Flaw location from perpendicular NDE ultrasonic transducers using the wavelet packet transform

Ultrasonic inspection of materials from different planes is a technique that produces complementary information of the same piece using different echographic traces. The combination of these traces in order to obtain an improved representation of the inspected area is a problem that can be solved by means of digital signal processing techniques. A new method for the combination of the traces coming from perpendicular transducers is presented in this paper. The method is based on the undecimated wavelet packet transform and it is applied to the localization of isolated flaws in a plastic piece.