The network for monitoring the high-latitude ionosphere by the method of oblique ionospheric sounding deployed in the Russian Arctic region is considered. The study describes the main results of operational data processing for studying the high-latitude ionosphere and determining the conditions for the optimum operation of radio communication systems and over-the-horizon radars in this region. The study demonstrates the potential of the network as a tool for the remote diagnostics of parameters of small-scale artificial ionospheric irregularities induced by powerful HF radio waves in the mid-latitude ionospheric F-region.

The results of long-term studies of the effects of the high-latitude ionosphere modification by powerful high-frequency (HF) radio waves generated by the EISCAT/Heating facility based on remote diagnostic methods are presented. The brief description of remote diagnostic instruments and methods is given. The excitation conditions and characteristics of small-scale artificial field-aligned irregularities induced by the O- and X-mode HF pumping are considered using the bi-static scatter method. The results of the spectral analysis of HF heater signals under various radiation modes are provided. It is shown that the X-mode HF pumping induces narrowband artificial radio emission of the ionosphere recorded at a distance of more than 1000 km from the heater.