“…Therefore, through a one‐dimensional peak search of , , the NZ index can be estimated as According to the modulation parameters corresponding to , the LFM signal of N points can be restructured as Thus, the LFM/SFM hybrid modulated signal output by the dual‐channel NYFR is converted into a simple chirp signal. Then the fractional Fourier transform (FrFT) method [7] can be used to estimate the LFM parameters of . Assuming that the best rotation angle and peak position are estimated to be and , the chirp rate and centre frequency of the original LFM signal can be estimated as …”