说明：  去斜处理（宽带的匹配滤波）Stretch方法是针对线性调频信号而提出的， 其方法是将输入信号与参考信号 （经适当延迟的本振信号， 延迟量通常由窄带信号测距结果估计出） 混频 ，则每一个散射点就对应一个混频后的单频分量，对混频输出的信号进行 DFT 处理 ，即可获得目标的距离像，对参考信号的要求是应具有与输入信号相同的调频斜率。
(dechirp matched filter Stretch method is proposed for linear frequency modulation signal. It mixes the input signal with the reference signal (local oscillator signal with appropriate delay, the delay is usually estimated from the result of narrowband signal ranging). Then each scattering point corresponds to a single frequency component after mixing, and DFT is performed on the mixed-frequency output signal. The range profile of the target can be obtained by processing, and the reference signal is required to have the same frequency modulation slope as the input signal.)