Mean ray trajectories in a locally isotropic, statistically homogeneous medium

The propagation of radio waves in a locally isotropic homogeneous medium with ellipsoidal inhomogeneities is examined. The solution of the ray equations on the basis of the second approximation of geometrical optics shows that the ray trajectories diverge from the initial unperturbed trajectory because of scattering by random anisotropic inhomogeneities having a determinate orientation in the homogeneous medium. The magnitude of the divergence of the mean trajectory depends on the shape and orientation of the scattering inhomogeneities as well as on the wave-propagation distance in the medium.