A NOVEL TIME-DOMAIN DIRECT SAMPLING APPROACH FOR INVERSE SCATTERING PROBLEMS IN ACOUSTICS

This work is concerned with an inverse scattering problem of determining unknown scatterers from time-dependent acoustic measurements. A novel time-domain direct sampling method is developed to efficiently determine both the locations and shapes of inhomogeneous media. In particular, our approach is very easy to implement since only cheap space-time integrations are involved in the evaluation of the imaging functionals. Using the Fourier--Laplace transform, we establish an inherent connection between the time-domain and frequency-domain direct sampling methods. Furthermore, rigorous theoretical justifications and extensive numerical experiments are provided to verify the validity and feasibility of the proposed methods.