Real-Time Precise Point Positioning Using BeiDou

Satellite positioning is evolving rapidly, with the deployment of Galileo and BeiDou systems, in addition to the modernisation programmes for GPS and GLONASS. At the time of writing, the BeiDou constellation consists of 5 Geostationary Orbit (GEO), 5 Geosynchronous Orbit (IGSO) and 4 Medium-Earth Orbit (MEO) satellites. The constellation design is particularly interesting as it allows visibility of a sufficient number of BeiDou satellites over Asia for autonomous positioning. In this paper, possibilities for real-time precise point positioning (PPP) using BeiDou are explored. For real-time generation of orbit and clock products, observation data from Fugro's proprietary station network are used, together with data from the IGS Multi-GNSS Experiment (MGEX). In order to perform orbit estimation, the NAPEOS (Navigation Package for Earth Orbiting Satellites) software has been extended for processing BeiDou data. Satellite orbits are generated every hour and include a predicted part which can be used for real-time positioning. In order to estimate the accuracy of the real-time orbit, a validation with post-processed products is presented. A Kalman filter has been extended to process BeiDou observation data, in order to estimate satellite clock biases in real-time. For precise point positioning, Fugro's kinematic PPP engine is used. The engine is fed with real-time orbits and clocks, as well as observation data from test receivers. Kinematic PPP results are presented, in real-time and post-processing, including BeiDou standalone and in combination with GPS.