Analysis of Ultrasonic Signals based on Wavelet Cross Spectrum

Abstract

This paper discusses the results of application of wavelet cross spectrum on Ultrasonic A-Scan signals that have been acquired by moving across the top surface of a cylindrical object placed vertically and immersed in a tank of water. Due to the phenomenon of beam spread, the ultrasonic transducer detects the object even when the transducer is slightly away from the object. As the transducer traverses across the object, the peak amplitude of the A- Scan signals increase and then decrease. Wavelet cross spectrum is found to be successful in identifying the signals that have been acquired with the position of the transducer exactly focusing the object.