Distortion characterization for non-normal incidence in pulse-echo ultrasound

Author

Orofino, D.P. ; Pedersen, P.C.

Author_Institution

Dept. of Electr. Eng., Worcester Polytech. Inst., MA, USA

fYear

1989

fDate

3-6 Oct 1989

Firstpage

1073

Abstract

A technique for determining the spectral distortion of received echo signals due to angular misalignment between the transducer and plane specular targets is presented. Pulse-echo measurements carried out on stratified media, the interfaces of which have small angular deviations from normal incidence, suffer such spectral distortion due to phase-cancellation (diffraction) effects across the face of the transducer. The object of this investigation is to compute this distortion effect in the nearfield of an unfocused circular piston transducer for the case of an arbitrary angular misalignment of an infinite, planar reflecting surface. The spectral distortion produced is characterized over frequency, angular misalignment, transducer geometry, and distance to the reflector. Experimental verification of the results is presented for several misalignment angles and transducer geometries using pulse-echo measurements

Keywords

acoustic imaging; ultrasonic measurement; angular misalignment; infinite planar reflecting surface; non-normal incidence; phase cancellation effects; plane specular targets; pulse-echo ultrasound; received echo signals; spectral distortion; transducer; unfocused circular piston transducer; Diffraction; Distortion measurement; Frequency; Geometry; Nonhomogeneous media; Phase distortion; Phase measurement; Pistons; Pulse measurements; Transducers;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1989. Proceedings., IEEE 1989

Conference_Location

Montreal, Que.

Type

conf

DOI

10.1109/ULTSYM.1989.67154

Filename

67154