respectively. Moreover, the WL ambiguity fixing rate of GPS/Galileo (E1/E5a/E6 used) is higher than that of GPS/Galileo (E1/E5a/E5b used), which shows an improvement of approximately 9% in the relatively low satellite elevation angles (20 degrees< elevation angle < 40 degrees). The results indicate that the Galileo E6 signal can bring a significant improvement in real-time instantaneous decimeter-level PPP AR. (C) 2022 COSPAR. Published by Elsevier B.V. All rights reserved.