A transfer matrix model and application spectral and time-frequency to study an ultrasonic waves backscattered by different plates immersed in water

The principle of the ultrasonic technique consists of exciting the elastic plate immersed in water by an incident plane wave, the scattering acoustic phenomena are observed and then the backscattering waves are detected. In this study, we provide a theoretical model that is developed to study and understand the acoustic scattering. This model is based on the transfer matrix, taking into account the matrix components, we obtain the reflection and transmission coefficient by appropriate relationship. Furthermore, we will present a study an acoustic signal backscattering, under a normal incident wave, for different plates (Glass and Plexiglas). The time-frequency representations such as spectrogram (SP) are used. The images obtained by these representations are compared to the frequency spectral method. Consequently, the results obtained from the time-frequency analysis are interesting. (C) 2020 Elsevier Ltd. All rights reserved.