基于频谱细化的线性调频信号的参数估计。首先对中频信号延时相乘然后对产生的序列做FFT，初步算出LFM信号的调频斜率，然后用CHIRP-Z变换精确估计。-Estimated based on the parameters of the linear FM signal spectrum refinement. First of delay multiplied by the IF signal and then do the FFT on the resulting sequence, initi