Application of the Wavelet Transform in Ultrasonic Echo Signal Processing

In the field of ultrasonic non-destructive testing, often encounter the problem of noise. In the detection process, the ultrasonic transmission medium are uneven, and the detection of different objects, the content and composition of impurities are not the same, even though vary greatly, which will lead to high-frequency signal and noise signal superimposed together to reduce the detection the accuracy and precision. In this paper, the use of wavelet transform technology has been introduced, using its multi-resolution characteristics and Mallat algorithms, it take ultrasonic echo signal to carry out time-frequency signal analysis and processing, through advanced graphical programming software LabVIEW to achieve its de-noising process. The results show that wavelet transform can effectively restrain noise signal, the SNR has been improved obviously.