Usefulness of time-frequency treatment to an acoustic signal

In this document, smoothed pseudo Wigner-Ville (SPWD) and reassigned spectrogram (RSPD) time-frequency distributions were developed and used to analyze an acoustic signal scattered from an thin cylindrical metallic tube immersed in water. In the work, the studied tube is made of two parts. The obtained results suggest that the time-frequency methods are suitable to find various resonances of circumferential waves that are propagated around the shell, and give better concordance with the theoretical results.