A.R. Bestugin1, M.B. Ryzhikov2, Yu.A. Novikova3

1-3 St. Petersburg State University of Aerospace Instrument Engineering (St. Petersburg, Russia)

1 freshguap@mail.ru; 2 maxrmb@yandex.ru; 3 Nov-Jliana@yandex.ru

Problem statement. In small-sized pulse-Doppler radars for small aircraft with a small size of the antenna area, and as a result, a relatively small spatial gain coefficient, wide side lobes of the antenna directional pattern in the vertical plane, a high level of spectral components is observed for signals re-reflected from the underlying surface. In this case, the radar, which solves the problem of estimating the trajectory parameters of another small-sized, oil-reflecting object, taken for escort on a catch-up course, processes a mixture of signal, thermal noise and interference from the ground, which leads to the presence of significant direction finding errors. This article examines the requirements for setting acceptable errors in measuring the angle of inclination and ways to improve its measurement at the stage of accompaniment, not in the procedures for filtering measurement results, but through adaptive control of the parameters of the directional pattern when implementing multichannel orientation.

Research methods. Mathematical modeling is implemented on the basis of: the theory of antenna arrays with electronic scanning, the basics of monopulse direction finding and methods of tracking point-based aerial radar targets, taking into account reflections from spatially extended underlying surfaces

Purpose. To determine the criteria for the necessary measurement accuracy sufficient to perform an altitude flyby maneuver, to explore the possibilities of improving the assessment of the angle of the seat, from which information is obtained about the flight altitude of another aircraft on a catch-up course by reducing the level of side lobes in a certain range of angles, including adaptive, determined by the size of the tracking gate.

Results. An adaptive criterion has been set that must be fulfilled in order to maintain the standard deviation of the seat angle estimate, which guarantees a sufficiently accurate altitude estimate for choosing a bypass maneuver in the vertical plane when escorting another aircraft in the vertical plane. The results of reducing the standard deviation of the seat angle for different types of directional diagrams, including adaptive control of the directional diagram, are presented.

Practical significance. The results of the work can be used in the development of small-sized on-board pulse-Doppler radars for collision warning on catch-up courses.

Bestugin A.R., Ryzhikov M.B., Novikova Yu.A. Improving the effectiveness of direction finding in the vertical plane when accompanied in radar collision warning systems in the air on catch-up courses. Radiotekhnika. 2024. V. 88. № 8. P. 71−79. DOI: https://doi.org/10.18127/j00338486-202408-07 (In Russian)

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