一种多模GNSS接收机系统时间偏差求解方法

One Method on Multi-System GNSS Receiver System Time Bias Solution

系统时间偏差是在多模卫星导航接收机中兼容和互操作方面的一个重要问题.传统的方法在多模接收机主Kalman滤波器中增加一个时间偏差状态量,数据融合的同时解决系统时间偏差问题.这种处理方法需要在主Kalman滤波器中对不同系统的测量值分别处理.考虑到卫星系统时间差和信号硬件延迟相对缓变这一事实,提出了一种新的系统时间互操作方法.利用一个独立运作的Kalman滤波器实时估计系统时差,这样接收机的主滤波器不需要增加新状态,测量矩阵构建时可以对不同系统测量值同样对待.经过GPS/BD多模接收机实际信号的对比测试验证,新方法与传统方法相比性能相当.

Timing aspect of interoperability between GNSS systems is one of the key issues in multi-system GNSS applications. It is important to deal with the system time bias （STB） problem properly especially in unaided receivers. Traditional multi-system receivers solve this problem by adding an additional state in main KALMAN filter. Considering the STBs are relatively slow-varying variables, this paper proposes an innovative real time approach to estimate the system time bias between different satellite navigation systems. With the assistant of estimated system time bias, additional filter states is avoided and a simple and efficient measurement matrix can be constructed. Through several tests in a GPS/BD receiver, we can conclude that the new method has performance comparable with the traditional one.