Characterization of flaws using the poles and zeros of the transfer function of the corresponding ultrasonic system

This investigation deals with a technique of flaw characterization which exploits the spectral phase of the echographic signal as a principal parameter. A method has been developed to determine the distribution of the poles and zeros of the transfer function of the echographic system in the complex plane. It seems to be easier to exploit this distribution rather than dealing directly with the spectral amplitude and phase. The results obtained on several artificial flaws are presented.