The determination of medium density, velocity and absorption coefficient for acoustic wave

The results of numerical solution of the inverse problem for the acoustics equations are presented. The ID distributions of medium density, velocity and absorption coefficient of acoustic waves are determined. The problem is solved within the frequency range by the optimization method. The Newton method is used as minimization algorithm. A multi-level adaptive algorithm based on a variable number of points in spatial representation of the desired values, which requires less calculations by factor of 2 or 3 as compared to a nonadaptive algorithm, is proposed. The efficiencies of a multi-level adaptive algorithm and a non-adaptive one are compared. Values of optimal constants of multi-level method are presented.