The measurement of backscatter coefficient from a broadbandpulse-echo system: a new formulation

摘要

A new formulation for obtaining the absolute backscatterncoefficient from pulse-echo measurements is presented. Using thisnformulation, performing the diffraction correction and systemncalibration is straightforward. The diffraction correction function fornthe measurement of backscatter coefficient and the acoustic couplingnfunction for a pulse-echo system are defined. Details of these functionsnfor two very useful cases are presented: a flat disk transducer and anspherically focused transducer. Approximations of these functions arenalso provided. For a flat disk transducer, the final formulation appearsnas a modification to the established Sigelmann-Reid formulation. For anfocused transducer, the final correction is a weak function of frequencynwhen the scattering volume is near the focal area, rather than thenfrequency squared dependence proposed by earlier investigators