“…To avoid the Runge phenomenon, which happens when a signal's instantaneous frequency (IF) suffers from strong oscillations, the SCT utilises a spline kernel to describe such an NLFM signal [14]. The chirplet chain methods [15] are made based on the search for a single best path in the T–F domain. For the implementation of the CT, the discrete chirp Fourier transform is convenient because of using fast Fourier transform (FFT) operation [16].…”