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• DETERMINATION OF TARGET COORDINATE ERRORS IN MULTI-POSITION RADAR USING GROUPS OF UNMANNED AIRCRAFT

  I.V. Borisov , А.S. Kuzmenko , V. Е. Kuryan , Е. М. Levchenko , М.V. Kuryan

  273-284

  2025-07-24

  Abstract ▼

  The article proposes and develops an algebraic method for determining the coordinates of targets and their errors as part of a group of unmanned aerial vehicles. The main assumptions of the developed model of the functioning of a group of unmanned aerial vehicles: The speeds of aircraft do not exceed the speed of sound in the air, and the speeds of targets do not exceed the first space were justified. The main assumptions of the model of operation of a group of unmanned aerial vehicles: the UAV speeds do not exceed the speed of sound in the air, and the target speeds do not exceed the first space one, are justified in the article. Qualitative estimates of the radar signal reception time for a given spatial error of the target coordinates were presented. The conditions for the number of aircraft in the group are formulated, which increase the accuracy of determining the location of the target in space. The various types of errors that arise when organizing the search for targets by a group of aircraft are analyzed. The issues of dependence of the resulting error in calculating the coordinates of the search target on the error in measuring the distance between the aircraft in the group and the target itself, depending on their mutual spatial orientation, are investigated. An algorithm has been developed, calculations and analysis of the results for this task have been carried out. The simulation is based on the proposed algorithm, taking into account random coordinates of the target in a fixed sector and taking into account random errors in the measured distance between a group of aircraft and the search object. The results of modeling the influence of the configuration of a group of unmanned aerial vehicles and the location of the target on the error in determining its coordinates are presented. An assessment was carried out to determine the coordinates of the goals and an error estimate of the proposed algebraic approach. The ways of further research are determined. The issues of estimating the amount of calculation for a large number of goals are considered.
  The scope and effectiveness of the proposed algorithm and method for solving the problem as a whole are determined.

• ELECTROMAGNETIC WAVES POLARIZATION TRANSFORMATION BY PRINTED GRATINGS AT MICROWAVES

  А. О. Kasyanov

  2022-01-31

  Abstract ▼

  The problem of printed gratings application is considered as converters of electromagnetic
  waves polarization and polarizing modulators. Two directions in development of antenna engineering
  are considered in this paper. In each of them the scattering fields control of an antenna
  arrays allows essentially to expand functionalities of radio engineering sets. The first direction is
  the creation of auxiliary depolarizing reflectors for two-mirror reflector antennas and folded
  lenses. In addition, in twist-reflectors based on printed gratings, it is possible to constructively
  realize the necessary phase distributions of the field on their surfaces. Thus, it becomes possible to
  use such twist-reflectors to create phase-correcting twist-reflectors. The second direction is connected
  to application of antenna arrays for a reduction of a radar cross section of the radartracking
  targets. Transformation of a field polarization by an antenna array allows to achieve both
  these purposes. In an aspect of high cost and complexity of arrays experimental researches as a method of the analysis the mathematical simulation is selected. Besides, it is shown that introduction
  of impedance loads in the construction of the re-radiating elements of the printed grating
  opens additional possibilities for controlling the field scattered by it. Thus, twist reflectors with
  improved characteristics can be realized on the basis of microstrip-pin gratings. The given results
  can be used for choosing the most of rational electrodynamic structure geometry variant at decision
  of particular problems by antennas engineering. The possible flat arrays based on printed
  complicated shape elements application area is also discussed and it's shown these arrays are the
  very attractive type for controllable radioelectronic covers designing at microwaves. Some numerical
  results presented prove the possibility of a printed reflectarrays application as smart covers
  microwave modules.