Rapid Re-Convergence of Real-Time Dynamic Precise Point Positioning by Adding Velocity Constraints

• Published in: Gyroscopy and navigation (Online) Vol. 13; no. 4; pp. 283 - 293
• Main Authors: Xingxing Wang, Sheng, Chuanzhen, Yu, Baoguo, Zhang, Ziteng, Zhang, Jingkui, Yi, Qingwu
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2022; Springer Nature B.V
• Subjects: Accuracy; Aerospace Technology and Astronautics; Constraint modelling; Convergence; Doppler sonar; Dynamic models; Dynamic positioning; Engineering; Geological hazards; Geophysics/Geodesy; Global navigation satellite system; Global positioning systems; GPS; Kinematics; Navigation; Real time; Satellites; Velocity; dynamic precise point positioning; velocity constraints; re-convergence; real-time; signal blocking
• ISSN: 2075-1087; 2075-1109
• DOI: 10.1134/S2075108722040125

— In challenging environments like urban vehicle navigation and geological hazards, the GNSS signals are easily blocked, and the long re-convergence time seriously limits many applications of real-time dynamic precise point positioning. Considering that the velocity accuracy is better than the position during re-convergence epochs, we proposed a real-time rapid-positioning method by introducing velocity constraints into the dynamic PPP. According to the different motion states and environments, different velocity constraints are used adaptively. For example, the zero-velocity constraint model is used in the stationary state; the Doppler-velocity constraint model is used when the most visible satellites are temporarily blocked; the other-sensors-velocity constraint model is used when the satellite signal is blocked frequently. Considering that the inaccurate dynamic model will affect the dynamic positioning results, the velocity constraint can be gradually relaxed after the GNSS signals are reacquired and the ambiguity gradually converges. Based on static and kinematic experiments with GPS data, the results show that when the number of visible satellites is greatly dropped due to signal blocking, the new positioning method can significantly speed up the re-convergence of precise point positioning, maintain high accuracy and improve the continuity of real-time dynamic positioning in a short time.