Abstract
Precision point positioning (PPP) is widely used in maritime navigation and other scenarios because it does not require a reference station. In PPP, the satellite clock bias (SCB) cannot be eliminated by differential, thus leading to an increase in positioning error. The prediction accuracy of SCB has become one of the key factors restricting positioning accuracy. Although International GNSS Service (IGS) provides the ultra-rapid ephemeris prediction part (IGU-P), its quality and real-time performance can not meet the practical application. In order to improve the accuracy of PPP, this paper proposes to use the Prophet model to predict SCB. Specifically, SCB sequence is read from the observation part in the ultra-rapid ephemeris (IGU-O) released by IGS. Next, the SCB sequence between adjacent epochs are subtracted to obtain the corresponding SCB single difference sequence. Then using the Prophet model to predict SCB single difference sequence. Finally, the prediction result is substituted into the PPP positioning observation equation to obtain the positioning result. This paper uses the final ephemeris (IGF) published by IGS as a benchmark and compares the experimental results with IGU-P. For the selected four satellites, compared with the results of the IGU-P, the accuracy of SCB prediction of the model in this paper is improved by about 50.3%, 61.7%, 60.4%, and 48.8%. In terms of PPP positioning results, we use Real-time kinematic (RTK) measurements as a benchmark in this paper. Positioning accuracy has increased by 26%, 35%, and 19% in the N, E, and U directions, respectively. The results show that the Prophet model can improve the performance of PPP.
Highlights
Since the beginning of the 21st century, location-based service applications had become more widespread
High precision and continuity provide the basis for high-precision navigation and positioning for GNSS users [19]
Read the observation data and ephemeris data provided by the International GNSS Service (IGS) station, and store these data in a certain format, which is convenient for subsequent programs to call the data
Summary
Since the beginning of the 21st century, location-based service applications had become more widespread. With the continuous development of RTK, the positioning accuracy of GNSS has reached centimeter level [1]. This makes automated vehicles (AVs) more and more realistic [2]. Positioning accuracy determines the level of development of autonomous vehicles. There are many problems with the practical application of RTK. An effective reference station cannot be established in the wild and the vast sea area. The positioning accuracy will decrease rapidly with the increase of the baseline length [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
