Research Of Seismic Signal Simulation And Denoisng Based On The Wavelet Packet Transform

In actual gathering process, due to the data acquisition environment and instrument, the seismic signal is interfered by noise inevitably, with the useful signal in noise is an important factor in seismic signal processing, which has influence on signal analysis and processing in the following stage. So without lowering the resolution on the basis of the signal and reduce signal noise and noise from the strong to extract useful signals, and removing the noise of the seismic signal and improving the signal-to-noise ratio of seismic signal has important significance of improve the accuracy of seismic exploration.With the development of digital signals processing technology, many excellent de-noising methods come forth. In the seismic data de-noising, there is an important research aspect that choosing the suitable de-noising method based on the feature of seismic data. Fourier transform and short time Fourier transform are the chief methods in signal analysis, however, they suffer inherent limit: they can analysis a signal on the whole spectrum, but these methods can not get a good effect when used for the non-stationary signal de-noising. Wavelet analysis becomes a powerful tool in the last few year, because of the wavelet function is not unique, which makes the wavelet transform adaption and stable. In the same time, many de-noising methods based on wavelet transform are coming out. Furthermore they are proved to be superior to traditional Fourier transform de-noising methods. The wavelet pocket transform divide the wavelet pocket more fine, and let wavelet pocket has better ability to Time-Frequency analysis, especially, as for blast vibration signal that is no-stationary signal including lots of high frequency and medium frequency, it can analysis better in Time-Frequency local field. So wavelet pocket threshold de-noising method is better than others.In this paper, the basic theory of wavelet de-noising and its application in the simulation of seismic data are mainly researched. Firstly, analyses the characteristics of seismic signal and noise, and presents the method which applying the wavelet package transform to remove seismic signal. Secondly, we discusses the simulation method of seismic signal, proposed analog seismic signals based on wavelet packet theory, and get good results. Then presented to the application of the new threshold function based on wavelet packet threshold de-noising principle, and combined with the weighted median de-noising method. Application of this method in simulation seismic signal, and comparison of reconstruction error by calculating the quantitative, analysis of the pros and cons of the various de-noising methods. The paper also discusses wavelet basis selection problem of the seismic wavelet transform. Finally, Simulation the wavelet analysis de-noising in real seismic signal de-noising, and be implemented in host computer based on Lab VIEW, and achieved good results.