Study On The Characteristics And Recognition Algorithms Of The First Wave From The Sea Floor

In this paper,we mainly study on the algorithm of identifying the first-arrival wave of ship seabed seismic waves.The purpose is to avoid the shortcomings of the fractal algorithm and the wavelet transform algorithm and to use the advantages of the both two algorithms to form the fractal dimension and the wavelet transform compound algorithm so as to reduce the computation amount of the first-arrival wave recognition and improve the accuracy of the first-arrival wave recognition.The propagation characteristics of seismic wave in ship seabed are expounded.Length fractal dimension algorithm is used to identify the first-arrival wave of the simulated signal and the actual acquired seismic wave signal.Using wavelet transform algorithm and different types of wavelet base to filter the seismic signal to noise reduction.Comparing the optimal wavelet base to select the best wavelet base to denoise the seismic signal,and then use the discrete wavelet transform to reconstruct the seismic signal,and identify the first-arrival wave.This paper analyses the advantages and disadvantages of Length fractal dimension algorithm and wavelet transform algorithm,which are two traditional first-arrival recognition algorithms.By using the advantages of the two traditional first-arrival recognition algorithms,this paper proposes the assumption of composite algorithm based on fractal and wavelet transform.The simulation of the self-similar signal to the fractal and wavelet transform algorithm to verify the feasibility of the composite algorithm.Through the simulation of shallow seabed seismic wave model to acquire the seismic wave datas,using composite algorithm of fractal and wavelet transform of seismic wave signal collected to identify the first-arrival wave.The simulation result shows that the composite algorithm improves the recognition accuracy of the first-arrival wave,and reduces the calculation of identifying the first-arrival wave.