设定雷达和目标参数，选取目标中心与雷达的距离为参考距离，采取dechirp方式接收信号，直接对回波信号进行二维FFT得到的成像结果，并采用Keystone法（即重采样法）校正越距离单元徙动。-Set the radar and the target parameters, select the center of the target and the distance from the radar as the reference distance, take reception dechirp