北斗GPS双模在利用“当前”统计模型并利用kalman滤波时，其系统噪声和观测噪声未知且时变，而且加速度上下限不能自适应于未知运动规律的无人飞行器当前加速度，导致导航精度降低。该程序是相应的MATLAB仿真程序。(Beidou GPS dual mode uses the "current" statistical model and the Kalman filter. Its system noise and observation noise are unknown and time-varying, and the upper and lower limits of acceleration can not be adapted to the current acceleration of the unknown motion law of the UAV, resulting in the reduction of navigation accuracy. The program is the corresponding MATLAB simulation program.)