Pulse-echo method can't measure wave attenuation accurately

TL;DR

This paper demonstrates that the pulse-echo method cannot reliably measure wave attenuation in solids and liquids, as the attenuation constants derived from echo measurements deviate from the true intrinsic attenuation.

Contribution

The study provides a numerical analysis showing the inherent inaccuracies of the pulse-echo method in estimating true wave attenuation.

Findings

Pulse-echo attenuation estimates differ from intrinsic values

Numerical analysis highlights limitations of exponential fitting

Inaccuracy persists even in ideal wave propagation conditions

Abstract

A number of techniques with different degrees of accuracies have been devised for the measurement of acoustic wave attenuation in solids and liquids. Still, a wide variation is observed in the attenuation values in different materials reported in the literature. Present numerical study based on a 'propagating wave' model analysis clearly shows that the attenuation constant obtained from exponential fitting of the echo heights in pulse-echo method differs from the exact value of intrinsic attenuation in the medium, even in the ideal situation of plane wave propagation without diffraction, dispersion or scattering.