Abstract
Simultaneous inversion of scattering and absorption attenuation is of great significance for investigating small-scale inhomogeneities and inelastic properties of the subsurface.However,applying this to complex geophysical issues is constrained by the costly computational requirements for simulations and inversions using existing methods.The coupling effects between the scattering and absorption coefficients cause parameter crosstalk artifacts in multi-parameter inversion,significantly in-creasing the nonlinearity of the inverse processes.This paper proposes a robust and effective simultaneous inversion method for scattering and absorption attenuation.The propagation of coda energy is modeled using the finite-element method based on the frequency-domain diffusion equation.We employ the truncated Gauss-Newton technique for the simultaneous estimation of scattering and absorption coefficients to decouple the two attenuation parameters during the inversion procedure.Nevertheless,the inversion may reach a local minimum if the energy frequency is inappropriate due to a phase mismatch between the simulated and measured energies.To mitigate this issue,we provide a frequency selection criterion that considers the substantial spectral shift of the energy density spectrum toward lower frequencies.Numerical examples using synthetic and experimental data indicate that our method can significantly reduce computational complexity and suppress two-parameter crosstalk without requiring a precise initial attenuation model.
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