北斗星基增强系统性能提升初步评估

Preliminary Evaluation of Performance of BeiDou Satellitebased Augmentation System

摘要:

介绍了北斗星基增强系统及广域差分改正数算法.采用10个测站6 d的相位平滑伪距和相位观测数据，初步评估了北斗星基增强系统性能提升后的用户定位性能.结果表明：用户相位平滑伪距增强定位精度在东、北和天顶3个方向上分别达到0.3 m、0.4 m和0.8 m，相对于普通导航平均三维提高了53%；基于精密单点定位技术的用户相位增强定位坐标平均在7 min内收敛到1 m以内，收敛之后水平坐标精度能达到0.1 m，高程坐标精度能达到0.2 m，两项指标都优于基于外部后处理精密轨道钟差的精密单点定位结果.

Abstract:

BeiDou navigation satellite system (BDS) integrates legacy PNT and authorized differential service, where differential service is provided by the satellitebased augmentation system (SBAS). The latest progress of the BDS SBAS development were introduced and the performance of pseudorange based and carrier phase based user differential positioning was evaluated. Observations of 10 stations in Chinese mainland were used. The results show that the coordinate accuracy of the pseudorange differential positioning (SBAS SPP) reaches 0.4 m, 0.3 m and 0.8 m in the North, East and Up directions respectively, which shows an improvement of 53% over the legacy SPP. For the evaluation of carrier phase based positioning, kinematic precise point positioing (SBAS PPP) was performed and compared to the kinematic PPP results based on post processing precise satellite orbits and clocks (POST PPP). The results show that the SBAS PPP kinematic coordinate estimates converge to 1 meter in 7 mins on average and the coordinate accuracy reaches 0.1 meter in horizontal and 0.2 meter in vertical component after convergence. Compared to the results of POST PPP, SBAS PPP shows better accuracy and shorter converge time, which indicates that the accuracy of BDS satellite orbits has been increased and clocks still have to be improved.