Time-frequency analysis of model based pulse scattering from a fluid-elastic interface with periodic roughness

Abstract

A null field T-matrix formalism [ I ] is used to calculate time series produced by scattering a linear frequency modulated plane wave pulse from a doubly infinite fluid-elastic interface with sinusoidal and triangular roughness. The time series are analyzed using short time Fourier and Wigner-Ville transforms and an adaptive waveform transform based on local cosine waveforms [2]. It is shown that the time-frequency (T-F) analysis provided by the adaptive waveform transform may be used to distinguish between the scatter from surfaces of different roughness types and, for this purpose, is superior to the T-F analysis provided by both the short time Fourier and Wigner-Ville transforms. '(0. + #)(;,w) = p"'(o) exp(k r) 11-521