Fourier Transform Ultrasound Spectroscopy For the Determination of Wave Propagation Parameters

TL;DR

This paper introduces Fourier Transform Ultrasound Spectroscopy (FTUS) as a method to accurately determine wave number and attenuation in water, addressing inconsistencies in traditional ultrasonic attenuation measurements.

Contribution

The study applies FTUS to measure ultrasonic wave parameters in water, providing a novel approach that improves accuracy over existing pulse-echo techniques.

Findings

FTUS yields consistent attenuation constants in water.

Wave number and attenuation are accurately determined at 1MHz.

Results align well with literature values.

Abstract

The reported results for ultrasonic wave attenuation constant ({\alpha}) in pure water show noticeable inconsistency in magnitude. A "Propagating-Wave" model analysis of the most popular pulse-echo technique indicates that this is a consequence of the inherent wave propagation characteristics in a bounded medium. In the present work Fourier Transform Ultrasound Spectroscopy (FTUS) is adopted to determine ultrasonic wave propagation parameters, the wave number (k) and attenuation constant ({\alpha}) at 1MHz frequency in tri-distilled water at room temperature (25oC). Pulse-echo signals obtained under same experimental conditions regarding the exciting input signal and reflecting boundary wall of the water container for various lengths of water columns are captured. The Fast Fourier Transform (FFT) components of the echo signals are taken to compute k, {\alpha} and r, the reflection constant at the boundary, using Oak Ridge and Oxford method. The results are compared with existing literature values.