Search

Search Results

• DIGITAL SIGNAL PROCESSING IN A PASSIVE MULTI-POSITION RADAR, CREATED ON THE BASIS OF THE UAV GROUPING

  I.I. Markovich, Е.Е. Zavtur, А.I. Panychev

  6-17

  2025-08-04

  Abstract ▼

  The expediency of creating a passive multi-position radar based on a grouping of unmanned aerial vehicles is substantiated. The variant of building of such radar is proposed, the main tech-nical problems of the sonar developing are evaluated and possible ways to overcome them are considered. It is shown that for detecting aerial targets and determining their coordinates from the radio emission of on-board equipment, the difference-rangefinder method is the most promis-ing as it does not depend on signal modulation and is potentially resistant to interference. For small-sized UAV for transmitting information over open radio channels, the typical frequency ranges are 2.4 and 5.0 GHz. A block diagram of a passive multi-position radar has been devel-oped, including digital shapers of the quadrature components of the received signal, blocks for detecting and determining the coordinates of the target. The main parameters are calculated and analytical expressions of digital signal processing algorithms for detecting and determining the coordinates of the target are given. A stroboscopic effect is used in the digital quadrature compo-nent shaper, which allows for bandpass signals to select the sampling frequency not by the upper boundary frequency of the spectrum, but by its width, which significantly reduces the requirements for the performance of the ADC and the DSP devices following it. The complex envelopes of the detected signals are generated by the method of digital generation in the time domain using digital low-frequency filters. The detection of signals is performed by an energy detector, the advantages of which are simplicity of implementation and operability in the absence of a priori information about the received signal. To determine the coordinates of the radio source, signal delays are calculated between pairs of signals received by three UAV from a multi-position radar, which are determined by the maximum modulo values of the mutual correlation functions of the signals in these pairs. It is shown that the proposed algorithms are well adapted to the processing of possible sources of radio emission on board small-sized UAV. It is established that the required perfor-mance of the radar computer for real-time operation does not exceed 84.62 GFLOPS. The design of an on-board antenna module of a passive multi-position radar in the form of a microstrip re-configurable antenna, tunable in frequency and polarization, is proposed.

• DETERMINATION OF THE COORDINATES OF RADIATION SOURCES IN PASSIVE RADARS BY THE AMPLITUDE METHOD

  V.D. Syten'kij, I.I. Markovich, Е. Е. Zavtur

  2021-04-04

  Abstract ▼

  An amplitude method for determining the radiation sources coordinates in passive radar is
  considered. An algorithm for calculating the coordinates of radiation sources in the passive mode
  of radar stations based on the reception of electromagnetic oscillations regularly damped in space
  by antennas in a collinear arrangement is synthesized. The mathematical relationships necessary
  to determine the coordinates of the target are obtained by solving the corresponding triangles
  formed by the antenna bases and the target. This made it possible to determine the location of the
  radiation source (target) by the point of intersection of the hyperbolas with the foci at the locations
  of the receiving antennas. Analytical expressions are given for determining the coordinates
  of targets in Cartesian and polar coordinate systems. The error analysis of the proposed algorithm
  was carried out taking into account the method of indirect measurements. The case of uniform
  distribution of noise over space, additively related to the signal and uncorrelated with it, is investigated.
  The formula for the root-mean-square deviation of the target range is obtained. The results
  of calculations of estimates of the absolute errors in determining the location of the radiation
  source, which depend on its location on the plane and show that the absolute error in determining
  the location of the radiation source, is minimal near the origin and increases with distance from it,
  are presented. Synthesized and investigated algorithm, due to the simplicity of the hardware implementation,
  can be used in passive location systems both independently and in addition to the
  widely used differential rangefinder method based on measuring the mutual time delays of the
  received signals.