Application of time-reversed wave field focusing to reconstructing the frequency spectrum of background internal waves

A numerical experiment is used to analyze the possibility of focusing the time-reversed wave field for reconstructing the frequency spectrum of the vertical displacements of water layers by measuring the frequency shifts of the sound field maximum at the focal spot. The focusing of the field is controlled by varying the transmitted frequency at a fixed distribution of the reversed field, which is formed in the unperturbed waveguide, over the array aperture. The data of computations are compared with those obtained without focusing.