Normalization of the fluctuating component of scattered field in the far-field zone

The relationship between the geometric characteristics of the diffraction pattern at the receiving site and the parameters of ionospheric inhomogeneities is determined by the distribution of the scattered field (Ratcliff, 1956). The paper investigates the conditions that limit the possibility of using asymptotic distributions of the scattered field at finite distances from a statistically inhomogeneous medium. These conditions are important in practical studies of the electromagnetic field received by a ground-based receiver. Attention is given to justifying the assumption that the fluctuating component of a field which has passed through a chaotic screen becomes normal in the farfield region. The solution of the underlying problem is valid under two conditions: (1) statistical homogeneity of the field in the plane of the screen; and (2) existence of mixed moments of the scattered field behind the screen.