Application of Small Satellites for High Precision Measuring Effects of Radio Wave Propagation

The radio holography methodology may be applied in the scientific programs for future small satellite that will use radio signals emitted by radio navigation, radio communication satellites for precise measuring effects of radio waves propagation at low elevation angles and for global monitoring of radio communication channels passed through the atmosphere and ionosphere. Another task consists in monitoring of the wave phenomena in the atmosphere and ionosphere which may be important for telecommunication conditions in the difficult accessible regions (communications with air-planes in polar and sea zones, at small elevation angles, communications through the ionosphere between two satellites). Radio holography has been shown to provide a high angular and vertical resolution corresponding to high precision level of radio navigational radio field. For example, a weak signal reflected from the surface of the sea has been observed. As the second example a radio hologram of the ionospheric D-layer is considered. Wave structures in the concentration of the plasma with a vertical spatial period of 0.5-5 km, and variations in the electron density gradient from ±5⋅ 10 to ±8⋅ 10 electrons/(cmkm), were retrieved from analysis of the radio hologram. The features in the vertical profile of the gradient of electron density may be connected with the breaking of gravity waves in the temperature inversion region at the heights 70 80 km. Radio holography shows its effectiveness for precise measuring effects of radio wave propagation and monitoring radio channels in the ionosphere and troposphere.