Regional real-time GNSS satellite clock error estimation and real-time PPP service application

The regional global navigation satellite system (GNSS) real-time high-precision satellite clock error estimation is crucial for delivering accurate regional precise point positioning (PPP) services. To address challenges such as estimation accuracy, time consumption, uneven distribution of stations, and network latency in regional networks, which compromise the timeliness and accuracy of real-time satellite clock error services, an improved method for real-time clock error estimation and service is proposed. This method employs a satellite clock error model that utilizes polynomial and harmonic-based functions. It directly estimates the model coefficients using phase and pseudorange observation data from a regional GNSS network. PPP users can use these coefficients to derive satellite clock errors at any given time. The proposed method streamlines the process of real-time clock error estimation and service, potentially increasing service availability for GPS and BDS-3 by up to 16.1% and 21.3%, respectively. The clock error accuracy estimated by the proposed method is comparable to that of the single-epoch estimation method, while enabling PPP users to access 1-3 additional satellites clock error service. Experimental results demonstrate that the proposed clock error estimation method enhances the accuracy of both static and kinematic PPP, with a maximum improvement of approximately 33.3%. Additionally, it reduces positioning convergence time to varying degrees, with the most significant reduction being about 4.9 min. Overall, the proposed method not only improves the timeliness of real-time clock error services but also extends their availability. It proves to be both feasible and effective in enhancing positioning accuracy and accelerating convergence.