关键词: 北斗卫星导航系统, 性能分析, 信号质量, 观测噪声, 精密单点定位, 基线解算, RTK定位

Abstract:

China's BeiDou navigation satellite system (BDS) has completed its global constellation establishment and began to provide positioning, navigation, and timing (PNT) services to global users. Based on the early principle of multi-system compatibility and interoperability, in the current market all the mainstream GNSS receivers support multi-system satellite signal reception. In order to improve the autonomy and security of the BDS PNT services, the government departments have issued opinions on accelerating the research, development and promotion, utilization of homemade standalone BDS positioning terminals. Since the standalone BDS receiver can no longer rely on the guidance of other system's signals during signal acquisition, its hardware and positioning performance may be changed, thus it is urgent to evaluate the navigation and positioning performance of the homemade standalone BDS receiver. In this paper, the M300 Pro standalone BDS receiver is selected to carry out a series of test and evaluation experiments, and the hardware performance of the receiver such as time to first fix (TTFF), signal quality and observation noise are evaluated first. Then the positioning performance such as station coordinate estimation, single point positioning (SPP), precise point positioning (PPP), static baseline solution and real-time kinematic (RTK) positioning are analyzed and discussed by using the self-developed BDS precise data processing software platform named space Geodetic spatio-temporal data analysis and research software (GSTAR). The experimental results show that the cold TTFF of the selected standalone BDS receiver is lower than 40 s, the average ratio of the intact observation data is more than 95%, and standard deviations of pseudorange and carrier phase measurement noise are 0.051 7 m and 0.003 4 cycles, respectively, which is basically consistent with the hardware performance of multi-GNSS receivers at home and abroad. Using the selected standalone BDS receiver, the single-day solution precision of the horizontal directions of station coordinates is 3.5 mm and the up direction is 9.9 mm; the precision of 2.208 m in horizon and 2.502 m in vertical can be realized with single-epoch pseudorange SPP; the precision of horizontal directions of kinematic PPP with ambiguity resolution (PPP-AR) is better than 3 cm and the up direction is better than 5 cm; the convergence time of the PPP-AR is better than 27 min; the repeatability accuracy of single-day solution for baselines shorter than 20 km is better than 0.7 cm in the horizontal direction and 1.8 cm in the vertical direction, and the RTK positioning accuracy for short baselines will not exceed 3 cm in the horizontal direction and 5 cm in the vertical direction. The homemade standalone BDS receiver has initially possessed the ability to independently provide reliable high-precision positioning services.

Key words: BDS, performance evaluation, signal quality, measurement noise, PPP, baseline solution, RTK positioning