Propagation in random media--Cumulative effect of weak inhomogeneities

Abstract

The effect of weak, random inhomogeneities on wave propagation is studied. Of particular concern is the case of long distance propagation where the nature of the wave is significanfly affected by the inhomogeneities. Conventional perturbation techniques such as geometrical optics and the Born and Rytov approximations cannot be applied in this realm. The approximation technique employed is basically a selective summation technique of the type utilized in other areas of physics such as quantum electrodynamics and the theory of many-body interactions. Results are obtained for the average value and two-point correlation function of an arbitrary, initial wave. A physical interpretation of the results in terms of coherent and incoherent scattering and the classical theory of dielectrics is given. Wave statistics and the application of the results to the problem of determining the effect of the atmosphere on coherent optical communication are discussed.