The experimental signal of a multilayer structure analysis by the time-frequency and spectral methods

The objective of this study is to discuss the effectiveness of two different methods, a time-frequency representation of Wigner-Ville and a frequency spectral representation, by comparing their ability to analyse experimentally received signals backscattered by two types of multilayer structures. In this paper, we will present a study of the propagation of acoustic waves backscattered by two multilayer structures with a resonant plate ‘aluminum or glass’ and a less resonant plate ‘plexiglas’ separated by a water layer. The backscattering experiments have been performed in a water immersion tank. The images obtained of time-frequency representation are compared to the frequency spectral method. The results obtained by the time-frequency analysis are interesting and robust.