北斗卫星导航系统逆向接收溯源方法

A New Method of Generating UTC Parameters for BeiDou Navigation Satellite System

本文针对现有卫星导航系统溯源方法以及北斗卫星导航系统(BDS)独特的星座结构,提出了逆向接收溯源方法。在中国科学院国家授时中心保持的协调世界时(UTC(NTSC))守时实验室接收北斗卫星导航信号,监测获得每颗北斗卫星广播的系统时间与UTC(NTSC)的偏差,生成溯源模型参数。研究了溯源模型参数的预报策略,分析不同时长原始数据和不同阶次的预报模型对溯源模型参数预报精度的影响。逆向接收溯源方法通过改变导航电文中的溯源模型参数产生方式,不仅能够实现向协调世界时(UTC)的溯源,而且用户在不进行任何改变的情况下,通过单向接收就可以实现优于5ns的单向授时,该精度与共视精度相当,优于目前的GNSS单向授时方法。将北斗的单向授时精度由十纳秒量级提高到纳秒量级,有利于北斗卫星导航系统的推广应用。

Considering existing UTC parameters generating method and the unique constellation of BeiDou navigation satellite system （BDS）, a new method for generating UTC parameters is proposed. The time offsets between the system time and UTC （NTSC） corresponding to each BeiDou satellite are obtained through receiving the BeiDou satellite navigation signals in the laboratory which keeps UTC （NTSC）. Then, the UTC parameters of the new method is calculated. The prediction strategy of the UTC parameters is studied, and the effect of the different lengths of the original data and the different model degrees on forecast accuracy are analyzed. Only by changing the way of generating the UTC parameters, users can obtain the offset between their local time and UTC （NTSC） with the accuracy of better than 5ns by one-way receiving navigation signals. The timing precision of BeiDou using the proposed method is improved from the level of several dozen nanoseconds to several nanoseconds which is beneficial to the application and popularization of BDS.