IONOSPHERIC COMMUNICATION USING ARTIFICIAL IONIZED INHOMOGENEITY

Abstract

The article investigates the use of artificial ionized inhomogeneity in ionospheric communication. The range of 1.5 … 30 MHz used in military systems of shortwave radio and ionospheric communication has been analyzed. The paper proposes a new method of ionospheric communication, in which the existing shortcomings of ionospheric communication are largely eliminated. The phenomenon of artificial ionized inhomogeneity in a medium with large-scale artificial inhomogeneities of the permittivity is described. The paper presents a scheme for the formation of a coverage zone from an artificial ionized inhomogeneity. Promising ways of developing radio reconnaissance, electronic suppression, locati on and communications based on the process of nonlinear interaction of powerful electromagnetic radiation in the VHF range with the Earth's ionosphere are noted. Nonlinear interaction of fields in the ionosphere arises under the condition that the magnitud e of the incident electromagnetic field exceeds the level of the natural field of the ionospheric plasma, due to the thermal motio n of charged particles. This happens at VHF power levels of several tens ... hundreds of kW. The emergence of an artificial ionized inhomogeneity under the influence of a powerful radio wave field belongs to the category of essentially nonlinear ionospheric effects, in which the energy of an electromagnetic wave, due to the presence of collisions between electrons, ion s, and neutral molecules, is converted into the energy of motion of these particles. With an increase in the power of the incident electromagnetic wave, a qualitative jump occurs in the structure of the artificial ionized inhomogeneity. A non-stationary inhomogeneous structure is formed, consisting of inhomogeneities elongated along the geomagnetic field with different transverse dimensions. The transverse dimensions of large-scale inhomogeneities range from 50 ... 100 m to 1 ... 10 km. Longitudinal dimensions exceed transverse dimensions by tens of times. Small-scale inhomogeneities have transverse dimensions less than the length of the perturbing wave and amount to 1 ... 30 m. The longitudinal dimensions of these inhomogeneities exceed the transverse dimensions by hundreds ... thousands of times. A feature of small-scale artificial ionized inhomogeneity is their ability to intensively scatter VHF. Since the height of an artificial ionized inhomogeneity can reach ~200 km and higher above the Earth's surface, it is possible to use artificial ionized inhomogeneity for long-range over-the-horizon communications. Signals scattered by an artificial ionized inhomogeneity can be received on the Earth's surface only by those receiver s that are located within the region extended in the magnetic latitude direction. The length and width of the zone on the Earth's surface depend on geomagnetic, radiophysical and other factors. The article calculates the level of radiated power of the source, at which an artificial ionized inhomogeneity is formed. The radiated power of the source is determined, at which the nonlinear ionospheric effect begins to play a role.