In summing up the analysis carried out here, we note that for one-discontinuity paths on the order of 1000 km long at field frequencies on the order of 10 MHz the approximation of "plane" waves of (11) is suitable for describing scattering inhomogeneities with a total size not exceeding several kilometers. For disturbances of larger size it is necessary to allow for the finite curvature of the fronts of the emitted and secondary fields. If the characteristic scale of variation of the properties of the disturbance comprises a value on the order of 10 km or more, then Eqs. (15) and (16) of geometrical optics are applicable. For disturbances with characteristic scales lying in the range of 1-10 km one must allow for diffraction effects with the help of (14). Equations (11) and (14)-(16) can be used to analyze scattering on inhomogeneities of a statistical nature in the inhomogeneous ionosphere.