Nonlinear inversion applied to acoustic tomography

The propagation of waves through heterogeneous media is described via wave equations. For the electromagnetic case, they follow from Maxwell equations, for the acoustic case from the acoustic field equations. The fields scattering of the contrasts may be recorded and used for imaging the unknown internal structure of the object. Ideally, these imaging algorithms obey the physics as formulated via the wave equations. However, as these imaging algorithms are often computationally demanding, inverse Radon transformations based on optical ray theory may be employed. In this paper, both a approaches are tested on simulated tomo-graphic measurements. Results show that for the considered test case, phenomena such as multiple scattering and refraction should not be neglected.