北斗星基增强系统增强定位方法和效果研究

Study on enhanced positioning method and effect of BDSBAS

北斗星基增强系统BDSBAS通过地球同步轨道卫星实时播发导航卫星星历改正数等增强信息,提高用户全球导航卫星系统定位精度,提升服务水平,是北斗全球卫星导航系统的重要组成部分。根据相关标准协议文件研究了BDSBAS增强定位算法,并在自主研发的北斗星基增强系统监测接收机上设计实现了BDSBAS增强信号的接收,完成了单频和双频实时增强定位解算。实测结果表明:BDSBAS-B1C增强信号能有效提高GPSL1C/A的单频定位精度,相比于标准服务单频定位结果,水平和高程方向精度分别提升了45.18%和70.61%,提升后定位精度在1 m左右;BDSBAS-B2a增强信号能一定程度提高BDS B1C-B2a的双频无电离层组合定位精度,相比较于标准服务双频定位结果,水平和高程方向精度分别提升了6.15%和5.83%,提升后定位精度达到分米级。

BDSBAS is an important part of BDS. It improves the positioning accuracy and service level of GNSS by broadcasting the ephemeris corrections and other augmentation information through geostationary earth orbit satellites in real time.This paper studies the enhanced positioning algorithm of BDSBAS according to the relevant standard protocol files, designs and realizes the receiving of the signal of BDSBAS on the BDSBAS monitor receiver, and completes the real-time enhanced positioning solution of single frequency and dual frequency. The results show that BDSBAS-B1C signal can effectively improve the single-frequency positioning accuracy of GPS L1C/A. Compared with the standard service single-frequency positioning, the positioning accuracy of horizontal direction and elevation direction is increased by 45.18% and 70.61%, and the positioning accuracy is about 1m after the enhancement. BDSBAS-B2a signal can improve the positioning accuracy of BDS B1C-B2a dual-frequency ionosphere-free combination to a certain extent. Compared with the standard service dual-frequency positioning,the positioning accuracy of horizontal direction and elevation direction is improved by 6.15% and 5.83%, and the positioning accuracy reaches decimeter level after the enhancement.