基于层析滤波的全波形反演方法

Full waveform inversion based on tomographic filtering

在全波形反演过程中,采集系统的有限孔径和波场对地层介质信息的非均匀覆盖会影响全波形反演的效果.本文引入一种层析滤波器来减小这种影响.该滤波器被作用于反传之前的波场残差之上,对模型梯度进行预处理,可以对有限的采集孔径和非均匀信息覆盖进行校正,从而改善全波形反演的效果.该滤波器的实现简便高效,几乎不引入额外的计算量.本文主要针对地面反射记录进行研究,数值实验验证了该滤波算子的有效性.

In full waveform inversion, the limited acquisition aperture and nonuniform coverage of the object spectrum will affect the inversion result. In this paper,we use a tomographic filter to reduce this influence. This filter is applied to the data residuals before backpropagation as a preconditioning to the gradient,which includes the correction factor for limited acquisition aperture and nonuniform coverage and can improve the inversion result. The filter operation can be easily implemented almost without extra computation cost. This paper mainly focuses on the surface reflection data. Numerical examples showed the effectiveness of this filter operation.