对于级联式INS/GPS深组合导航系统,用修正后的惯导解算信息和星历信息计算的载波NCO控制量精度无法满足载波跟踪的要求,通常利用基带信号预处理滤波器的估计结果直接闭合载波环.传统的基带信号预处理滤波模型采用的是单一滤波器,因滤波器状态的相互耦合和滤波算法本身的限制,滤波估计的精度很难实现载波跟踪.基于双滤波器结构的基带信号预处理滤波模型,在传统单一滤波器基础上,新增一个3维滤波器用于闭合载波环,仿真结果表明了该方法的有效性.%For cascade INS/GPS deep integration navigation system, the computation of control value for local code and carrier Numerical Control OscillatorfNCO) needs modified inertial navigation calculation information and ephemeris information. Since the precisions of these information cannot satisfy the requirement for carrier tracking, the states of base band signal pre pre-filters are usually used to close the carrier tracking loop directly. Traditional base band signal pre-filter only contain a single filter, which is hard to close the carrier tracking loop due to the coupling of states and the limit of filtering algorithms themselves. In this paper, based on base-band signal pre-filter model of dual-filter structure, a 3-dimension filter is added into the traditional single filter to close the carrier tracking loop. Simulation results show the effectiveness of the proposed method.
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