Opposition Effects in Light Scattering by Regolith-Type Media

The influence of interference mechanisms on the formation of opposition effects is discussed for regolith-type media. The nonuniform structure of the electromagnetic field in the vicinity of particles plays an important role in the formation of these effects. The influence of the near field is illustrated by the example of solving the problem of the interaction of an electromagnetic wave with clusters of spherical particles. To estimate the contributions from various cooperative effects, the double-scattering approximation is used. It is demonstrated that amplitude-phase nonuniformities of the wave in the medium can suppress the effect of coherent amplification of backscattering and substantially affect the phase dependence of polarization at small phase angles.