Wavelet Coefficient Threshold Based Seismic Signal Denoising Method Research

Seismic signal's analysis and process is the important basis for earthquake monitoring and early warning.It is an important method for seismic signal to analyze the effective signal from the frequency of the complex seismic signal to reduce the frequency of the noise signal.Common methods of seismic signal denoising include modal decomposition,S transform,noise reduction and wavelet threshold.The hard and soft threshold method in the wavelet threshold method is the common method of seismic signal denoising,but it is easy to cause the loss of high frequency information in the signal,which leads to the occurrence of earthquake misjudgment and leakage.Seismic signal monitoring process inclusions noise signal which wavelet analysis method can reduce the noise signal energy to achieve noise reduction.The seismic signal monitoring process contains the noise signal,in which the low frequency part is the noise signal.The wavelet comprehensive threshold is used to reduce the noise of the high frequency signal and the soft threshold is used to lower the low frequency part.Energy spectrum coefficient analysis method can directly analyze the effect of noise reduction and the simulation results show that the energy of the effective signal in the simulated seismic signal is strong,and the energy of the high frequency is more concentrated by the wavelet combined threshold method.The effective signal of the low frequency part is enhanced and the original signal is reconstructed more completely.