A Method for Determining the Location of a Low-Flying Air Object under Conditions of Multipath Propagation of Radio Waves

Nowadays, in large cities there is a steady tendency to increase the spatial density of telecommunication systems. The saturation of the radio spectrum with analog and digital systems used to solve the problems of radio communication and television allows improving the technologies of semi-active radar detection and determination of the coordinates of airborne objects (AO) on their basis. Radar surveillance using non-radar transmitters is often referred to as semi-active radar using extraneous or parasitic radiation sources. The advantages of such systems are minimization of deployment costs, low operating energy consumption, low probability of interference, secrecy of operation, environmental friendliness, and no requirements for the allocation of radio frequency resources. The relatively high altitudes of the antennas of communication and television transmitters with the existing radiated power create favorable conditions for detecting software moving at low altitudes. The digital signals of modern telecommunication systems have a spectrum width that provides acceptable resolution and accuracy of measuring the total range and angular coordinates. In general, systems of this type are a multi-position system consisting of one or more radiation sources and one or more receiving positions spaced in space. The paper presents a general description of the developed method for determining the location of a low-flying air object in conditions of multipath radio wave propagation using the common infrastructure of existing mobile communication networks and radar systems to ensure improved accuracy of range measurements relative to single-position radar systems. The method and its technical solution for determining the location of an unauthorized low-flying aircraft under conditions of multipath radio wave propagation and the algorithm of its functioning for the technical implementation of the proposed method are considered. Variants of determining the coordinates of air objects with different composition of primary coordinate measurements and the number of receiving positions are considered. The accuracy of determining the location of air objects for multi-position radio systems of this type under conditions of multipath radio wave propagation is estimated.