GPS多路径重复性试验研究  

Experimental analysis of GPS multipath day-to-day repeatability

作　　者：钟萍[1,2] 袁林果[1,2] 丁晓利[2] 

机构地区：[1]西南交通大学土木工程学院测量工程系,成都610031 [2]香港理工大学土地测量与地理咨询学系

出　　处：《测绘科学》2010年第2期43-45,26,共4页Science of Surveying and Mapping

基　　金：香港特别行政区研究资助局项目(PolyU5148/04E);西南交通大学科研启动基金(编号:A0320502050901-2)

摘　　要：信号衍射和多路径效应是限制GPS定位精度进一步提高的瓶颈,观测中两者往往同时存在。衍射效应具有不完全重复的特性,为了研究多路径重复性并使其不受信号衍射的影响,本文提出先应用SIGMA-Δ信噪比加权模型削弱信号衍射的影响,再运用改进恒星时滤波法分析多路径重复性。实验观测资料分析表明,SIGMA-Δ模型能有效削弱衍射信号对定位结果影响,并且保留主要的多路径信号;而改进恒星时滤波法能适应测站周围多路径环境的变化,从而最大限度地削减多路径误差。两者组合比传统的恒星时滤波更能有效提高GPS的动态定位精度。Signal diffraction and muhipath disturbance are bottleneck problems that limit accuracy of Global Positioning System （GPS） positioning, both of which tend to exist simultaneously. However, the day-to-day repeatability of signal diffraction is not obvious. To take advantage of the day-to-day repeating property of GPS multipath signals and make it not affected by diffraction effects, this paper used the stochastic SIGMA-A model to reduce the effects of signal diffraction and then applied the modified sidereal filtering to analyze the multipath repeatability. Experiments with real GPS observations showed that the SIGMA-A model could achieve a balance between reducing the diffraction effects and keeping the main muhipath signals. The modified sidereal filtering used time-varying and site-dependent shifts to fully mitigate the multipath error. It was shown that integrating the two techniques was more effective in improving the dynamic GPS accuracy than the traditional sidereal filtering.

关 键 词：GPS 多路径效应 衍射 重复性 改进恒星时滤波 

分 类 号：P228.4[天文地球—大地测量学与测量工程]