基于北斗Ka星间链路的地面用户导航方法

针对导航系统L频段信号易受到有意或无意的干扰和欺骗，而导致地面区域性导航服务性能下降甚至失效的问题，提出了一种利用北斗Ka星间链路信号为地面用户提供导航服务的方法。首先，对该方法的可行性进行了研究，并给出了星间链路时分体制下的用户测距模型;然后，提出了基于时钟模型和惯导信息的测距值历元归算方法，并推导了基于北斗星间链路测距值的地面用户实时定位算法;最后，通过数值仿真分析了不同因素对算法性能的影响。仿真结果表明，该方法定位精度可达2.0 m以内，能够在一定程度上弥补L频段导航信号区域性失效带来的缺失。

Navigation Method for Terrestrial Users Based on Beidou Ka Inter Satellite Links

The L-band navigation signals are easily affected by the intentional or unintentional interference and spoofing, which may lead to the regional performance degradation or even failure of the navigation system. This paper presents a new navigation approach for the terrestrial users based on Beidou Ka inter-satellite links. Firstly, the feasibility of the approach is ascertained and the measurement model under time division system is given; Then, an epoch reduction method for the Ka measurements is proposed using the receiver clock model and the measurements from the inertial navigation system, based on which the Beidou Ka inter-satellite link based real time navigation algorithm for the terrestrial users is derived; Finally, the influence of different factors on the performance of the algorithm is analyzed by the numerical simulations. The simulation results show that the proposed algorithm can achieve a satisfactory position precision within 2.0 meters, which can compensate for the lack of the regional failure of the L-band navigation signals to a certain extent.