A comparison of the preconditioning effects of different parameterization methods for monoparameter full waveform inversions in the Laplace domain

摘要

We examined the preconditioning effects of model parameterizations using the bulk modulus, logarithmic velocity, slowness, and sloth instead of the P-wave velocity, which is commonly used, for monoparameter acoustic full waveform inversions in the Laplace domain. Introducing the bulk modulus, logarithmic velocity, slowness, and sloth modifies the gradient direction of the velocity parameterization according to the chain rule, and these modifications function as preconditioners for the gradient direction and affect the inversion results. We compared five different parameterization methods for monoparameter Laplace-domain full waveform inversions. We also compared the results obtained using an initial velocity model that varies linearly with those obtained using a constant initial velocity model. The logarithmic velocity, slowness, and sloth parameterization methods provided better inversion results than those from the bulk modulus and velocity parameterization in the numerical examples using the Pluto and SEG/EAGE salt models. (C) 2019 Elsevier B.V. All rights reserved.