An examination of the composite-roughness scattering model

A perturbation technique is applied to derive a composite-roughness theory for acoustic scattering from the sea surface. The leading term in the expansion obtained is the well-known result obtainable using ad hoc arguments. Higher order terms are evaluated to assess their contribution to the high-frequency monostatic backscattering strength of the sea. It is concluded that the leading term in the perturbation expansion provides an excellent approximation.