ИСТИНА

The aim of this work is to present experimental results of the influence of electron density perturbations caused by HF-heating of ionospheric F2 layer on GNSS navigational signals at mid-latitudes. The experiments were carried out on the Sura heater near N. Novgorod, Russia with radiating frequency 4.3 MHz (during all series of experiments the plasma frequency of F2 layer was greater then the heating frequency) and effective power 40 MW and 80 MW. During the heating series with different time modulation of radiative power, the ionospheric penetration points for several navigational satellites and GNSS-receiver installed near the Sura facility crossed the heated area. For these satellites we investigated variations of total electron content (TEC), proportional to the differential carrier phase of navigational signals. It is shown that for square heating pulses, perturbations with main heating period appeared in the spectrum of TEC variations. The amplitudes of such perturbations were of the order of 0.07 TECU. These TEC oscillations support the presence of electron density irregularities caused by such modes of HF-heating in the heated region.