New processing techniques for transient signals with non-linear variation of the instantaneous frequency in time

Various techniques for three types of transient signals with non-linear variation of the instantaneous frequency in time were analyzed. A technique called the short-time chirp-Fourier transform was developed for the first type of signal with a piecewise dependency of the instantaneous frequency in time. The second type of signal, named a higher-order chirp, is a signal with non-linear dependency of the instantaneous frequency in time. The transform method is a generalization of the classical short-time Fourier transform and the chirp-Fourier transform for the case of of the piecewise chirps.