Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven Aircraft

Introduction. Radar images of aircraft propellers can significantly improve the quality of their recognition and protection against simulating interference. Such images can be obtained using algorithms based on an inverse antenna aperture synthesis. A key factor determining the quality of image acqu...

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Main Authors: S. R. Heister, V. V. Kirichenko
Format: Article
Language:Russian
Published: Saint Petersburg Electrotechnical University "LETI" 2024-07-01
Series:Известия высших учебных заведений России: Радиоэлектроника
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Online Access:https://re.eltech.ru/jour/article/view/890
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author S. R. Heister
V. V. Kirichenko
author_facet S. R. Heister
V. V. Kirichenko
author_sort S. R. Heister
collection DOAJ
description Introduction. Radar images of aircraft propellers can significantly improve the quality of their recognition and protection against simulating interference. Such images can be obtained using algorithms based on an inverse antenna aperture synthesis. A key factor determining the quality of image acquisition is the accuracy of the rotor blade rotation frequency measurement. In 2019, a method for measuring the blade repetition rate was proposed, which is based on convolution of the "secondary" signal modulation spectrum while simultaneously eliminating the influence of the Doppler frequency of the signal reflected from the aircraft body. In sequential analysis, the number of cycles is determined by the ratio of the maximum blade repetition rate (hundreds of hertz) to the discrete frequency shift (thousandths of hertz). In this case, to solve the measurement problem, the required number of cycles should be hundreds of thousands, which is expensive in terms of practical implementation.Aim. Development of a two-stage method for measuring the blade repetition rate, which allows the number of signal convolution cycles to be reduced by hundreds of times.Materials and methods. The proposed method is aimed at implementing adaptation circuits to an a priori unknown rotor speed of an aircraft, which can be determined based on the blade rotation frequency. The method involves measuring the blade frequency in two stages: a rough measurement of the blade frequency rate followed by its accurate measurement within the limits of the maximum errors of the rough measurement.Results. A method for a two-stage measurement of the blade repetition rate as applied to the construction of radar images of aircraft propellers is proposed. The feasibility of the method is illustrated by the example of a signal reflected from a Mi-8 helicopter. The requirements to the measurement error of the blade repetition rate and to the frequency analysis step at the precise measurement stage are formulated. The requirement to the repetition rate of probing signals is substantiated, the fulfillment of which ensures an unambiguous restoration of the spectrum of "secondary" modulation of the signal reflected from the blades of a propeller-driven aircraft.Conclusion. The developed method for a two-stage measurement of the blade repetition rate ensures the adaptation of algorithms for constructing radar images of aircraft propellers to their rotation frequency.
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language Russian
publishDate 2024-07-01
publisher Saint Petersburg Electrotechnical University "LETI"
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series Известия высших учебных заведений России: Радиоэлектроника
spelling doaj-art-3d8ef756d0e64890bcbc27f04162ec422025-08-20T02:58:55ZrusSaint Petersburg Electrotechnical University "LETI"Известия высших учебных заведений России: Радиоэлектроника1993-89852658-47942024-07-01273688010.32603/1993-8985-2024-27-3-68-80580Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven AircraftS. R. Heister0V. V. Kirichenko1JSC "ALEVKURP"JSC "ALEVKURP"Introduction. Radar images of aircraft propellers can significantly improve the quality of their recognition and protection against simulating interference. Such images can be obtained using algorithms based on an inverse antenna aperture synthesis. A key factor determining the quality of image acquisition is the accuracy of the rotor blade rotation frequency measurement. In 2019, a method for measuring the blade repetition rate was proposed, which is based on convolution of the "secondary" signal modulation spectrum while simultaneously eliminating the influence of the Doppler frequency of the signal reflected from the aircraft body. In sequential analysis, the number of cycles is determined by the ratio of the maximum blade repetition rate (hundreds of hertz) to the discrete frequency shift (thousandths of hertz). In this case, to solve the measurement problem, the required number of cycles should be hundreds of thousands, which is expensive in terms of practical implementation.Aim. Development of a two-stage method for measuring the blade repetition rate, which allows the number of signal convolution cycles to be reduced by hundreds of times.Materials and methods. The proposed method is aimed at implementing adaptation circuits to an a priori unknown rotor speed of an aircraft, which can be determined based on the blade rotation frequency. The method involves measuring the blade frequency in two stages: a rough measurement of the blade frequency rate followed by its accurate measurement within the limits of the maximum errors of the rough measurement.Results. A method for a two-stage measurement of the blade repetition rate as applied to the construction of radar images of aircraft propellers is proposed. The feasibility of the method is illustrated by the example of a signal reflected from a Mi-8 helicopter. The requirements to the measurement error of the blade repetition rate and to the frequency analysis step at the precise measurement stage are formulated. The requirement to the repetition rate of probing signals is substantiated, the fulfillment of which ensures an unambiguous restoration of the spectrum of "secondary" modulation of the signal reflected from the blades of a propeller-driven aircraft.Conclusion. The developed method for a two-stage measurement of the blade repetition rate ensures the adaptation of algorithms for constructing radar images of aircraft propellers to their rotation frequency.https://re.eltech.ru/jour/article/view/890radar imageaircraft propellersrotor speedfrequency measurement
spellingShingle S. R. Heister
V. V. Kirichenko
Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven Aircraft
Известия высших учебных заведений России: Радиоэлектроника
radar image
aircraft propellers
rotor speed
frequency measurement
title Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven Aircraft
title_full Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven Aircraft
title_fullStr Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven Aircraft
title_full_unstemmed Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven Aircraft
title_short Method for Two-Stage Radar Measurement of the Blade Repetition Rate of a Propeller-Driven Aircraft
title_sort method for two stage radar measurement of the blade repetition rate of a propeller driven aircraft
topic radar image
aircraft propellers
rotor speed
frequency measurement
url https://re.eltech.ru/jour/article/view/890
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AT vvkirichenko methodfortwostageradarmeasurementofthebladerepetitionrateofapropellerdrivenaircraft