Method Study Of Hybrid Time-frequency Domain FWI Based On GPU Acceleration

Recent years,the Full Waveform Inversion(FWI)is becoming one of the scientific research hot points in the field of Geophysics.The high-resolution inversion results can provide reliable velocity models for the migration processing and fine elastic models for reservoir interpretation.However,there are still two main questions about the FWI need to be solved.Firstly,the forward modeling and the gradient computation need huge calculated amount.Secondly,the high nonlinearity of the objective function and the lack of low frequency component in seismic data lead the inversion to converge to local minimum easily.This paper introduces the hybrid time-frequency domain FWI based on GPU implementation,so that to improve the computation efficiency and the reliability of the inversion result.In this paper,it performs the forward modeling of acoustic wave-equation by the finite difference method,then makes a comparison between the different absorbing boundary conditions and analyzes the advantages and the disadvantages of these boundary conditions.Finally,it selects a combined Liao's absorbing boundary condition which has the advantage of well performed absorbing effect,easy programing and high efficiency.The paper introduces the classic FWI method briefly.By contrasting the results of the experiments,it adopts the hybrid time-frequency domain full waveform inversion,which can fully benefit from the easily achievable high-accuracy forward modeling in time domain and the multiscale feature of inversion in frequency domain.At the end of this paper,it represents the method of the hybrid time-frequency domain FWI based on GPU.Combining the advantages of hybrid time-frequency domain FWI method with the high efficiency of GPU implementation on forward modeling and gradient computation,it solves the problem of the huge calculated amount in a certain degree.Then through the experiments of theoretical models,it shows that the results of the models are close to the real results and the resolutions are high enough.Thus,the conclusion is that the method of hybrid time-frequency domain FWI based on GPU is feasible.