Performance of Real-Time Precise Point Positioning

Abstract

The IGS Real-time Pilot Project (IGS-RTPP) provides real-time precise orbits and clocks, which support real-time positioning for single stations over large areas using the Precise Point Positioning (PPP) technique. This paper investigates the impact of real-time orbits, network configuration, and analysis strategies on real-time PPP implementation and demonstrates the real-time PPP performance. One month of data from the IGS network is analyzed in a real-time simulation mode. Results reveal the following: (1) In clock estimation, differential approaches are much more efficient than the zero-differenced approach. (2) The precision of IGS Ultra rapid (IGU) orbits could meet the IGS-RTPP requirement for precise clock estimation and PPP positioning. (3) Considering efficiency and precision, a network with 50 stations is recommended for the IGS-RTPP. It is demonstrated that the real-time satellite clock precision is 0.1 ns supporting hourly static PPP with a mean precision of 2–3 cm in the North component and 3–4 cm in the other components. Kinematic PPP assessed with onboard GPS data collected from a buoy provided mean coordinate precision of 2.2, 4.2, 6.1 cm in the North, East and Up directions, compared to the RTK solutions.

Keywords:

• Wide-area positioning
• IGU
• IGS-RTPP
• PPP

Acknowledgements

This research is supported by 100 Talents Programme of The Chinese Academy of Sciences and the National Natural Science Foundation of China (NSFC) (No. 40974018). Acknowledgment goes to BKG for providing the open-source BNC software. Two anonymous reviewers and Associate Editor are thanked for their constructive review of this manuscript. The members of the IGS group at the GFZ are acknowledged as part of this work was carried out when the first author worked there. The figures were produced using the Generic Mapping Tools (Wessel and Smith 1998).