ИСТИНА

Small satellite constellation can be used effectively for study Atmosphere transient phenomena, such as Terrestrial Gamma-ray Flashes (TGFs) and Transient Luminous Events (TLEs). Study of TGFs and TLEs still remains very important despite a lot of data obtained about such phenomena in recent time. The crucial point in understanding of TGFs physical nature is confirming or refuting their direct connection with the given thunderstorm or lightning. For this goal, besides of the event fine timing, a good localization of the TGF source is also necessary. The typical angular resolution of instruments usually used for TGF observations is not better than ~10o that scales to the space accuracy of TGF source localization of ~100 kilo-meters for the instruments flying at 500 km orbit. It is enough for TGF source identification with thunderstorm area, but it is insufficient to guarantee the identification with a given thunderstorm cloud. This latter task will demand an improvement of the angular resolution of suggested instruments by at least a factor of 10. The solution for the localization problem can be achieved by applying the triangulation method for observations of the selected area with different satellites. For this purpose the Universat-SOCRAT multi-satellite mission is elaborated now at Lomonosov Moscow State University. The small satellite constellation should be consisted from three basic small spacecraft, added by complementary satellites of Cubesat type. It is planned that one of them will be a joint development of Lomonosov Moscow State University and Aserbaijshan National Aviation Academy. The most of constellation satellites should be launched together with main spacecraft on similar solar-synchronous low altitude orbits (400-600 km) that provides the favourable conditions for the study of TGFs and TLEs from different areas of the Earth Atmosphere including near Equatorial and Polar regions. Such satellite constellation provides joint observations of a given area. Sufficiently light X-ray and gamma-ray detectors aimed for the TGF detection only, without spectrometer capabilities on-board the CubeSats will realize the triangulation technique. By this the necessity of maintaining of given distance between satellites is a separate technical problem. It can be solved using thrusters on nano-satellites.