Multi-frequency iterative methods for the inverse medium scattering problems in elasticity
For researchers in inverse scattering, this work provides a numerical approach to reconstruct multiple elastic parameters, though it is an incremental extension of existing iterative methods.
The paper develops Landweber iterative methods using multi-frequency data to reconstruct Lamé parameters and density in elastic inverse scattering, demonstrating that plane pressure incident waves yield better reconstructions.
This paper concerns the reconstruction of multiple elastic parameters (Lamé parameters and density) of an inhomogeneous medium embedded in an infinite homogeneous isotropic background in $\mathbb{R}^2$. The direct scattering problem is reduced to an equivalent system on a bounded domain by introducing an exact transparent boundary condition and the wellposedness of the corresponding variational problem is established. The Fréchet differentiability of the near-field scattering map is studied with respect to the elastic parameters. Based on the multi-frequency measurement data and its phaseless term, two Landweber iterative algorithms are developed for the reconstruction of the multiple elastic parameters. Numerical examples, indicating that plane pressure incident wave is a better choice, are presented to show the validity and accuracy of our methods.