Incoherent backscattering of acoustic waves from surfaces with randomly distributed oscillators

A theoretical study is presented of the reflection of acoustic waves from a surface of a semi-infinite elastic medium covered by a random distribution of resonating structures. The latter are modeled by single oscillators coupled to the displacement field at the surface of the elastic medium. The incoherent part of the differential reflection coefficient of this system has been calculated using the coherent potential approximation that has been extended to account for effects of weak localization. When certain resonance conditions are satisfied, a strong enhancement of the backscattering peak has been found in the incoherent scattering of acoustic waves.