Real-time ocean precise point positioning with BDS-3 service signal PPP-B2b

Abstract

For ocean high-precision positioning, the Real-Time Kinematic (RTK) technique exists disadvantages since the positioning accuracy will deteriorate with the baseline elongating. The real-time Precise Point Positioning (PPP) based on Real-Time Service (RTS) may be difficult to operate on ocean since the internet-based communication is unavailable. As an alternative, the PPP-B2b service provided by BeiDou Global Navigation Satellite System (BDS-3) is considered free from these limiting requirements, and it can realize real-time PPP for users in China and surrounding areas. This research focuses on a real-time PPP with BDS-3 service signal PPP‑B2b in ocean high-precision positioning application. The real-time satellite orbit and clock are recovered, and the accuracy are evaluated with collected 10-day PPP-B2b messages. The results indicate that the accuracy of PPP-B2b satellite orbit is better than 0.1 m in the radial component and the satellite clock offsets achieve an accuracy of better than 0.2 ns for both BDS-3 and Global Positioning System (GPS). The land simulated real-time kinematic PPP experiment using 7 International GNSS Service (IGS) stations observations yielded the three-dimensional (3D) positioning accuracy of 11.6 cm for BDS-3 only and 8.3 cm for GPS + BDS-3. Finally, an ocean real-time kinematic PPP positioning experiment is carried out and the data quality of ocean observations are analyzed. The ocean real-time PPP with PPP-B2b corrections achieves the 3D Root Mean Square (RMS) of 21.3 cm for BDS-3-only and 18.2 cm for GPS + BDS-3, which indicates that the PPP-B2b service provided by BDS-3 is prospective in location-based ocean application.