Use of a wavelet analysis technique for the enhancement of signal-to-noise ratio in ultrasonic NDE

In the ultrasonic inspection of coarse-grained materials, scattering from the grains often causes difficulties in identifying the flaw signal. This paper introduces basic concepts of the wavelet analysis technique. An algorithm based on the wavelet analysis is proposed to improve the signal-to-noise ratio to detect the flaw efficiently. Experimental data for austenitic stainless steel specimens with a coarse grain size are presented which show encouraging flaw detection capabilities from use of the algorithm.