Pile integrity testing signal analyses with one dimensional continuous wavelet transform

Non-destructive testing methods (NDT) gain its popularity while used to evaluate the integrity of underground structure due to its economic an fast testing advantage. However, the transit signals acquired from sensor will tend to be complicated as the defects exist. To identify the defects from complex signal becomes so difficult that a misjudgment may be occurred. Recently, the wavelet transform technique has been applied to a wide variety of signal analyses. This paper applies the continuous wavelet transform method (CWT) to enhance the characteristics of the tremors, in order for a better identification. The results show that the CWT is more suitable for problems while a more precise time resolution is required for higher frequencies than for the lower ones. This makes the CWT better for the locating of discontinuities or singularities which ever the high frequency terms dominate. The wavelet transform effectively zooms in on the temporal signal whenever analyzing higher frequencies so giving a greater resolution which we want to realize. It also prove that the CWT indeed a suitable way to help explication and judgment the results from Sonic Echo (SE) method easily and precisely.