The Research Of Automatic First Break Picking Based On EEMD

In seismic exploration,the processing is a key part and its quality can directly affect the final result.As the basic process of the processing,the first arrival picking also has an important influence on the processing output.Until now,many methods have been developed to calculate the first break travel time,however,each method has its own limitations.In this paper,a new technique—EEMD(Ensemble Empirical Mode Decomposition)is introduced which is suitable to analysis the non-stationary signal.Because the seismic wave is the non-stationary signal,we propose a new method based on EEMD for the first arrival picking.Threshold de-noising is widely used in the processing,however,some information in the signal is lost while the noise is removed.In this paper,a new modified method is presented.This method can not only retain the original signal as much as possible while suppressing noise,but also can enhance the characteristics of the first arrival.With the technology of autocorrelation and wavelet contrast,we can realize the automation of the whole picking process.Model testing and field data show the effectiveness and stability of our method.Our method can also be applied to pick the first break for the large amount of data.