Diffraction tomography approach to acoustical imaging and media characterization

Abstract

An ultrasonics diffraction tomography method is discussed that images cylindrical inhomogeneous fluid targets located in a fluid environment. This method is based on an exact model of the interaction between a compressional plane wave and the target (multiple scattering is not neglected). First the theoretical background is summarized. Then numerical simulations illustrate the behavior of the imaging procedure. These simulations are conducted under conditions close to those of experiments that we perform concurrently. Emphasis is put on the retrieval of large but weakly refractive two-layer circular shells, into which can be inserted a high-speed core. The influence of the conditions of the image formation and the discrepancy between images derived from exact scattered pressures and Born’s approximated ones are especially investigated. Finally, procedures of reconstruction of the target’s sound velocity and attenuation are presented and discussed using synthetically generated data.