GPS/BDS分类组合定位的指数加权Helmert方差分量估计法  

Exponential Weighted Helmert Variance Component Estimation for GPS/BDS Combined Positioning with Satellite Classification

作　　者：刘天骏 王坚 韩厚增 宁一鹏[1] 余航[1] LIU Tianjun;WANG Jian;HAN Houzeng;NING Yipeng;YU Hang(Key Laboratory of Land Environment and Disater Monitoring, NASMG, China University of Mining and Technology;Daxue Road, Xuzhou 221116, China;School of Geomatics and Urban Spatial Informatics, Beijing University of Civil Engineering and Architecture, 15 Yongyuan Road, Beijing 102616, China)

机构地区：[1]中国矿业大学国土环境与灾害监测国家测绘地理信息局重点实验室,江苏省徐州市大学路1号221116 [2]北京建筑大学测绘与城市空间信息学院,北京市黄村镇永源路15号102616

出　　处：《大地测量与地球动力学》2018年第7期684-688,694,共6页Journal of Geodesy and Geodynamics

基　　金：国家重点研发计划(2016YFC0803103)~~

摘　　要：针对北斗卫星导航系统(BDS)星座结构复杂、不同类型卫星观测值残差差异较大的不利条件,将BDS系统中IGSO、MEO、GEO 3种卫星的观测值进行分类定权,提出一种顾及历史权比的指数加权Helmert方差分量估计法来精确确定不同系统之间观测值的权阵。为了验证该方法在GPS/BDS组合定位中的有效性,采用单点定位模型分别进行静态和动态导航实验,并将其定位结果与等权模型以及不考虑指数加权的Helmert方差分量估计方法进行对比。结果表明,采用改进的加权方法,在东、北、天3个方向的定位精度均获得显著提高,在静态条件下,相对于等权模型,改进方法 3个方向的定位精度提高幅度分别达到50.0%、51.0%和42.0%;在动态条件下,定位精度提高幅度分别为10.0%、8.0%和9.0%。特别在卫星数量较少、卫星几何图形强度较差时,定位结果的改善效果更为明显。There are disadvantages of the BDS Navigation Satellite System（BDS）,such as complicated constellation structure and large differences in residual errors of observed values from different types of satellites.In order to precisely determine the weight matrices of observed values between different systems,this paper studies the observed values from IGSO,MEO and GEO satellites in the BDS system through classification and weighting.It proposes an exponential weighting Helmert variance component estimation method that takes historical weight ratios into account.Static and dynamic navigation tests are carried out through a point positioning model to verify the effectiveness of this improved method in GPS/BDS combined positioning,and the results of this improved method are then compared with those of the equal weighting model,as well as of the Helmert variance component estimation method without exponential weighting.Results show that with the improved method,positioning precision in east,north and zenith directions is improved significantly.Under static conditions,compared with the equal weighting model,this improved method results in 50.0%,51.0%and 42.0%improvement in positioning precision in the above three directions respectively;under dynamic conditions,relevant positioning precision is improved by 10.0%,8.0%and 9.0%respectively.Especially under situations of fewer satellites and weaker intensity of satellite geometry,improvement in positioning results is even more significant.

关 键 词：HELMERT方差分量估计 指数加权 组合定位 精密定权 GPS/BDS 

分 类 号：P228[天文地球—大地测量学与测量工程]