In Non Destructive Testing, defect detection is affected by noise and/or overlapping of reflected signals in thin samples. Thus, it is necessary to enhance visibility and resolution of defects echoes by signal processing techniques. The proposed methods are Wavelet and Wiener-Ville Transforms. They are tested on real ultrasound signals, collected from an experimentation using the technique pulse-echo immersion in longitudinal direction, for cement paste and mortar.
Good results are obtained confirming the robustness of the proposed methods on detection/localization of defects in materials and demonstrating the feasibility, simplicity and effectiveness of these methods.