Modeling the effect of «apparent F1-layer» observed in the experiment «Radar-Progress» with the software of automatic processing of vertical sounding ionograms

This paper presents results of modeling the anomalous behaviour of F1-layer characteristics. This anomaly consisted in a step change of the /0F1-layer critical frequency and in an abnormally large /0F1 value for the season and time under consideration. The observed effect has been simulated from propagation of a large-scale traveling ionospheric disturbance. We derived quantitative values of parameters of the disturbance and analysed some peculiarities of its motion. This phenomenon was studied with the software of automatic processing of vertical sounding ionograms. Experimental data were obtained in the project «Radar-Progress».