Characterization and Performance Assessment of BeiDou-2 and BeiDou-3 Satellite Group Delays

Abstract

Following GPS, GLONASS, and Galileo, the Chinese BeiDou-3 system (BDS-3) started to provide navigation services for worldwide users in late 2019. Other than the second-generation BeiDou-2 system (BDS-2), which is mainly composed of satellites in geostationary Earth orbits (GEOs) and inclined geosynchronous orbits (IGSOs), BDS-3 is also comprised of 24 medium Earth orbit (MEO) satellites in three orbital planes that provide a global coverage. As the youngest global navigation satellite system (GNSS), BDS-3 makes use of highly advanced signal modulations and offers open service signals on five different frequencies. Along with a favorable signal-in-space range error (Montenbruck et al., 2020), which matches or even exceeds that of GPS, BDS-3 recommends itself as a highly competitive navigation system for worldwide users.Other than GPS and Galileo, which refer the satellite clock offset information in their broadcast navigation data to an ionosphere-free dual-frequency signal combination, BDS-2 and BDS-3 provide satellite clock offsets for the B3 frequency. Except for the uncommon case of a B3 single-frequency user, satellite group delays