Analysis of Acoustical Scattering from a Small Sphere Placed Close to an Interface

Features of Rayleigh scattering from a spherical object located near a planar rigid boundary at distances smaller than the wavelength are revealed. The expansion in terms of the wave parameter reduces a scattering problem to a sequence of potential problems. The need to describe the effects associated with the normal to the boundary components of vibrational velocity of the particle and the radiation pressure force necessitates taking into account the corrections to the results obtained earlier in the lowest order of expansion. The generalized optical theorem is used to find the imaginary correction to the scattering amplitude that takes into account the effects of the bounding surface.