Spectrograms 2018-2020 of multi-position facility for HF Doppler sounding

<p>This dataset contains the processed data used for the publication: MULTI-POSITION FACILITY FOR HF DOPPLER SOUNDING OF IONOSPHERIC INHOMOGENEITIES IN UKRAINE. The dataset contains the spectrograms of received signals of multi-positional Doppler sounding system for 2018-2020 years. HF signal was registered by three stations: Low Frequency Obserwatory (LFO), receiver in the southwestern part of Kharkiv (SWK), S.Y. Braude Radio Astronomical Observatory (RAO). Spectrograms plotted for 24 and 3-hour intervals.</p>