Characteristics of the BDS Carrier Phase Multipath and Its Mitigation Methods in Relative Positioning.
Characteristics of the BDS Carrier Phase Multipath and Its Mitigation Methods in Relative Positioning.
复制标题
DOI：
10.3390/s17040796
复制
发表时间：
2017-04-07
期刊：
影响因子：
--
通讯作者：
Cai C
中科院分区：
文献类型：
--
作者：
Dai W;Shi Q;Cai C
载波相位多径效应是影响北斗卫星导航系统精确定位的主要误差源之一。分析了北斗系统的多径特性，发现静止地球轨道（GEO）卫星信号的多径误差具有系统性，而倾斜地球同步轨道（IGSO）或中地球轨道（MEO）卫星信号的多径误差具有系统性和随机性。采用改进的多径缓解方法，包括恒星滤波算法和多径半球映射（MHM）模型，改进北斗系统动态变形监测。结果表明，恒星滤波方法在坐标域和观测域的定位误差均方根分别降低15%、37%、25%和18%、51%、27%。相比之下，MHM方法平均可将RMS降低22%、52%和27%。此外，在多路径丰富的环境下，静态基线方案的BDS多路径误差与全球定位系统（GPS）多路径不同，误差在几厘米以内。因此，我们在平差模型中加入了一个代表观测方程中GEO多径误差的参数，以提高BDS静态基线解的精度。结果表明，改进后的模型在东、北、上坐标方向的平均精度分别提高了82%、54%和68%。
The carrier phase multipath effect is one of the most significant error sources in the precise positioning of BeiDou Navigation Satellite System (BDS). We analyzed the characteristics of BDS multipath, and found the multipath errors of geostationary earth orbit (GEO) satellite signals are systematic, whereas those of inclined geosynchronous orbit (IGSO) or medium earth orbit (MEO) satellites are both systematic and random. The modified multipath mitigation methods, including sidereal filtering algorithm and multipath hemispherical map (MHM) model, were used to improve BDS dynamic deformation monitoring. The results indicate that the sidereal filtering methods can reduce the root mean square (RMS) of positioning errors in the east, north and vertical coordinate directions by 15%, 37%, 25% and 18%, 51%, 27% in the coordinate and observation domains, respectively. By contrast, the MHM method can reduce the RMS by 22%, 52% and 27% on average. In addition, the BDS multipath errors in static baseline solutions are a few centimeters in multipath-rich environments, which is different from that of Global Positioning System (GPS) multipath. Therefore, we add a parameter representing the GEO multipath error in observation equation to the adjustment model to improve the precision of BDS static baseline solutions. And the results show that the modified model can achieve an average precision improvement of 82%, 54% and 68% in the east, north and up coordinate directions, respectively.