主要过程是：将一段纯净信号加入噪声，变成带噪信号，对带噪信号进行卡尔曼滤波，计算前后的信噪比，画出时域图。进行比较。(The main process is to add a piece of pure signal to noise and turn it into a noisy signal. Calman filter is applied to the noisy signal, and the SNR is calculated before and after, and the t