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Determining the influence of the underlying surface on the propagation of an electromagnetic wave of the UHF and SHF bands plays a crucial role in the design of the radio communications, radar, television and mobile stations. In the work a new method for determining the influence of the earth surface has been considered taking into account the reflection from the earth surface, scattering and absorption of radio waves in the earth atmosphere. The reflection coefficient, the propagation factor of the radio wave, the potential of the radio communication and location station have been calculated. It has been shown that to ensure the smallest influence of the reflecting surface on the propagation distance of radio waves, it is necessary to arrange the parts of the radio communication (location) system at the Brewster angle, since the modulus of the reflection coefficient of the electromagnetic wave from the surface is minimal. It has been determined that the strong irregularity of the underlying surface also minimizes its effect on the potential characteristics of the devices being developed. It has been explained that this is due to the defocusing of the reflected electromagnetic wave and a decrease in its amplitude at the receiving end of the system. The results obtained are of interest for optimization of the parameters of the developed radio communication and location systems, as well as during the laying of the radio communication route.

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Unsanctioned intrusion of unmanned aerial vehicle (UAV) on the territory of the guarded object is primarily detected by specialized radio surveillance systems. The results obtained by radio surveillance systems are used for aiming of UAV visual identification and radio jamming systems. In this work, the problems of UAV detection and tracking of the target trajectory are considered. The known tracking filter systems for radio surveillance application were analyzed and a specialized matrix tracking filter system was proposed, which uses in its algorithm a dynamically changing energy potential of the radio surveillance system. The developed tracking filter system efficiency is evaluated using methods of matrix calculation, mathematical modeling, and probability theory. It has been established that the developed tracking filter system lets the radio surveillance equipment most effectively initiate trajectories of UAV, set its movement window, consider radio surveillance equipment characteristics, and approximate the trajectory of UAV at times of missed detections connected to radar cross-section fluctuations of moving targets. A high efficiency of the developed system has been achieved by decreasing the inaccuracy of the target position prediction two times in comparison with the known tracking filter systems. The obtained results allow easy scaling of the developed tracking filter system for its application as a part of any radio surveillance system.

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