On fractional Fourier transform moments

Based on the relation between the ambiguity function represented in a quasi polar coordinate system and the fractional power spectra, the fractional Fo urier transform (FT) moments are introduced. Important equalities for the g lobal second order fractional FT moments are derived, and their application s for signal analysis are discussed, The connection between the local momen ts and the angle derivative of the fractional power spectra is established. This permits us to solve the phase retrieval problem if only two close fra ctional power spectra are known.