RU2732505C1 - Method for detection and azimuth direction finding of ground-based radio-frequency sources from a flight-lifting means - Google Patents

Abstract

FIELD: radio equipment.SUBSTANCE: invention relates to radio engineering and can be used in multichannel monopulse detectors-direction finders (DDF) of radio monitoring systems for determination of azimuth and elevation angle to radio emission source (RES) from flight-lifting means (FLM). Technical result is achieved by using navigation information on antenna array (AA) angles and converting non-direction-finding results, and the direction characteristics AA of the associated moving coordinate system (CS) in the fixed CS associated with the Earth. This makes it possible to carry out direction finding and search for azimuth on RES in curvilinear cut of two-dimensional azimuth-elevation direction-finding relief, corresponding to evolution of orientation of direction vector of arrival of radio wave in azimuthal circle at arbitrary orientation AA, arranged on FLM. Due to such accounting of information on FLM orientation, higher accuracy and reliability of direction finding of ground-based RESs. Besides, according to the proposed method, the "reliability" evaluation of direction-finding RES provides the required selection of direction-finding results by reliability factor with increase in accuracy and reliability of direction finding of RES with FLM in real conditions. Method takes into account the presence of inter-channel correlation of received spectral components of radio signals, caused by presence in real conditions of external interference, is operable under conditions of a priori unknown interference intensity in different spatial receiving channels.EFFECT: high efficiency of azimuth direction finding of ground-based RESs with arbitrarily oriented FLM.1 cl, 6 dwg

Description

The invention relates to radio engineering and can be used in multichannel monopulse detectors-direction finders (OP) of radio monitoring systems for determining the azimuth and elevation angle to the radio emission source (RRI) from the flight-lifting device (LPS).

To increase the range and expand the working area of radio monitoring of ground-based RES, the detector-direction finder is placed on board the LPS as a target load. In this case, it is possible to use volumetric antenna arrays (AR), which provide indicators of accuracy and reliability of direction finding that are close in azimuth and elevation. At the same time, the OP must ensure the fulfillment of the requirements not only for the main technical purpose (including the accuracy and reliability of the direction finding of the IRI), but also in terms of restrictions on the weight and overall characteristics that affect the flight performance of the LPS.

In particular, as one of the options for a three-dimensional AR, the structure of which ensures the minimization of the number of used radio receiving channels of the OP and receiving antenna elements, a helical antenna array, considered in [Artemov ML, Afanasyev OV, Slichenko M. P., Artemova E.S. Method for two-dimensional monopulse direction finding of radio emission sources. RF patent No. 2696095, G01S 5/04].

However, in the practice of radio monitoring, situations are possible when the ratio of the flight altitude of the LPS to the range to the IRI is much less than one (radio monitoring of the IRR at ranges to the LPS close to the radio horizon). In such cases, only the azimuth is an informative indicator of the spatial position of the ground-based IRI, and the implementation of the AA of a volumetric structure seems to be inexpedient, therefore, in these situations, flat AAs are widely used in practice. Due to the flat structure, it is possible to meet the requirements in terms of flight performance characteristics of the LPS.

For plane AAs, the accuracy and reliability of direction finding significantly deteriorate when the angle of the direction of arrival of the radio wave tends to zero in the vertical plane (perpendicular to the plane of the antenna elements of the antenna), which is due to a decrease in the AA aperture in the projection onto the plane of the wavefront of the radio wave.

It is important to take into account the change in the angles of the spatial orientation of the LPS during its movement. The plane of the location of the AA elements changes orientation in space in accordance with the parameters of the LRS movement, and the characteristics of the accuracy and reliability of the direction finding of the AIR depend on the current angles of the LRS orientation. Consequently, for the direction finding of AIR with LPS, it is necessary to ensure reception of a radio wave in the general case with a nonzero angle relative to the plane of the AR, which depends both on the relative position of the AIR and AR and on the angles of the carrier's spatial orientation.

The results of estimating the direction to the IRI are used to determine the coordinates of the IRI by a triangulation method. Since the coordinates of the IRI are determined in a fixed coordinate system (CS) associated with the earth (for most problems - in the Gauss-Kruger topographic projection), then the estimates of the direction angles on the IRI must be determined in this CS. The estimate of the direction vector to the IRR obtained in the SC associated with the LPS, using information about the current angles of the orientation of the LPS, is converted into a stationary SC connected to the ground. In the case of direction finding in the azimuthal-elevation plane, the conversion of the direction to the IRI into a ground-connected SC assumes the use of a standard procedure for rotating a three-dimensional unit vector along three Euler-Kolmogorov angles [GOST 20058-80. Aircraft dynamics in the atmosphere. Terms, definitions and designations. M., 1981. No. 3913, 52 p. (Standards Publishing House)]: roll, pitch and yaw (course). The use of these three LPS orientation angles allows to unambiguously transform the results of azimuthal-elevation direction finding between different CS.

If the information about the LPS orientation is ignored, additional direction finding errors arise, with an increase in the ratio of the AA aperture to the radio wavelength, the probability of anomalous direction finding error increases, which leads not only to a decrease in the accuracy and reliability of direction finding, but also to a decrease in the operating frequency range of the OP (the AA overlap coefficient in frequency).

Known methods for determining the coordinates of the IRI, taking into account the orientation of the LPS in space.

There is a known method for determining the values of the azimuth and elevation angle of IRI from the LPS board, which provides an increase in the accuracy of finding the location of IRI by more fully taking into account the spatial orientation of the antenna array of the meter, presented in [Naumov A.S., Elizarov V.V. Determination of the coordinates of the radio emission source during direction finding from the LPS. - The successes of modern radio electronics, 2015, No. 7, p.56-61], which consists in:

запоминают и используют для расчетов результатов измерений;1. Measuring the orientation of the direction finder antenna system relative to the LPS body (roll, pitch, heading). The values

memorize and use for calculating measurement results;

в процессе полета ЛПС;2. Search and reception of signals of radiation sources in a given frequency band

during the flight of the LPS;

и угла места

в системе координат антенной системы;3. Measurement of spatial coordinates of IRI: azimuth

and elevation

in the coordinate system of the antenna system;

, где

– широта ЛПС,

– долгота ЛПС,

– высота ЛПС;4. Determining the location of the LPS using GNSS

where

- LPS latitude,

- LPS longitude,

- LPS height;

5. Conversion of LPS coordinates into a geocentric coordinate system:

;

;

в декартовую систему координат:6. Translation of the direction vector to the source

to a Cartesian coordinate system:

;

;

на три соответствующие углам Эйлера матрицы поворота:7. Sequential multiplication of the original vector

by three rotation matrices corresponding to the Euler angles:

,

,

Where

,

,

;

,

,

;

с целью учета ориентации ЛПС относительно земной поверхности и положения ЛПС в пространстве, в результате чего получают направления на ИРИ

;8. Conversion of the corrected direction vector to the IRI

in order to take into account the orientation of the LPS relative to the earth's surface and the position of the LPS in space, as a result of which directions to the IRI

;

на матрицы поворота относительно каждой из трех осей:9. Serial multiplication of a vector

on rotation matrices about each of the three axes:

;

;

и угла места по формулам:10. Determining the azimuth value

and the elevation angle by the formulas:

,

,

.

...

A known method of locating ground IRI from the LPS, presented in [Berezin A. V., Bogdanov Y. N., Vassenkov A. V., Vinogradov A. D., Dmitriev I. S., Popov S. A. A method for determining the coordinates of a ground source of radio emission during radio direction finding from an aircraft. RF patent №2610150, G01S 1/08 ] and consisting in:

1. Reception of radio signals by the airborne direction finding antenna (BPA);

2. Frequency selection of radio signals;

3. Determination of radio bearing lines in the azimuth plane of the UAV;

4. Registration of the received data periodically by counts;

5. Formation of at least one independent pair of intersecting half-planes of the position of the ground IRI, orthogonal to the azimuthal plane of the FUA, passing through each received line of the direction finder;

6. Selection and weight processing of pairs of independent data samples, taking into account the dependences of the variances of estimates of coordinates of the ground-based IRI on the relative position in space of the LPS and ground-based IRI. In the selection and weight processing of pairs of independent data samples, the dependences of the variances of the estimates of the coordinates of the ground-based IRR on the parameters of the angular orientation of the FUA and on the angles of intersection of the position line and normals to the half-planes of the position of the ground IRR with the Earth's surface were additionally taken into account

7. Formation of normals to the half-planes of the position of the ground IRI;

8. Determination of at least one line of the position of the ground IRI as the line of intersection of an independent pair of intersecting half-planes of the position of the ground IRI, the parameters of which are determined from the condition of orthogonality to the aforementioned normals;

9. Determining the coordinates of the ground-based IRI as the point of intersection of the line of position of the unearthly IRI with the Earth's surface using an iterative procedure for its search.

Also known is a method for determining the coordinates of IRI [Zhitnik MA, Strocev AA, Suhenkiy IA, Method for determining the coordinates of a radio emission source from an aircraft on two azimuthal bearings. RF patent No. 2638177, G01S 1/08 ], which consists in

1. Reception of radio signals by the onboard direction finding antenna;

2. Frequency selection;

3. Determination of the bearing line in the plane of the direction-finding antenna;

4. Weight processing of the received data;

5. Formation of auxiliary planes according to the results of weight processing, orthogonal to the plane of the direction-finding plane of the direction-finding antenna and passing through each received line of bearing. At the moments of receiving bearings, the LPS coordinates are converted into a geocentric rectangular coordinate system, then a transition matrix is made from the associated coordinate system to a normal moving coordinate system and then to a geocentric rectangular coordinate system by multiplying the rotation matrices by the angles of roll, pitch and yaw of the associated coordinate system;

6. Finding a straight line of intersection of two auxiliary planes;

7. Calculation of the coordinates of the IRI as the point of intersection of the found straight line and the Earth's surface described by the ellipsoid.

The main disadvantage of the above methods is the use of information on elevation bearings in determining the coordinates of the IRI, which are measured with low (compared to azimuths) indicators of accuracy and reliability due to the insufficient resolution of the AR at small true elevation bearings to the ground IRI. In this case, information about the orientation of the LPS in space is used to transform the direction finding results, and not the radio signals received during the direction finding, which, in the case of azimuthal direction finding of ground-based ERS, leads to a decrease in the accuracy and reliability of direction finding.

The known method of amplitude two-dimensional direction finding [Ufaev VA, Volobuev MF, Mikhailenko SB, Volkov AA. Amplitude two-dimensional direction finding method. RF patent No. 260130, G01S 5/04 ], which involves the conversion of the received signal amplitudes into an angular spectrum and determining the direction to the emitter at its maximum. The analog can be used in ground and aviation radio systems for all-aspect determination of the direction to radiation sources.

This method involves the following procedures:

1. Reception of the radiated signal using identical multidirectional antennas.

) представляет собой:2. Measurement of the amplitude of the received signals. The value of the radio signal of the nth antenna (

) represents:

,

,

– азимут и угол места, соответственно, направления на ИРИ.

- azimuth and elevation, respectively, of the direction to the IRI.

3. Convert measurements to angular spectrum

.

...

4. Determination of the direction to the emitter by maximizing the angular spectrum:

.

...

The main disadvantages of the method are as follows:

1. When forming the decisive statistics, the spatial orientation of the LPS is not taken into account: roll, pitch, yaw (course).

2. Low accuracy of direction finding of the ground-based IRI in elevation, when the ratio of the flight altitude of the LPS to the range to the IRI is much less than one (radio monitoring of the SAR at ranges to the LPS close to the radio horizon), which is a limitation of the applicability of this method in practice.

способа справедлива в случае амплитудного двухмерного пеленгования, когда антенны обнаружителя-пеленгатора являются идентичными и разнонаправленными, расположены в пределах небольшой области пространства, которая относительно удаленного излучателя является точечной. В общем случае при наличии взаимных влияний в антенной системе обнаружителя-пеленгатора, а также в случае использования ненаправленных антенных элементов выражение (2) для решающей статистики становится несправедливым, что приводит к ухудшению показателей эффективности способа.3. Decisive statistics

The method is valid in the case of amplitude two-dimensional direction finding, when the antennas of the detector-direction finder are identical and multidirectional, located within a small region of space, which is a point relative to the distant radiator. In the general case, in the presence of mutual influences in the antenna system of the detector-direction finder, as well as in the case of using non-directional antenna elements, expression (2) for the decisive statistics becomes unfair, which leads to a deterioration in the efficiency indicators of the method.

4. Expression (2) for the decisive statistics of detection does not take into account the presence of inter-channel correlation of spectral samples of time realizations due to the presence of external interference in real conditions of receiving radio signals.

The closest in technical essence to the proposed is the method of azimuthal direction finding of ground sources of radio emission, presented in [Artemova ES, Slichenko M.P. Azimuthal direction finding of ground-based sources of radio emission when placing a flat antenna array of arbitrary configuration on an aircraft. - Antennas, 2019, No. 3, p.53-61], taken as a prototype.

The prototype method includes the following procedures.

1. Multiple, sequential in time, synchronous reception of signals in the time domain (simultaneously falling into the current reception and analysis band) from the outputs of all antenna arrays in the spatial channels of the OP, synchronous transfer to a lower frequency, synchronous conversion of signals in the time domain into digital form, calculation of fast Fourier transform samples of each digitized realization in each spatial channel of the detector-direction finder.

взаимных энергий, равной произведению

накопленной матрицы

взаимных энергий и матрицы

, обратной к матрице корреляции

аддитивного шума.2. For each spectral report, the calculation of channel and mutual (interchannel) energies of the fast Fourier transform and the accumulation of energies by summing their values calculated for each received signal, and the formation of a matrix

mutual energies equal to the product

accumulated matrix

mutual energies and matrices

inverse to the correlation matrix

additive noise.

– матрица взаимных энергий сигналов, «накопленная» по серии из K>1 измерений, с элементами

- a matrix of mutual signal energies "accumulated" over a series of K > 1 measurements, with elements

представляет собой сумму комплексных амплитуд радиосигнала ИРИ и шума:The value of the complex amplitude of the spectral component of the Fourier transform of the received radio signal at the output of the n-th antenna,

is the sum of the complex amplitudes of the SIR radio signal and noise:

– комплексная амплитуда радиосигнала;Where

- complex amplitude of the radio signal;

– соответственно азимут и угол места направления на источник излучения;

- respectively azimuth and elevation angle of direction to the radiation source;

– вектор аддитивного шума.

Is the vector of additive noise.

– комплексный отсчет (с порядковым номером nb =0…Nb-1) быстрого преобразования Фурье k-ого сигнала принятого в

-м пространственном канале обнаружителя-пеленгатора (совпадающий с номером антенны АР, подключенной ко входу канала);

- complex sample (with serial number nb = 0 ... Nb-1) fast Fourier transform of the kth signal received in

-th spatial channel of the direction finder detector (coinciding with the number of the AP antenna connected to the channel input);

1…N – порядковые номера пространственных каналов обнаружителя-пеленгатора;

1 ... N - serial numbers of the spatial channels of the detector-direction finder;

k = 1 ... K is the sequence number of the received signal in the time domain;

– матрица корреляции аддитивного шума (при отсутствии корреляции шума матрица является диагональной);

- matrix of correlation of additive noise (in the absence of correlation of noise, the matrix is diagonal);

– оператор эрмитова сопряжения,

- Hermitian conjugation operator,

– обратная матрица,

- inverse matrix,

– оператор следа матрицы.

- matrix trace operator.

направления на ИРИ в земной СК по измеренным навигационным параметрам ЛПС:3. Formation of a unit vector

directions to the IRR in the terrestrial SC according to the measured LPS navigation parameters:

, (2)

, (2)

,

,

– матрица вращения ЛПС в трехмерном евклидовом пространстве [ГОСТ 20058-80. Динамика летательных аппаратов в атмосфере. Термины, определения и обозначения. М., 1981. № 3913, 52 с. (Издательство стандартов)], зависящая от углов пространственной ориентации: φ – угол крена, θ – угол тангажа, ψ – угол рысканья; Where

- LPS rotation matrix in three-dimensional Euclidean space [GOST 20058-80. Aircraft dynamics in the atmosphere. Terms, definitions and designations. M., 1981. No. 3913, 52 p. (Standards Publishing House)], depending on the angles of spatial orientation: φ - roll angle, θ - pitch angle, ψ - yaw angle;

имеет вид:Vector

looks like:

,

,

для каждого обнаруженного сигнала на частоте

в земной СК, зависящей от ориентации ЛПС в пространстве.4. Formation of a one-dimensional vector complex radiation pattern (VKDN) of AR with an arbitrary structure and directivity characteristics of antenna elements

for each detected signal at frequency

in the terrestrial SC, depending on the orientation of the LPS in space.

In the particular case of a flat annular equidistant antenna array

,

,

; n, N - serial number and number of AE,

;

f is the frequency of the EM wave, MHz;

– оператор эрмитово сопряжения.

- operator of Hermitian conjugation.

с различных азимутальных направлений в земной СК, с учетом межканальной корреляции спектральных отсчетов сигнала по формуле:5. Measurement of bearing relief (DF) values for each i-th detected signal at a frequency

from different azimuthal directions in the terrestrial SC, taking into account the interchannel correlation of spectral samples of the signal according to the formula:

– ВКДН АР ОП в земной СК, зависящая от истинного азимута на ИРИ и трех углов ориентации ЛПС.

- VKDN AR OP in the terrestrial SC, depending on the true azimuth to the IRI and three angles of orientation of the LPS.

для каждого i-го обнаруженного сигнала на частоте

по возможным азимутальным направлениям прихода радиоволны6. Calculation of the maximum PR value

for each i-th detected signal at frequency

along the possible azimuth directions of radio wave arrival

по формуле7. Estimation of the direction of arrival of the radio wave for each i-th detected signal at the frequency

according to the formula

The main disadvantages of the prototype method are as follows.

1. The real conditions of the OP functioning are characterized by a saturated highly dynamic electromagnetic environment, caused, among other things, by the congestion and saturation of the radio-frequency spectrum formed by the radiation of many radio-electronic means. When the OP operates in such conditions, in practice, cases are possible when the received signal is formed both by a direct radio wave from the IRR and by a reflected radio wave from re-emitting elements located in the receiving region. In particular, when placing an AR OP on the surface of the fuselage of an air carrier or as an attached target load, re-emitting objects can be both structural elements of the carrier (for example, landing gear), and standard avionics located on the outer surface of the carrier. In addition, the saturation and congestion of the radio frequency spectrum can lead to cases of receiving radio signals with mutually overlapping spectra from several SIRs. Proposed in the prototype method, single-signal bearing of several frequency-inseparable radio signals in most cases will lead to abnormal bearing errors. Therefore, the designated reception conditions necessitate the implementation of procedures for detecting the spectral components of signals, identifying them by belonging to the same IRI, as well as assessing the "reliability" of the direction finding of IRI in a saturated electromagnetic environment. The implementation of these procedures in the prototype is not provided, which is a disadvantage, since it leads to a decrease in the performance indicators of the radio monitoring systems when determining the azimuth and elevation angle on the ERS with LPS in a real saturated electromagnetic environment.

2. During the flight, the carrier for various reasons performs air maneuvers, including a turn, in the course of which the direction finding results may be unreliable due to significant changes in the orientation angles of the aircraft, leading to the reception of radio signals outside the working sector of the angles. However, the prototype does not provide for an assessment of the "reliability" of the direction finding of the IRI, which is a disadvantage. The implementation of this assessment will provide the necessary selection of direction finding results in terms of reliability with an increase in the accuracy and reliability of direction finding for IRI with LPS in real conditions.

предполагается известной. Однако в большинстве практических ситуаций матрицу

можно считать известной лишь с точностью до некоторого скалярного множителя, характеризующего априорно неизвестную интенсивность помех в различных пространственных каналах приема. Используемое в способе-прототипе предположение об известной матрице ковариации является недостатком, существенным образом ограничивающим область применимости и показатели работоспособности в реальных условиях.3. The prototype takes into account the presence of interchannel correlation of the received spectral components of radio signals due to the presence of external interference in real conditions, while the covariance matrix

supposed to be known. However, in most practical situations, the matrix

can be considered known only up to a certain scalar factor characterizing the a priori unknown intensity of interference in various spatial reception channels. Used in the prototype method, the assumption of the known covariance matrix is a disadvantage that significantly limits the scope and performance indicators in real conditions.

The indicated disadvantages of the prototype method cause a decrease in the performance indicators of its functioning when implemented in radio monitoring systems to determine the azimuth and elevation angle to ground-based ERS with LPS in real conditions of a saturated highly dynamic electromagnetic environment.

The problem to be solved by the proposed technical solution is to increase the efficiency of azimuth direction finding of ground-based radiation sources from the LPS of multi-channel monopulse detectors-direction finders.

взаимных энергий, равной произведению

накопленной матрицы

взаимных энергий сигналов по серии из K>1 измерений и матрицы

, обратной к матрице корреляции

аддитивного шума, формирование единичного вектора

направления на ИРИ в земной системе координат (СК) по измеренным навигационным параметрам ЛПС, формирование одномерной векторной комплексной диаграммы направленности АР с произвольными структурой и характеристиками направленности антенных элементов (

) для каждого обнаруженного сигнала на частоте

в земной СК, зависящей от ориентации ЛПС в пространстве, измерение значений пеленгационного рельефа (ПР) для каждого i-го обнаруженного сигнала на частоте

с различных азимутальных направлений в земной СК, с учетом межканальной корреляции спектральных отсчетов сигнала, вычисление максимального значения ПР

(φ – угол крена, θ – угол тангажа, ψ – угол рысканья); для каждого i-го обнаруженного сигнала на частоте

по возможным азимутальным направлениям прихода радиоволны, оценка направления прихода радиоволны для каждого i-го обнаруженного сигнала на частоте

, согласно изобретению , выполняют процедуры адаптивного к неизвестной интенсивности шума обнаружения спектральных компонент сигналов и их отождествления по принадлежности к одному и тому же ИРИ, вычисляют значения адаптивного к неизвестной интенсивности шума ПР для каждого i-го обнаруженного сигнала на частоте

с различных азимутальных направлений в земной СК, с учетом межканальной корреляции спектральных отсчетов сигнала по формуле:To solve the problem in the method of detecting and azimuthal direction finding of ground-based sources of radio emission (IRS) from a flight-lifting facility (LPS), including multiple time-sequential synchronous reception of signals in the time domain, simultaneously falling into the current reception band and analysis from the outputs of all antennas with an antenna gratings (AR) in the spatial channels of the detector-direction finder (OP), synchronous transfer to a lower frequency, synchronous transformation of signals in the time domain into digital form, calculation of fast Fourier transform samples of each digitized implementation in each spatial channel of the detector-direction finder, for each spectral report calculation of channel and mutual - interchannel energies of fast Fourier transform and accumulation of energies by summing their values calculated for each received signal, and forming a matrix

mutual energies equal to the product

accumulated matrix

mutual signal energies for a series of K> 1 measurements and a matrix

inverse to the correlation matrix

additive noise, formation of a unit vector

directions to the IRR in the terrestrial coordinate system (SC) according to the measured navigation parameters of the LPS, the formation of a one-dimensional vector complex radiation pattern of the AR with an arbitrary structure and directivity characteristics of antenna elements (

) for each detected signal at frequency

in the terrestrial SC, depending on the orientation of the LPS in space, the measurement of the values of the direction finding relief (PR) for each i-th detected signal at the frequency

from different azimuthal directions in the terrestrial SC, taking into account the interchannel correlation of spectral samples of the signal, calculating the maximum PR value

(φ - roll angle, θ - pitch angle, ψ - yaw angle); for each i-th detected signal at frequency

by possible azimuthal directions of radio wave arrival, estimation of the direction of radio wave arrival for each i-th detected signal at a frequency

, according to the invention , procedures for the detection of spectral components of signals adaptive to the unknown noise intensity and their identification by belonging to the same IRI are performed, the values of the PR adaptive to the unknown noise intensity are calculated for each i-th detected signal at the frequency

from different azimuthal directions in the terrestrial SC, taking into account the interchannel correlation of spectral samples of the signal according to the formula:

– матрица коэффициентов межканальной корреляции аддитивного шума;Where

- matrix of coefficients of interchannel correlation of additive noise;

с порогом h, выбираемым согласно критерию Неймана-Пирсона,

; в случае превышения значения решающей статистики порогового значения h, принимают решение о наличии ИРИ с направления

на частоте

.estimate the "reliability" of the direction finding of IRI based on the results of calculating and comparing the decisive statistics

with a threshold h selected according to the Neumann-Pearson criterion,

; in case the value of the decisive statistics exceeds the threshold value h, a decision is made on the presence of IRI from the direction

at frequency

...

More universal and consistent with the physical essence of the process of direction finding of a ground IRI from an LPS arbitrarily oriented in space seems to be the use of the following initial assumptions:

- the direction finding problem is formulated and solved in the same stationary earth CS, in which the concept of bearing to the IRI is defined and mathematically correct to use it to solve the problem of determining the coordinates of the IRI by a triangulation method;

- a change in the orientation of the LPS in space causes a corresponding change in the orientation of the AR in the earth's SC, and with it - a change in the “response” of the AR, characterized by the VKDN AR.

Indeed, the true values of the voltages at the outputs of the AA from the received radio wave of the IRI, which has a fixed azimuth, depend on the orientation angles of the AR, which must be taken into account by converting the VKDN ACR (and not the direction finding results) into a stationary CS.

The proposed method for detecting and azimuthal direction finding of ground-based radiation sources from a flight-lifting device includes the following procedures.

1. Multiple time-sequential synchronous reception of signals in the time domain (simultaneously falling into the current reception and analysis band) from the outputs of all antenna arrays in the spatial channels of the OP, synchronous transfer to a lower frequency, synchronous conversion of signals in the time domain into digital form, computation samples of fast Fourier transform of each digitized realization in each spatial channel of the detector-direction finder.

взаимных энергий, равной произведению

накопленной матрицы

взаимных энергий и матрицы

, обратной к матрице коэффициентов корреляции

аддитивного шума.2. For each spectral sample, the calculation of the channel and mutual (interchannel) energies of the fast Fourier transform and the accumulation of energies by summing their values calculated for each received signal, and the formation of a normalized matrix

mutual energies equal to the product

accumulated matrix

mutual energies and matrices

inverse to the matrix of correlation coefficients

additive noise.

– матрица взаимных энергий сигналов, «накопленная» по серии из K>1 измерений, с элементами

- a matrix of mutual signal energies "accumulated" over a series of K> 1 measurements, with elements

представляет собой сумму комплексных амплитуд радиосигнала ИРИ и шума:The value of the complex amplitude of the spectral component of the Fourier transform of the received radio signal at the output of the n-th antenna,

is the sum of the complex amplitudes of the SIR radio signal and noise:

– комплексная амплитуда радиосигнала;Where

- complex amplitude of the radio signal;

– соответственно азимут и угол места направления на источник излучения;

- respectively azimuth and elevation angle of direction to the radiation source;

– вектор аддитивного шума;

- vector of additive noise;

– комплексный отсчет (с порядковым номером nb =0…Nb-1) быстрого преобразования Фурье k-ого сигнала принятого в

-м пространственном канале обнаружителя-пеленгатора (совпадающий с номером антенны АР, подключенной ко входу канала);

- complex sample (with serial number nb = 0 ... Nb-1) fast Fourier transform of the kth signal received in

-th spatial channel of the direction finder detector (coinciding with the number of the AP antenna connected to the channel input);

1…N – порядковые номера пространственных каналов обнаружителя-пеленгатора;

1 ... N - serial numbers of the spatial channels of the detector-direction finder;

k = 1 ... K is the sequence number of the received signal in the time domain;

– матрица коэффициентов межканальной корреляции аддитивного шума (при отсутствии корреляции шума матрица является диагональной единичной);

- matrix of coefficients of interchannel correlation of additive noise (in the absence of correlation of noise, the matrix is a diagonal unit);

– оператор Эрмитова сопряжения,

- Hermitian conjugation operator,

– обратная матрица,

- inverse matrix,

– оператор следа матрицы.

- matrix trace operator.

3. Adaptive detection of spectral components of signals of IRI, which consists in the formation of a normalized matrix of mutual energies, according to the results of which the sums of the diagonal elements of the square of the normalized matrix and the square of the sum of the diagonal elements of the normalized matrix are simultaneously calculated, the results of which are substituted into the formula of the decision statistics and then compare the threshold selected by the Neumann-Pearson criterion. [Artemov M.L., Afanasiev O. V., Abramova E.L. Slichenko M.P. A method for adaptive spatial-multichannel detection of spectral components of signals from radio sources. RF patent No. 2696022 G01S 5/04 ].

4. Adaptive identification of spectral components by belonging to a signal of one IRI, which consists in the formation of a normalized matrix of mutual energies, according to the results of which the sums of diagonal elements and the products of sums of diagonal elements are simultaneously calculated, the calculation results of which are substituted into the decisive statistics, which is compared with the threshold selected by Neumann-Pearson criterion [Artemov ML, Afanasyev OV, Abramova EL .. Konenkov EA, Slichenko MP Method for adaptive identification of spectral components by belonging to the signal of one radio emission source. RF patent No. 2696093 G01S 5/04 ].

направления на ИРИ в земной СК по измеренным навигационным параметрам ЛПС:5. Formation of a unit vector

directions to the IRR in the terrestrial SC according to the measured LPS navigation parameters:

– матрица вращения ЛПС в трехмерном евклидовом пространстве [ГОСТ 20058-80. Динамика летательных аппаратов в атмосфере. Термины, определения и обозначения. М., 1981. № 3913, 52 с. (Издательство стандартов)], зависящая от углов пространственной ориентации: φ – угол крена, θ – угол тангажа, ψ – угол рысканья; Where

- LPS rotation matrix in three-dimensional Euclidean space [GOST 20058-80. Aircraft dynamics in the atmosphere. Terms, definitions and designations. M., 1981. No. 3913, 52 p. (Standards Publishing House)], depending on the angles of spatial orientation: φ - roll angle, θ - pitch angle, ψ - yaw angle;

имеет вид:Vector

looks like:

) для каждого обнаруженного сигнала на частоте

в земной СК, зависящей от ориентации ЛПС в пространстве.6. Formation of a one-dimensional VKDN AR with arbitrary structure and directivity characteristics of antenna elements
(

) for each detected signal at frequency

in the terrestrial SC, depending on the orientation of the LPS in space.

In the particular case of a flat annular equidistant antenna array

; n, N - serial number and number of AE,

;

f is the frequency of the EM wave, MHz;

– оператор Эрмитово сопряжения.

- operator of the Hermitian conjugation.

с различных азимутальных направлений в земной СК, с учетом межканальной корреляции спектральных отсчетов сигнала по формуле:7. Measurement of the values of the DF (DF) adaptive to the unknown noise intensity for each i-th detected signal at the frequency

from different azimuthal directions in the terrestrial SC, taking into account the interchannel correlation of spectral samples of the signal according to the formula:

– ВКДН АР ОП в земной СК, зависящая от истинного азимута на ИРИ и трех углов ориентации ЛПС.

- VKDN AR OP in the terrestrial SC, depending on the true azimuth to the IRI and three angles of orientation of the LPS.

для каждого i-го обнаруженного сигнала на частоте

по возможным азимутальным направлениям прихода радиоволны8. Calculation of the maximum value of the adaptive to the unknown noise intensity PR

for each i-th detected signal at frequency

along the possible azimuth directions of radio wave arrival

по формуле9. Evaluation of the direction of arrival of the radio wave for each i-th detected signal at the frequency

according to the formula

10. Evaluation of the reliability of direction finding results, including checking the fulfillment of the inequality

. В случае выполнения неравенства результат пеленгования считается достоверным, в противном случае – результат отбраковывается и не используется в последующей обработке наблюдаемых данных.where h is the threshold chosen according to the Neumann-Pearson criterion,

... If the inequality is satisfied, the direction finding result is considered reliable; otherwise, the result is discarded and not used in the subsequent processing of the observed data.

The proposed method for azimuthal detection and direction finding of ground-based IRI from an air-lifting device is devoid of the above-mentioned disadvantages of existing analogues, namely:

1. PR (4) takes into account the spatial orientation of the LPS: roll, pitch, yaw (course). A change in the orientation of the LPS in space causes a corresponding change in the orientation of the AR in the earth's SC, and with it, a change in the “response” of the AR, which is characterized by the VKDN AR.

2. The decisive rule of the proposed method is valid in the case of an antenna array with an arbitrary structure and directivity characteristics of the antenna elements. This allows the proposed method to be used in real operating conditions of detectors-direction finders, when there are mutual influences of antennas on each other.

3. Expression (4) for PR takes into account the presence of interchannel correlation due to the presence of external interference in real conditions, which allows, when developing detectors-direction finders, to analyze the achievable indicators of the effectiveness of direction finding of signals of radiation sources under conditions of a saturated electromagnetic environment,

4. The proposed method is devoid of direction finding errors associated with the low accuracy of determining the elevation angle to the ground-based SIR at ranges to LPS close to the radio horizon.

The proposed method of azimuthal detection and direction finding of ground-based IRI from a flight-lifting device is devoid of the above-mentioned disadvantages of the prototype, namely:

1. The proposed method involves the implementation of procedures for the detection of spectral components of signals, their identification by belonging to the same IRI, as well as the assessment of the "reliability" of the direction finding of the IRR in a saturated electromagnetic environment. The implementation of these procedures makes it possible to increase the performance indicators of the radio monitoring systems when determining the azimuth and elevation angle on the ERS with LPS in a real saturated electromagnetic environment, characterized by the saturation and congestion of the radio frequency spectrum.

2. The assessment of the "reliability" of the direction finding of the IRI carried out in the proposed method provides the necessary selection of the direction finding results (including, in the process of performing air maneuvers by the carrier, including a turn, with significant changes in the orientation angles of the aircraft, leading to the reception of radio signals outside the working sector of the angles) in terms of reliability with an increase in the accuracy and reliability of direction finding for IRI with LPS in real conditions.

3. The inventive method allows to take into account not only the presence of inter-channel correlation of the received spectral components of radio signals due to the presence of external interference in real conditions, but also, unlike the prototype, is efficient under conditions of a priori unknown interference intensity in various spatial reception channels. Efficiency indicators of the proposed method, including the characteristics of detection, identification of spectral components of signals by belonging to one IRI and estimation of the reliability of direction finding results are adaptive to the magnitude of the interference intensity.

The proposed method for detecting and azimuthal direction finding of ground-based radars from an airborne lifting device provides an increase in the efficiency of direction finding due to the fact that the method is based on the use of navigation information about the angles of the spatial orientation of the AR and converting not the results of direction finding, but the directivity characteristics of the AR (VKDN) from the associated mobile SC into a motionless SC connected to the Earth. This makes it possible to increase the accuracy and reliability of the azimuthal direction finding of the ground-based IRI, and the subsequent determination of the coordinates of the IRI by a triangulation method. Formula (4) PR takes into account the orientation of the LPS in space and the inter-channel correlation of radio signals due to the presence of external interference in real conditions, is valid in the case of an antenna array with an arbitrary structure and directivity characteristics of antenna elements.

(3) принимает вид:In the particular case, at zero angles of roll, pitch and yaw (φ is the roll angle, θ is the pitch angle, ψ is the yaw angle), the PR formula

(3) takes the form:

направления на ИРИ находится как аргумент глобального максимума ПР:Assessment

directions to the IRI is found as an argument for the global maximum PR:

.

...

Thus, the proposed method for detecting and azimuthal direction finding of ground-based radiation sources from a flight-lifting device is, in a particular case, applicable when placing the OP on the Earth's surface, which expands the field of applicability of the proposed method.

A diagram of a device for implementing the proposed method is shown in Fig. 1, where it is indicated:

1 - block of multiple multichannel reception of temporary realizations and transfer to a lower frequency;

2 - block for digitizing temporary realizations;

3 - block for calculating the Fourier transform of time realizations;

4 - block for calculating channel spectra;

5 - block for calculating mutual spectra;

6 - block of accumulation of matrices of mutual energies;

7 - block for detecting spectral components of signals of radiation sources;

8 - block for identification of spectral components by belonging to a signal of one radio source;

9 - block for storing the current navigation parameters of the LPS (roll, pitch, yaw);

направленности элементов АС в земной системе;10 - unit for generating unit vector values

directivity of the AU elements in the terrestrial system;

11 - block of formation of VKDN AR in the terrestrial SC;

12 - block of formation of PR values;

13 - block for determining the maximum PR;

14 - block for assessing the reliability of the direction to the IRI.

направленности элементов АС в земной системе 10, блок формирования ВКДН АС в земной СК 11, блок формирования значений ПР 12 и блок определения максимума ПР 13 соединен с входом блока оценки достоверности направления на ИРИ 14, выход которого является выходом устройства . The device (detector-direction finder) contains a serially connected unit for multiple multichannel reception of temporal realizations and transfer to a lower frequency 1, a unit for digitizing temporal realizations 2 and a unit for calculating the Fourier transform of temporal realizations 3, the outputs of which are connected respectively to the inputs of the channel spectra computation unit 4 and the unit calculating mutual spectra 5. In this case, the outputs of the blocks for calculating the channel spectra 4 and calculating the mutual spectra 5 are connected to the corresponding inputs of the block for accumulating the matrices of mutual energies 6, the output of which is through the serially connected block 7 for detecting spectral components of the signals of the IRI signal of one source of radio emission, block for storing the current navigation parameters of LPS in space 9, block for generating unit vector values

directivity of the elements of the speaker in the terrestrial system 10, the unit for forming the VKDN AS in the terrestrial SC 11, the unit for forming the values of PR 12 and the unit for determining the maximum PR 13 is connected to the input of the unit for assessing the reliability of the direction to the IRI 14, the output of which is the output of the device .

The device for implementing the proposed method operates as follows.

. По каждому из анализируемой пары спектральных отчетов преобразования Фурье с помощью блока 4 выполняется вычисление действительных канальных

и параллельно с этим в блоке 5 вычисление комплексных взаимных энергий

. Unit 1 carries out multiple, time-sequential synchronous (coherent) reception of time realizations from the outputs of all AC antennas in the spatial channels of the direction finder detector and coherent transfer to a lower frequency. Then block 2 synchronously converts the received temporary realizations into digital form. In block 3 for each digitized implementation in each spatial channel of the detector-direction finder, the Fourier transform counts are calculated

... For each of the analyzed pair of spectral reports of the Fourier transform using block 4, the calculation of the actual channel

and in parallel with this, in block 5, the calculation of complex mutual energies

...

According to the results of calculating blocks 4 and 5 in block 6, for each pair of spectral reports, for each of the received time realizations of the channel and mutual energies of the spectral components is accumulated by summing their values calculated for each of the received time realizations

направления на ИРИ в земной СК с учетом сформированных в блоке 9 навигационных параметров ЛПС (формула 2). Затем в блоке 11 формируется ВКДН АР (

) для каждого обнаруженного сигнала на частоте

в земной СК, зависящей от ориентации ЛПС в пространстве по формуле (3). По результатам вычислений в блоке 12 формируются значения пеленгационного рельефа (ПР) для каждого обнаруженного сигнала на частоте

с различных направления в земной СК, с учетом межканальной корреляции спектральных отсчетов временных реализаций по формуле (4). В блоке 13 вычисляют максимальное значения ПР

для каждого обнаруженного сигнала на частоте

по возможным направлениям прихода радиоволны по формуле (5). В блоке 14 оценивают на достоверность возможное направление ИРИ по формуле (6). В случае превышения порога, выбираемого по критерию Неймана-Пирсона, направление

принимается за истинное направление ИРИ.In the block of adaptive spatial-multichannel detection of spectral components of signals 7, a normalized matrix of mutual energies is formed, according to the results of which the sums of the diagonal elements of the square of the normalized matrix and the square of the sum of the diagonal elements of the normalized matrix are simultaneously calculated, the results of the calculations are substituted into the formula of the decisive statistics [Artemov ML, Afanasiev O. V., Abramova E. L. Slichenko M. P. A method for adaptive spatial-multichannel detection of spectral components of signals from radio sources. RF patent No. 2696022 G01S 5/04 ] and then compare the decisive statistics with a threshold selected by the Neumann-Pearson criterion. If the threshold in block 8 is exceeded, the spectral components are identified by belonging to the signal of one radio emission source by forming a normalized matrix of mutual energies, based on the results of which the sums of the diagonal elements and the products of the sums of the diagonal elements are simultaneously calculated, the results of which are substituted into the decisive statistics, which is compared with the threshold, selected by the criterion of Neumann-Pearson [Artemov ML, Afanasiev OV, Abramova EL .. Konenkov EA, Slichenko MP Method for adaptive identification of spectral components by belonging to the signal of one radio emission source. RF patent No. 2696093 G01S 5/04 ]. In block 9, the current navigation parameters of the LPS (roll, pitch, yaw) are stored. Further, in block 10, the values of the unit vector

directions to the IRI in the earth's spacecraft taking into account the LPS navigation parameters formed in block 9 (formula 2). Then, in block 11, VKDN AR (

) for each detected signal at frequency

in the terrestrial SC, depending on the orientation of the LPS in space according to the formula (3). Based on the results of calculations in block 12, the values of the direction finding relief (DF) are formed for each detected signal at the frequency

from different directions in the terrestrial SC, taking into account the interchannel correlation of spectral readings of time realizations according to formula (4). In block 13, the maximum values of the PR

for each detected signal at frequency

along the possible directions of radio wave arrival according to the formula (5). In block 14, the possible direction of the IRI is evaluated for reliability according to the formula (6). In case of exceeding the threshold selected by the Neumann-Pearson criterion, the direction

taken as the true direction of the IRI.

и

, при бесконечно большом отношении сигнал/шум. Анализ статистических характеристик распределения решающей статистики, вычисленной по формуле (4), был проведен в пакете моделирования Matlab. Количество накоплений взаимных спектров сигналов полагалось равным 3.The results of statistical modeling of the method of detection and azimuth direction finding of ground-based radiation sources from the flight-lifting device are obtained. FIG. Figures 2 - 4 show the results of statistical modeling for a seven-element (N = 7) equidistant ring antenna array with the ratio of the ECAR radius to the wavelength

and

, at an infinitely large signal-to-noise ratio. The analysis of the statistical characteristics of the distribution of the decisive statistics calculated by the formula (4) was carried out in the Matlab simulation package. The number of accumulations of mutual signal spectra was set equal to 3.

(фиг. 1а-4а) и при

(фиг. 1б - 4б). В связанной СК с АР азимут полагался равным 180 град., угол места – 0 град. Сплошная кривая – ФН, построенная с учетом навигационных параметров ЛПС, пунктирная кривая – ФН, построенная без учета ориентации ЛПС в пространстве. Расчеты проведены при следующих значениях углов ориентации ЛПС:

 – для рис.1 а,б;

 – для рис.2 а,б;

 – для рис.3 а,б;

 – для рис.4 а,б. FIG. 2 shows the azimuthal dependence of the uncertainty function (FN) - the direction finding relief with an infinitely large signal-to-noise ratio - in the case of an OP with a seven-element ECAR with a ratio of the grating radius to the wavelength

(Fig. 1a-4a) and at

(Figs.1b - 4b). In the connected SC with the AR, the azimuth was assumed equal to 180 degrees, the elevation angle was 0 degrees. The solid curve is the FN, built taking into account the navigation parameters of the LRS, the dashed curve is the FN, built without taking into account the orientation of the LRS in space. The calculations were performed for the following values of the LPS orientation angles:

- for Fig. 1 a, b;

- for Fig. 2 a, b;

- for Fig. 3 a, b;

- for Fig. 4 a, b.

(фиг. 3а) и

(фиг. 4а), на фиг. 3б – 4б приведены азимутальные срезы данных ФН при значениях угла места

(сплошная кривая) и

(пунктирная кривая). FIG. Figures 3a - 4a show the dependences of the FN on the azimuth and elevation angle at zero angles of LPS orientation, the ratio of the grating radius to the wavelength

(Fig.3a) and

(Fig. 4a), Fig. 3b - 4b shows the azimuthal slices of the FN data at the values of the elevation angle

(solid curve) and

(dashed curve).

и угла прихода радиоволны в плоскости, перпендикулярной плоскости АР, возрастает уровень боковых лепестков ФН, что приводит к повышению вероятности аномальной ошибки пеленгования.The figures show that with an increase in the ratio of the grating radius to the wavelength

and the angle of arrival of the radio wave in the plane perpendicular to the plane of the AA, the level of the side lobes of the FN increases, which leads to an increase in the probability of anomalous direction finding error.

при углах места прихода радиоволны 15 и 20 градусов. Выполнялся поиск МУБЛ в круговом азимутальном секторе от 0 до 360 градусов. Сплошная кривая соответствует способам азимутального пеленгования в СК, связанной с АР, и получена в результате нахождения МУБЛ азимутального срезу двумерной ФН (т.е. при угле места, равном нулю). Пунктирная кривая соответствует предлагаемому способу пеленгования, основанному на преобразовании ВКДН АР в неподвижную СК, связанную с Землей, и получена в результате нахождения максимального уровня бокового лепестка азимутального среза двумерной ФН при истинном угле места.Figures 5 and 6 show the dependence of the maximum side lobe level (MUBL) FN on the ratio of the radius of the seven-element grating to the wavelength

at angles of arrival of radio waves 15 and 20 degrees. The search for MUBL was carried out in a circular azimuth sector from 0 to 360 degrees. The solid curve corresponds to the methods of azimuthal direction finding in the SC associated with the AA, and is obtained as a result of finding the MUBL azimuthal cut of the two-dimensional FN (i.e., at an elevation angle equal to zero). The dashed curve corresponds to the proposed direction finding method based on the transformation of the VKDN AR into a stationary SC connected to the Earth, and is obtained as a result of finding the maximum level of the side lobe of the azimuthal cut of the two-dimensional FN at the true elevation angle.

= 1,3 увеличивается с 0,68 до 0,82, при

= 1,9 увеличивается с 0,82 до 0,94, при

= 2,3 увеличивается с 0,82 до 1,0. Таким образом, в указанном случае при значении

= 2,3 азимутальное пеленгование становится недостоверным. По критерию: МУБЛ не более 0,82, верхняя частота рабочего диапазона ОП с семиэлементной решеткой уменьшается с 2,86 до 1,3 при ориентации АР в пространстве, обеспечивающих угол прихода радиоволны более 20 градусов в вертикальной плоскости относительно плоскости АР. Применение предлагаемого способа обнаружения и пеленгования позволяет в указанных условиях по этому же критерию обеспечить практически неизменной верхнюю частоту рабочего диапазона. It can be seen that the lack of conversion of the VKDN AR from a coupled SC to a stationary SC linked to the Earth in the methods of azimuth direction finding leads to a decrease in the upper frequency of the operating frequency range. So, with the orientation of the AA in space, providing an angle of arrival of the radio wave of 20 degrees in the vertical plane relative to the plane of the AR, the MUBL at

= 1.3 increases from 0.68 to 0.82, with

= 1.9 increases from 0.82 to 0.94, with

= 2.3 increases from 0.82 to 1.0. Thus, in this case, with the value

= 2.3 azimuth bearing becomes unreliable. According to the criterion: MUBL no more than 0.82, the upper frequency of the operating range of the OP with a seven-element lattice decreases from 2.86 to 1.3 when the AA is oriented in space, providing an angle of arrival of the radio wave of more than 20 degrees in the vertical plane relative to the plane of the AR. The use of the proposed method of detection and direction finding allows, under the indicated conditions, according to the same criterion, to provide practically unchanged upper frequency of the operating range.

Thus, the use of navigation information about the angles of the spatial orientation of the AR allows the search for the azimuth on the SAR in the curvilinear cut of the two-dimensional azimuthal-elevation direction-finding relief corresponding to the evolution of the orientation of the direction of arrival of the radio wave in the azimuth circle with an arbitrary orientation of the LPS. The proposed method of direction finding, based on the conversion of the VKDN AR from a coupled SC to a terrestrial one, taking into account the LPS orientation angles, makes it possible to increase the accuracy and reliability of the azimuthal direction finding of the ground AIR, and the subsequent determination of the coordinates of the AIR by a triangulation method.

The achieved technical result is an increase in the efficiency of azimuth direction finding of ground-based IRI by a multi-channel direction finder.

The technical result is achieved through the use of navigation information about the angles of the spatial orientation of the AR and the conversion not of the results of direction finding, but of the directivity characteristics of the AR from a connected mobile SC into a stationary SC connected to the Earth. This makes it possible to carry out direction finding and search for the azimuth on the SAR in a curvilinear cut of the two-dimensional azimuthal-elevation direction finding relief corresponding to the evolution of the orientation of the vector of the direction of arrival of the radio wave in the azimuth circle with an arbitrary orientation of the AR located on the LPS. Due to this accounting of information about the orientation of the LPS, an increase in the accuracy and reliability of the direction finding of ground-based RES, and the subsequent determination of the coordinates of ground-based RES by a triangulation method, is provided.

Based on the results of the spatial-multichannel detection of spectral components of the radio signals of SIR, the identification of the components by belonging to the signals of the same SIR, the direction to the SIR is estimated by global maximization of the decisive function - the direction finding relief, which depends on the VKDN AR OP accumulated in a series of measurements of the matrix of mutual spectral energies. the signal component of the IRI and the covariance matrix of the additive noise.

VKDN AR characterizes the structure and directivity characteristics of the antenna elements of the AR in the azimuthal-elevation plane and is determined in the SC associated with the AR . In view of this, the position of the global maximum of the direction finding relief corresponds to the estimates of the orientation angles of the unit vector of the direction of arrival of the radio wave in the SC associated with the AR, and in the case of a flat AR, the angles of orientation relative to the plane of the antenna elements.

We will formulate the problem of azimuthal direction finding of ground-based IRI with LPS as follows: based on the set of observed data - complex amplitudes of voltages at the outputs of the AR of the OP, as well as measurements of the orientation angles of the LPS in space, it is necessary to develop a rule for making a decision on a fair statistical hypothesis: about the presence or absence of a radio wave of IRI, emitting from a certain azimuth in a stationary earth SC (topographic projection of Gauss-Kruger).

Claims (4)

A method for detecting and azimuthal direction finding of ground-based sources of radio emission (IRS) from a flight-lifting facility (LPS), including multiple time-sequential synchronous reception of signals in the time domain, simultaneously falling into the current reception band and analysis from the outputs of all antennas of the antenna array (AR) in spatial channels of the detector-direction finder (OP), synchronous transfer to a lower frequency, synchronous transformation of signals in the time domain into digital form, calculation of fast Fourier transform samples of each digitized realization in each spatial channel of the detector-direction finder, for each spectral report, the calculation of channel and mutual - interchannel energies of fast Fourier transform and accumulation of energies by summing their values, calculated for each received signal, and forming a matrix

mutual energies equal to the product

accumulated matrix

mutual signal energies for a series of K > 1 measurements and a matrix

inverse to the correlation matrix

additive noise, the formation of a unit vector k _{0 of the} direction to the IRR in the terrestrial coordinate system (SC) according to the measured navigation parameters of the LPS, the formation of a one-dimensional vector complex radiation pattern of the antenna array with arbitrary structure and directivity characteristics of antenna elements

for each detected signal at frequency

in the terrestrial SC, depending on the orientation of the LPS in space, the measurement of the values of the direction finding relief (PR) for each i-th detected signal at the frequency

from different azimuthal directions in the terrestrial SC, taking into account the interchannel correlation of spectral samples of the signal, calculating the maximum PR value

(ϕ is the roll angle, θ is the pitch angle, ψ is the yaw angle); for each i-th detected signal at frequency

by possible azimuthal directions of radio wave arrival, estimation of the direction of radio wave arrival for each i-th detected signal at a frequency

, characterized in that the procedures for the detection of spectral components of signals adaptive to the unknown noise intensity and their identification by belonging to the same IRI are performed, the values of the PR adaptive to the unknown noise intensity are calculated for each i- th detected signal at the frequency

from different azimuthal directions in the terrestrial SC, taking into account the interchannel correlation of spectral samples of the signal according to the formula:

Where

- matrix of coefficients of interchannel correlation of additive noise; estimate the "reliability" of the direction finding of IRI based on the results of calculating and comparing the decisive statistics

with a threshold h selected according to the Neumann-Pearson criterion,

, if the value of the decision statistics exceeds the threshold value h , a decision is made on the presence of IRI from the direction

at frequency

...

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