非差改正数的多GNSS恒星日滤波方法

Sidereal filtering based on zero-differenced error corrections for multi-GNSS

多路径误差是全球卫星导航系统(GNSS)精密数据处理的主要误差源之一,观测值域的恒星日滤波是应用较为广泛的多路径误差削弱方法,但其在多系统应用中存在映射方法相对低效的问题,且缺乏针对Galileo的应用研究。为解决现有方法不适用于大规模网解数据处理的弊端,该文提出了一种基于非差改正数的多GNSS系统恒星日滤波方法,从理论上证明了该方法在进行多路径误差改正时的效果与双差观测值域恒星日滤波方法的等价性,并提出了该方法在Galileo中的应用服务方案。对一组采集于2018年年积日219—231 d的多系统数据进行了多路径误差改正实验分析,观测值域的双差残差测试结果表明,GPS、BDS和Galileo的双差残差统计精度得到了显著的提升,频域分析结果也表明多路径误差的低频部分能被有效削弱。坐标域的静态定位结果显示,强多路径环境下GPS和BDS联合定位精度在三维方向上相对于单GPS有一定改善,加入Galileo数据后相对于单GPS可进一步提升。

Multipath error is one of the main error sources in high-precision data processing of global navigation satellite system(GNSS). Sidereal filtering in observation domain is a widely used multipath error mitigation method. However, the sidereal filtering method based on observations are relatively inefficient in applications of multi-GNSS and the relevant research on Galileo has not been carried out. In order to solve the problem that the existing methods are not suitable for data processing for large GNSS network solution, a sidereal filtering method based on zero-differenced error corrections for multi-GNSS was proposed in this paper. Theoretically proved the equivalence of the effect of the new method in multipath error correction and sidereal filtering based on the double-differenced algorithm. And the application service scheme of this method in Galileo was proposed. An experimental analysis of multipath error correction was carried out for a group of multi-GNSS data collected from 219 to 231 days in 2018,the statistical accuracy of double-differenced residuals of GPS,BDS and Galileo systems was significantly improved in the observation domain, the frequency domain analysis results also showed that the low frequency part of multipath error was effectively weakened. For the static positioning test results, the positioning results of GPS and BDS after multipath error correction in the strong multipath environments were improved in 3 directions compared with GPS,and the positioning accuracy of three systems with Galileo was further improved compared with GPS.