Nonlinear Ultrasound Imaging Modeled by a Westervelt Equation

We consider the ultrasound imaging problem governed by a nonlinear wave equation of Westervelt type with variable speed. show that coefficient nonlinearity can be recovered uniquely from knowledge Dirichlet-to-Neumann map. Our proof is based on second order linearization and use Gaussian beam solutions to reduce inversion weighted geodesic ray transform. propose an algorithm report results numerical implementation solve in transmission setting frequency domain.