Satellite laser ranging station classification for GNSS satellite orbit accuracy validation

GNSS satellite orbit is the basis of the realization of navigation, positioning and other location services. The precision of satellite orbit accuracy evaluation is related to the accuracy and reliability of services. Satellite laser ranging technology is a reliable external check method to evaluate the satellite orbit accuracy. Due to the different level of SLR station system, the data quality is greatly different. The reasonable selection of high performance SLR station is the key to accurately evaluate the satellite orbit. In this study, based on the performance evaluation report of global SLR stations published by the International Laser Network in the last 10 years, three parameters including total number of observations, LAGEOS standard point RMS value and system short-term deviation are selected as the evaluation indexes to grade the global SLR stations. On this basis, the precision of all GNSS satellites participating in the international Laser joint survey in 2020 is checked. The results show that the level of SLR stations is closely related to the data quality. The fuzzy C-means clustering algorithm can effectively classify the global SLR stations, and the proportion of class I, class II and class HI stations is 28%, 51% and 21 %, respectively. There exist significant differences among the GNSS satellite orbit accuracy obtained by using SLR data of different class stations. The mean absolute value and standard deviation of residual based on class I station are generally smaller than that of class II and class HI stations. According to the GLONASS, BDS and Galileo satellite orbits residuals checked by class I station data, the statistical analysis of the residual components in the RTN coordinate system shows that the difference of the three GNSS satellites' orbit accuracy in all directions is not obvious, and the difference between the RMS values of the corresponding components is at mm level. © 2023 SinoMaps Press. All rights reserved.