Variations in the parameters of scattered signals and the ionosphere connected with plasma modification by high-power radio waves

We describe the results of using the incoherent scatter technique to observe time-altitude variations in regular parameters of the ionospheric plasma and wave disturbances, which accompanied periodic modification of the near-Earth plasma by radio waves emitted by the “Sura” facility. A distinctive feature of the experiments was that the processes in the ionosphere were diagnosed at a distance of about 1000 km from the facility. It was found that the spectrum composition of wave disturbances in the electron density was changing noticeably during the active experiment. Quasi-periodic processes in the ionosphere were observed with a delay of about 40–60 min. The relative amplitude of wave disturbances was equal to 0.02–0.10, and the periods were equal to 30, 60, 120, and 150–180 min. The observed effect can be explained by the generation and/or amplification of traveling ionospheric disturbances. The results of theoretical estimations agree well with the observational data.