First Arrival Pickup Of Seismic Waves Based On Mutual Information

Energy problems are the big event which concerns the national economy and the people's livelihood, petroleum plays an more and more important role in our daily life, the accurate exploration of petroleum has an important meaning for us. To realize accurate petroleum exploration, first, we should handle plenty of signals of seismic waves, and the first arrival pickup is a basic and very important problem which we handle the signal of seismic wave.First arrivals pickup of seismic waves applied in the investigation method of surface layer and the survey of geological structure, first arrivals detecting of seismic waves are important for the development of mineral resource and petroleum resource at all time, this paper studies how to detect first arrivals of seismic waves. By far, many methods and theories have been put forward, such as ratio of energy method, maximal amplitude method, fractal dimension method and neural network. However, these methods have disadvantages themselves. This paper studies is what the first arrival pickup based on mutual information of seismic waves, the concept of mutual information comes from information theory, which is used for surveying the similarness between two radom variables. Therefore, mutual information content in information theory is introduced to the processing of seismic signals, and we put forward a kind of mutual information algorithm, which can detect the signal of seismic and the first arrival. We have given the basic principle and the specific algorithm of this method, We combine traditional ratio of energy method and this mutual information algorithm,then put forward a kind of new improved algorithm. In the end we compare this mutual information method, improvement method, ratio of energy method, ratio of amplitude method and curve length method,and we find that mutual information method and improvement method reduce amount of calculation greatly, which can accurately pick up the time of first arrival of seismic waves.