Abstract

In ultrasonic nondestructive testing (NDT) of materials, pulse echo measurements are masked by the characteristics of the measuring instruments, the propagation paths taken by the ultrasonic pulses, and are corrupted by additive noise. It is assumed that the measured pulse echo is obtained by linearly convolving the defect impulse response with the measurement system response. Deconvolution operation therefore, seeks to undo the effect of the convolution and extract the defect impulse response which is essential for defect identification. In this contribution, we show that higher order statistics (HOS)-based deconvolution is more suitable to unravel the effect of the measurement systems and the effect of additive Gaussian noise on the defect impulse response. Synthesized ultrasonic signals are used to validate the proposed technique and to show that it excels those deconvolution techniques that are based on second order statistics (SOS).

Keywords: Ultrasonic Testing

Source: Conference Proceedings of the 4th International Conference of the Slovenian Society for Nondestructive Testing, 24 - 25 April 1997, Ljubljana, Slovenia.
Pages:83 - 88

Publisher:
Slovenian Society for Nondestructive Testing, Faculty of Mechanical Engineering, Askerceva 6, SLO 1000 Ljubljana, Slovenia. Tel +386 61 177 12 03, Fax +386 61 218 567, Email: janez.grum@fs.uni-lj.si.