Reconstruction of a crack with the incident waves and measurements inside a penetrable cavity

Abstract

Abstract The inverse scattering problem of determining a crack outside a known penetrable cavity from the measurements and point sources placed in a closed curve Λ inside the cavity is considered. The factorization method is used to reconstruct the crack on which the mixed-type boundary conditions are posed. To this end, we need to overcome two key difficulties. One of them is to find the relationship between the two data-to-data operators, which map the boundary data on the crack to the values of scattered fields on the closed curve Λ with outgoing radiation condition and incoming radiation condition, respectively. In addition, it is hard to decompose the near field operator in the usual way owing to the mixed-type boundary conditions. By the aid of an auxiliary operator, we can obtain the desired decomposition form in accordance with the theoretical framework of the factorization method.