RADIO PHYSICS AND RADIO ASTRONOMY

Subject and Purpose. The authors recently proposed a passive radar method for determining ranges and coordinates of surface targets using a single reference receiving point. The work is directed at further developing this method with a focus on scenarios where the surface target incorporates a radar with a rotating radiation antenna, such as a pulse omnidirectional radar.

Methods and Methodology. The previously proposed passive radar method for determining the distance to a target is extended to the case where a surface object can have a rotating radiation antenna. Still, the method is based on using a radio buoy, which creates a supplementary radio wave propagation path. The receiving device is installed on the shore and detects two signals. One is the radio buoy signal travelling the supplementary propagation path. The other is the target direct signal
travelling the primary path. The time delay between the two signal arrivals is measured, and the distance to the target is calculated using a specially developed algorithm. The system operation is analyzed and evaluated.

Results. The previously proposed passive radar method for determining the target distance employs a radio buoy equipped with a transmitter and an amplifier-repeater. The method has been refined enough to range targets carrying rotating radiation antennas. As before, an additional radio wave propagation path from the target to the amplifier-repeater arises and is caught by the ground-based receiver on the shore. The task of determining the time delay between the radio beacon signal and the main signal from the target faces challenges associated with the movement of the target’s rotating antenna. The challenges can be effectively managed through a technique that is presented in the paper and expertly addresses the time delay between signals
traveling along the primary and supplementary paths, as detailed in the paper. For practical implementation, the proposed principle of passive radar operation is supported by a surface target ranging algorithm.

Conclusions. A method has been proposed for constructing a passive radar system that can measure the distance to a target carrying a rotating radiation antenna. Among other innovations, it was suggested to equip the radio buoy with an amplifier-repeater. To implement the method developed, a functional diagram of a rangefinder for surface objects was introduced.

Keywords: passive radar, rotating radiation antenna, radio buoy, amplifier-repeater

Manuscript submitted  02.06.2025

Radio phys. radio astron. 2025, 30(4): 268-275

REFERENCES

1. Skolnik, M.I. ed., 1990. Radar handbook. 2nd ed. Publisher. McGraw-Hill Professional. ISBN 0-07-057913-X

2. Howland, P.E., 1994. A Passive Metric Radar Using the Transmitters of Opportunity. In: 1994 Int. Conf. on Radar: proc. Paris, France, May 1994, pp. 251—256.

3. Nordwall, B.D., 1998. Silent Sentry A New Type of Radar. Aviat. Week Space Technol., 30, pp. 70—71.

4. Meyer, M.G., and Sahr, J.D., 2003. Passive coherent scatter radar interferometer implementation, observations, and analysis. Radio Sci., 39(3). DOI: 10.1029/2003RS002985

5. Willis, N., 2004. Bistatic Radar. 2nd ed. SciTech Publishing, Institution of Engineering and Technology. 329 p. ISBN 1-891121-45-6

6. Willis, N.J., Griffiths, H.D., and Davis, M.E., 2007. Advances in Bistatic Radar. Institution of Engineering and Technology. 494 p. ISBN 978-1-891121-48-7.

7. Besedin, O.M., Zelenskiy, О.О., Kulemin, G.P., Lukin, V.V., 2005. Processing of random signals and processes. National aerospace university "KhAI", Kharkiv, 2005. 469 p.

8. Mytsenko, I.M., Roenko, O.M., 2023. Environmentally safe over-the-horizon radar of the meter range for the protection of territorial waters. Radio Phys. Radio Astron., 28(4), pp. 287—295. DOI: 10.15407/rpra28.04.287

9. Mytsenko I.M., Roenko O.M.,2025. Determining the distance to the target during passive radar detection of surface objects. Radio Phys. Radio Astron., 30(2), pp. 101—108. DOI: 10.15407/rpra30.02.101

10. Van Trees, H.L., 2001. Detection, Estimation, and Modulation Theory. Part I: Detection, Estimation, and Linear Modulation Theory. Copyright 2001 John Wiley & Sons, Inc., ISBNs: 0-471-09517-6 (Paperback); 0-471-22108-2 (Electronic).

11. Spectrum and Signal Analyzers /Selection Guide. Keysight Technologies, 2014. Publishedin USA, September 30, 2014, 5968-3413RURU. Available from: https://www.testunlimited.com/pdf/an/keysight_N9010A_selection%20guide.pdf

12. Curry, G.R., 2005. Radar System Performance Modeling, ISBN 978-1-58053-816-9, S.168.