Angle Domain Direct Envelope Inversion Method for Strong Scattering Velocity and Density Estimation

Strong scattering perturbations like large-scale salt structures in the model parameters make the task of full-waveform inversion more difficult than the weak scattering inversion. The problem becomes even tougher when both the velocity and density are taken into consideration because the tradeoff among the multiparameters further influences the inversion. In order to accomplish effective estimation for both the velocity and density with strong scatterings, we introduce an angle domain direct envelope inversion method with the new Frechet derivative. The direct envelope inversion method works well on salt structure recovery for the velocity model. However, it may not work well if the density parameter is considered. By introducing angle information into the inversion, the tradeoff between velocity and density can be greatly reduced. Numerical examples using the SEG/EAGE salt model show that by accomplishing the direct envelope inversion in the angle domain, both the velocity and density estimation with strong scattering perturbations are greatly improved, which demonstrates the validity of the proposed method.