Phase instability of a signal in ionospheric propagation

Methods and results are presented pertaining to the experimental study of the phase instability of signals in short-wave ionospheric ducts. Phase instability was measured during 1970-1973 on a west-east midlatitude path, 3000 km long. Conditional probability distributions are obtained for the amplitude and rate of change of signal phase. These distributions are linked to ionospheric conditions which are systematized according to characteristic features, which makes it possible to predict the statistical characteristics of signals on the basis of predicted parameters of the ionosphere. A relationship between the rate of phase change and the instantaneous signal level is established, and rates of phase change obtained experimentally and by a theoretical Rayleigh model are compared.