The initial stage of the interaction of high-power radio waves with the plasma of the upper ionosphere

A systematic survey is presented of the many nonlinear phenomena which arise in the initial period of the active effect of high-power radio waves on the upper ionosphere. The results of recent research conducted in order to characterize the primary phenomena and their interactions are examined, based on data collected by various methods, including the sounding of the perturbed region using probing waves of small power, the registration of the level of reflection from the ionosphere of wave pumping, and striction scattering. Experimental data is presented concerning the striction self-interaction and anomalous attenuation of the powerful wave, the appearance of rapid oscillations of its amplitude in the first seconds after the interaction, and the transfer of modulation by testing waves and foreshortened scattering by artificial inhomogeneities of small scale.