Rapid centimeter-level positioning based on BeiDou-3 global short message communication

Ambiguity resolution (AR) is an effective way to improve the solution accuracy and convergence speed of precise point positioning (PPP), with the help of real-time precise orbit, clock and uncalibrated phase delay (UPD) products acquired by the internet from analysis centers (ACs) of the international global navigation satellite system (GNSS) service (IGS). To address the problem regarding the inability to access real-time products in regions lacking internet service, we proposed optimized strategies for observation space representation (OSR) corrections encoding, broadcasting and estimating to achieve real-time PPP-AR based on the global short message communication (GSMC) of the BeiDou navigation satellite system (BDS-3). Due to the limited bandwidth of the BDS-3 GSMC, the corresponding encoding strategy is rationally designed for UPD products, on the basis of analyzing the numerical distributions for them. In addition, broadcasting strategies have been developed based on the 1 min service frequency of the BDS-3 GSMC. With the OSR corrections being encoded and recovered based on Wuhan University's ((WHU's) real-time orbit and clock products, the performance of real-time PPP-AR is implemented and evaluated. The kinematic experiments show that centimeter level positioning accuracy can be achieved after about 13.1 min of convergence at the 68% confidence level and over 92% of arcs have converged within 30 min. When a communication delay of 20 s is introduced, the convergence time increases to 15.4 min, with approximately 91% of the arcs achieving successful convergence.