A fast direct imaging method for the inverse obstacle scattering problem with nonlinear point scatterers
For inverse scattering problems, this method offers a fast, FFT-based approach with improved resolution, though it is domain-specific and incremental.
The paper develops a fast direct imaging method for reconstructing the shape of extended obstacles in inverse scattering, using nonlinear point scatterers to excite high harmonic generation for enhanced resolution. Numerical experiments demonstrate effectiveness.
Consider the scattering of a time-harmonic plane wave by heterogeneous media consisting of linear or nonlinear point scatterers and extended obstacles. A generalized Foldy-Lax formulation is developed to take fully into account of the multiple scattering by the complex media. A new imaging function is proposed and an FFT-based direct imaging method is developed for the inverse obstacle scattering problem, which is to reconstruct the shape of the extended obstacles. The novel idea is to utilize the nonlinear point scatterers to excite high harmonic generation so that enhanced imaging resolution can be achieved. Numerical experiments are presented to demonstrate the effectiveness of the proposed method.