Wavelet Transform And Application In Seismic Data Denoising

Wavelet transform,emerging as a novel technique, has been shown to be very useful in many field. Wavelet are functions that are both localized in the time and the frequency domains. Because of this property, both time and frequency characteristics of the signal are captured in Wavelet transform. Therefore, Wavelet transform was applied to noise on removal seismic record.In the paper, several typical wavelet functions were evaluated. The denoising study on testing signal provided the optimum denoising strategy. Then signal was analyzed with the global threshold denoising method in this paper. Disadvantage is shown if the signal contained high-frequency information. Because of this, the method of second-decomposition on wavelet global threshold was suggested.In practice, seismic data usually contained information of random noise for the impersonal condition. Firstly, theoretical model was studied with wavelet global threshold denoising method. For the same phase axle of steep obliquity, this denoising method is not ideal enough. So with the method of second-decomposition on wavelet global threshold, information of the same phase axle of steep obliquity was held preferably, compared with wavelet global threshold denoising method. But information of random noise was too at the same time. Farther, the data was processed second denoising with global threshold denoising method, and the effect was preferable. At last, this method was used to practical seismic data in the paper.