Spot size of the radar return from a radar-acoustic sounding system (RASS) due to atmospheric refractive turbulence

We have calculated the intensity profile on the receiving plane of a radar-acoustic sounding system (RASS) in the presence of varying amounts of atmospheric refractive turbulence. The results indicate that the refractive turbulence produces corrugations in the initially spherical acoustic wavefronts and these corrugations scatter electromagnetic energy over a large solid angle in the backward hemisphere. The net effect is to leave the scattered beamshape nearly unchanged from its form in the case of a homogeneous atmosphere. Of course the on-axis intensity is reduced considerably but the energy is scattered into such a large solid angle that this produces only an increased background level or tails in the electromagnetic intensity profile.