Abstract:To solve the problem of the slow convergence speed of the existing single-system, GPS PPP, we select the LEO constellation system composed of different numbers of satellites. According to the observational value simulation principle, we obtain the pseudorange observations and phase observations of the points to be estimated from low-orbit satellites. To analyze the enhancement effect of LEO constellation, we select CPVG, WUH2, KOUG, IISC, FUCN stations, and use GPS and LEO constellation observation data with additional orbital error to perform static precise single-point positioning. The results show that: 1) After adding the LEO constellation to the original GPS system, the average number of visible satellites increased by 9.7, 19.4 and 31.3, and the PDOP value decreased by 0.7, 0.9 and 1.1, respectively; 2) The convergence time was shortened rapidly, the single system of GPS satellites were reduced from 17.1 min to 4.7 min, 2.1 min, and 1.5 min, respectively, and the convergence time was shortened by 67.3%, 84.4%, and 89.5%, respectively; 3) The RMS value in the N direction was increased by 37.4%, 60.3%, and 67.3%, respectively, the E direction increased by 34.4%, 59.4%, and 72.9%, respectively, and the U direction increased by 55.9%, 71.7%, and 79.6%. LEO constellation greatly improves the performance of GPS PPP, which is of great significance for guiding the design of LEO constellation enhanced GPS system and the expansion of application scenarios for precise single-point positioning.
YUE Hengyi,LI Kai,HU Xiaogong et al. Combined GPS/LEO PPP: Considering the Number of Different Satellites and Orbit Errors[J]. jgg, 2022, 42(11): 1117-1121.