BDS/GPS/GLONASS组合的双频单历元相对定位性能对比分析

Validation and analysis of the performance of dual-frequency single-epoch BDS/GPS/GLONASS relative positioning

随着我国北斗卫星导航系统(Bei Dou Navigation Satellite System,BDS)的建成与运行,目前具备独立服务能力的系统包括GPS,GLONASS和BDS,多系统组合已成为GNSS导航定位发展的必然趋势.基于伪距或载波相位的相对定位是目前利用GNSS实现高精度定位的主要技术手段之一.本文重点分析对比了BDS/GPS/GLONASS单系统、双系统以及三系统组合共7种模式下双频伪距和单历元载波相位相对定位性能.结果表明:(1)BDS/GPS/GLONASS组合伪距和单历元载波相位相对定位时,三系统观测值误差比分别设为1:1:2和1:1:1较合适;(2)BDS/GPS组合的性能要优于GPS/GLONASS以及BDS/GLONASS组合,BDS/GPS/GLONASS三系统组合较双系统组合可进一步改善定位性能;(3)短基线条件下(<20 km),BDS/GPS/GLONASS组合伪距和单历元载波相位相对定位精度较单BDS,GPS,GLONASS系统分别提高了48.4%,31.7%,65.7%和6.1%,12.5%,39.4%.

With the development of China’s Bei Dou navigation satellite system（BDS） in the Asia-Pacific region, GPS, GLONASS, and BDS are the only current systems that have the capability of providing independent services. Combining the three systems is an inevitable trend in GNSS-based navigation and positioning. At present, relative positioning based on either pseudo-range or carrier phase is one of the main techniques used in providing high-accuracy GNSS positioning. In this contribution, we compared and analyzed the performance of dual-frequency single-epoch relative positioning of the three systems, GPS, BDS, and GLONASS, and the combined systems, referred to as BDS/GPS, GPS/GLONASS, BDS/GLONASS, and BDS/GPS/GLONASS. The results presented show that：（1） it is appropriate to set the measurement error ratio of the BDS/GPS/GLONASS observations to 1：1：2 for combined pseudo-range relative positioning and 1：1：1 for combined single-epoch carrier phase relative positioning;（2） positioning performance using BDS/GPS is superior to that of GPS/GLONASS or BDS/GLONASS, and can be further improved using BDS/GPS/GLONASS;（3） with short baseline（〈20 km）, the improvements in accuracy of the pseudo-range and single-epoch carrier phase relative positioning of BDS/GPS/GLONASS relative to that of the single BDS, GPS, and GLONASS are 48.4%, 31.7%, 65.7% and 6.1%, 12.5%, 39.4%, respectively.