3D acoustic waveform inversion in the Laplace domain using an iterative solver

초록

In this paper we propose a 3D acoustic full waveform inversion algorithm in the Laplace domain. The partial differential equation for the 3D acoustic wave equation in the Laplace domain is reformulated as a linear system of algebraic equations using the finite element method and the resulting linear system is solved by a preconditioned conjugate gradient method. In the Laplace-domain waveform inversionthe logarithm of the Laplace transformed wavefields mainly contain long-wavelength information about the underlying velocity model. As a resultthe algorithm smoothes small-scale structure but roughly identifies large-scale features within a certain depth determined by the range of offsets and Laplace damping constants employed. Our algorithm thus provides a useful complementary process to time- or frequency- domain waveform inversionwhich cannot recover large- scale structure when low-frequency signals are weak or absent. The algorithm is demonstrated on a synthetic example: the SEG/EAGE 3D salt-dome model. © 2010 Society of Exploration Geophysicists.