GPS/BDS组合导航系统的精密单点定位模型

Precision single point positioning model of GPS/BDS integrated navigation system

为了改善单卫星导航系统由于卫星数量较少,导致定位误差高的问题,设计全球定位系统(GPS)/北斗卫星导航系统(BDS)组合导航系统的精密单点定位模型:线性组合处理GPS与BDS的伪距和载波相位观测值,并构建GPS/BDS组合导航系统的组合观测值;接下来利用协方差成形自适应卡尔曼滤波方法,对组合导航系统导航过程中的卫星钟差、电离层延迟等误差实施滤波;再利用滤波处理后组合导航系统的广播星历,获取卫星轨道以及钟差;然后利用经验模型修正对流层延迟,获取相位观测值与伪距的综合改正数;最后利用综合改正数修正组合导航系统的观测方程,构建精密单点定位模型。实验结果表明,GPS/BDS组合导航系统采用所构建模型进行精密单点定位,不同方向定位误差均低于10 cm,证明了提出模型的有效性。

In order to improve the problem of high positioning error caused by a small number of satellites in single satellite navigation system,the paper designed a precise single point positioning model for the global positioning system(GPS)/BeiDou navigation satellite system(BDS)integrated navigation system:linear combination was used to process the pseudo range and carrier phase observations of GPS and BDS,and the combined observations of GPS/BDS integrated navigation systems were constructed;subsequently,the covariance shaping adaptive Kalman filtering method was used,and the errors such as satellite clock deviation and ionospheric delay during the navigation process of the integrated navigation system were filtered;next,the filtered broadcast ephemeris of the integrated navigation system was used to obtain the satellite orbit and clock deviation;then,the empirical model was used to correct the tropospheric delay for obtaining the comprehensive correction number of phase observation values and pseudo range;finally,the observation equation of the integrated navigation system was corrected by using the comprehensive correction number,and a precise single point positioning model was constructed.Experimental result showed that the positioning error in different directions would be all less than 10 cm when the GPS/BDS integrated navigation system uses the proposed model for precise single point positioning,which could prove the effectiveness of the proposed model.