Evaluation of the effectiveness of using antennas with an asymmetric radiation pattern to reduce the influence of interference from the ground on detection with an average repetition rate in onboard pulse radars

Abstract

Problem statement. To solve the problem of warning about possible collisions of small aircraft or unmanned aerial vehicles intended for the development of hard-to-reach territories or for search and rescue operations, it is possible to use the prediction of the trajectory of aircraft using radar information about their coordinates. It is possible to increase the time of early detection of another aircraft on intersecting trajectories by reducing the level of interference from the earth's surface in a certain range of angles, which corresponds to the selected range of detection ranges. So for small aircraft, in order to avoid collisions on intersecting and catch–up courses, this is the near range area. The study is aimed at evaluating the effectiveness of radar detection using antennas with an asymmetric radiation pattern in the vertical plane. Research methods. The mathematical apparatus of the antenna array theory was actively used in the work, as well as the methodology for calculating the parameters of radar detection for airborne radars with an average pulse repetition rate. Purpose. By modeling, to evaluate the effectiveness of the effect of reducing the side lobes in a given range of angles in the plane at the angle of the place c on reducing the effect of interference from the Earth's surface on the near detection of small aircraft when the radar carrier is flying at low altitude. Results. The simulation results are presented, showing an improvement in conditions for near-range radar detection in onboard pulse-Doppler radars with an average pulse repetition rate when using antennas with an asymmetric directional function, characterized by a reduced level of lateral radiation in the lower hemisphere. Practical significance. The results of the work can be used in small-sized on-board pulse radars of low-altitude and low-speed carriers in order to increase the time of a temporary warning about the presence of other aircraft on the flight path. This task seems to be especially relevant when flying radar carriers in developed territories with difficult terrain.