Ionosonde antenna system for combined ionospheric sounding

The article is devoted to new and promising directions of development of ionosonde antenna systems, which have appeared in recent years and are able to conduct vertical and oblique sounding of ionosphere. A brief historical overview of ionosphere research has been given. The principles of vertical sounding of ionosphere and formation of ionograms in the frequency range from 1 to 30 MHz have been considered. The most widespread ionosondes of Russia and the world (DPS-4 (USA), CADI (Canada), Parus-A, Tomion, Raduga) have been studied. The analysis of antenna systems of these ionosondes (delta antennas, large and small rhombus antennas, etc.), their designs, directional patterns, conditions of application has been carried out. Proposals for modernizing the antennas, which have been put forward by foreign and Russian scientists, have been reviewed. A proposal to create a new, original design of the antenna system for combined sounding of the ionosphere has been given. The presented results create a basis for modernization and industrial production of promising antenna arrays.