目标跟踪，程序利用卡尔曼滤波器对对圆周运动的目标进行跟踪。绘制出期望信号、观测信号和滤波后点目标的运动轨迹。-Target tracking, the program the use of Kalman filter, right, right circular motion of the target being tracked. Draw out the desired signal, observation point target signal and the filtered trajectories.