The reflexion of radio waves from a stratified ionosphere modified by weak irregularities. II

The results of an earlier paper are applied to an ionosphere containing weak random irregularities, specified only statistically. It is supposed that the shape of the irregularities is described by a Gaussian autocorrelation function, and that their intensity varies in a known way with height. Possibilities of obtaining slow and rapid fading characteristics from forward and back scatter by the irregularities are considered briefly. Certain conclusions of the earlier paper, concerning the importance of scattering by irregularities near the reflexion level, are modified. A mechanism for explaining the occurrence of ‘spread F ´ signals is suggested.