面向城市复杂环境的3种多频多系统GNSS单点高精度定位方法及性能分析  

Three multi-frequency and multi-system GNSS high-precision point positioning methods and their performance in complex urban environment

作　　者：耿江辉[1] 常华 郭将 栗广才 魏娜[1] GENG Jianghui;CHANG Hua;GUO Jiang;LI Guangcai;WEI Na(GNSS Research Center, Wuhan University, Wuhan 430079, China)

机构地区：[1]武汉大学卫星导航定位技术研究中心

出　　处：《测绘学报》2020年第1期1-13,共13页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(41674033)~~

摘　　要：城市智能交通、自动驾驶等对高精度动态定位的需求为分米级甚至厘米级,但在城市复杂环境下信号遮挡、衰减和多径频繁发生,GNSS定位的可用性和精度严重降低。本文充分利用现有可用的多频多系统GNSS(GPS/BDS/Galileo/QZSS)数据,采用最新提出的单历元PPP宽巷模糊度固定方法(PPP-WAR),并与传统PPP方法和广域伪距增强精密定位方法进行对比试验,分析了这3种单点高精度定位方法在大都市高楼密布道路、小城镇狭窄道路和工业区开阔道路3种不同信号遮挡条件下的车载动态定位性能。结果表明,目前城市环境中的三频数据完整性高达94%以上,可满足基于多频GNSS单历元定位的需求。粗差阈值设定为3 m时,单历元PPP-WAR解在小城镇狭窄道路的水平定位误差RMS为0.41 m,达到了分米级定位精度,比广域伪距增强精密定位解和传统PPP解分别提高了53.9%和21.2%;3种方法在大都市高楼密布环境下的定位可用性均高于70%,在另外两种城市环境下的定位可用性均高于90%。粗差阈值0.5 m时,单历元PPP-WAR方法和传统PPP方法在小城镇狭窄道路环境中可用性依然可达~70%。单历元PPP-WAR方法受城市环境中4种典型地物(地下通道、高架桥、行道树和高楼)的影响最小。总之,在干扰因素多的城市复杂环境中单历元PPP-WAR方法更具优势,在干扰因素少的城市开阔环境中传统PPP方法更优。High-precision applications,such as intelligent transportation and automated driving in urban environment,require a dynamic positioning accuracy at decimeter to centimeter level.However,GNSS performance(such as availability and positioning accuracy)in urban environments is strongly degraded by man-made and natural objects that obstruct satellite signals.Taking advantage of the available multi-frequency and multi-system GNSS(GPS/BDS/Galileo/QZSS)data,we adopt the new single-epoch PPP wide-lane ambiguity fixing method(PPP-WAR)for vehicle dynamic positioning.It is compared with the traditional PPP method and wide-area pseudorange enhanced precision positioning method in three typical urban environments with different complexity,including a road in metropolitan area,a narrow road in small town and an open road in industrial area.The integrity of triple-frequency GNSS data is currently up to 94%in urban area,which assures that single-epoch PPP-WAR method is applicable in complex urban area.It’s shown that a positioning accuracy of 0.41 m in the horizontal direction is achieved using the single-epoch PPP-WAR method in the narrow road in town with the threshold of 3.0 m,which satisfies the accuracy requirement at decimeter level.The accuracy is largely improved by 53.9%and 21.2%compared with those of wide-area pseudorange enhanced precision positioning solutions and traditional PPP solutions,respectively.The availability of three methods in metropolitan area is higher than 70%,as well as more than 90%in small town and industrial area.The availability of PPP-WAR and traditional PPP can still reach^70%with a strict threshold of 0.5 m.Four typical features(i.e.tunnels,crossovers,street trees and skyscrapers)in urban environment have the least impact on the performance of single-epoch PPP-WAR among the three methods.In sum,single-epoch PPP-WAR method has the best performance in complex urban environment with more obstructions,while traditional PPP method is the best in open urban environment with less obstructions.

关 键 词：单点高精度定位 多频多系统GNSS 城市环境 单历元 宽巷模糊度固定 

分 类 号：P228[天文地球—大地测量学与测量工程]