Preconditioning Elastic Full Waveform Inversion by Scattering Theory

The waveform analysis is a powerful tool to investigate the physical properties in the areas of interest. Since the wave propagation is influenced by all elastic parameters, it is necessary to include these parameters in the inversion. On the other hand, multi-parameter FWI is a challenging problem because plural elastic parameters increases the dimension of the solution space, in other words desensitization of each parameter occurs due to the difference of each radiation pattern.

Some previous works used preconditioned gradient method using approximate Hessian that takes radiation pattern and geometrical spreading into account in order to compensate the desensitization. However, such methods solve many forward calculations so the computational cost becomes expensive.

In this abstract we suggest new preconditioned gradient method that seeks preconditioning operator by scattering theory obtained by Wu and Aki (1985) instead of many forward calculations.

Our study presents the new preconditioned gradient method based on scattering theory and numerical results show the effectiveness of our method.