RU2557784C1 - Method for gate identification of signals with radio-frequency sources in multi-target environment - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: electronic surveillance system calculates estimates $${\widehat{X}}_{j,i}\left(k\right)$$

of status coordinates of detected and tracked radio-frequency sources, based on which results of measuring coordinates X_in,i(k), obtained at the k-th moment in time, are identified with the corresponding radio-frequency sources, wherein for each status coordinate of each detected and tracked radio-frequency source, the method includes determining an interval of values which depends on variance of measurement of X_in,i(k), the variance of the rate of measuring status coordinates $${\dot{X}}_{j,i}\left(k\right),$$

as well as the coefficient of proportionality K, the value of which is selected in the range of 1 to 2. The set of intervals on all status coordinates of each radio-frequency source forms a multidimensional gate, where if the measurement result of the status vector X_in(k) at the k-th moment in time falls in said gate, the result is identified with, for example, a specific radio-frequency source. If the measured vector X_in(k) does not fall within any of the gates of the j-th radio-frequency source, where $$j=\overline{\mathrm{1,}N},$$

a new radio-frequency source with an index N+1 is detected.

EFFECT: high reliability of identifying signals in a multi-target environment.

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Description

The invention relates to radar and can be used to improve the accuracy of determining the location (MP) and other parameters of ground-based sources of radio emissions (IRI) using radio intelligence systems (SRTR).

The expected high saturation of the military areas of Iran for various purposes creates a complex (multipurpose) electronic environment and predetermines the fundamental need for the SRTR to solve the following problems:

- identification of Iran by type, instance and tactical purpose;

- tracking of detected IRI for all significant information parameters: carrier frequency, repetition period (repetition interval) and pulse duration, signal spectrum width, location, etc.

The relevance of solving these problems is due, in particular, to the need to assess threats with the ranking of Iran according to the degree of importance and issue targeting commands, for example, anti-radar missiles to destroy the most dangerous targets. It should be emphasized that the success of solving these problems in a multi-purpose environment largely depends on the ability of the SRTR to identify the received signals with specific copies of the IRI, which determines the potential for their reliable support.

Here, the identification of signals is understood as the process of one-to-one establishment of the belonging of the received signals to specific copies of the IRI in a multi-purpose environment. The process of correct identification of signals does not cause significant difficulties if the signals received from various IRI have stable differences in the numerical values of the radio technical parameters. Otherwise, when several identical IRIs are in the observation zone, the probability of mistaken identification of their signals increases sharply.

In [1, 2] identification methods used in airborne direction-finding systems for processing the measured azimuths of IRI are presented. Among them, the so-called “areal” method, which is considered as a prototype, is most often used in practice.

The “areal” method for identifying azimuth bearings is illustrated in FIG. 1. It is assumed that at points x ₁ , x ₂ , x ₃ , ... bearings are measured, for example, α ₁ , β ₁ , α ₂ , β ₂ , α ₃ , β ₃ ... on IRI “A” and IRI “B "Respectively. In this intersection point bearings, measured at different points on the same IRI grouped within small regions, called confidence region (TO) and a predetermined confidence level of P _rows includes true point MP IRI. The intersection points of bearings measured on different IRIs are distributed over a relatively large area and are not densely grouped. Bearings intersecting within the BS are identified with the IRI to which this area belongs. Bearing intersection points located outside the BS determine the location of false (non-existent) IRI.

The disadvantage of the "areal" method is the impossibility of processing other parameters of the received signals (except bearings), as well as the joint processing of several different types of parameters.

Below, we will propose a more rational method for identifying received signals with specific instances of detected (accompanied) IRI in a multipurpose environment, based on the use of multidimensional gates (confidence areas) according to measured phase coordinates (parameters), using the “reliability - computational cost” criterion. In this case, it will be assumed that the following conditions are met:

1) CPTR is designed to estimate the n coordinates of the state of the IRI, combined into a vector

each of N radio emission sources in the presence of appropriate measurements

2) IRI signals do not arrive at the SRTR in the general case at the same time, and the measurement results are determined by the model

where k is the number of the time discrete, ξ _{j, i} (k) are the centered uncorrelated Gaussian noises with the known dispersion D and _{j, i} (k) at the kth moment in time;

координат состояния всех обнаруженных ИРИ являются известными и получены на k-й момент времени по результатам предыдущих измерений.3) estimates $${\widehat{X}}_{j,i}\left(k\right)$$

the coordinates of the state of all detected IRIs are known and obtained at the k-th point in time according to the results of previous measurements.

In the process of developing the proposed identification method, it is necessary to solve two problems:

1) determine the size of the gates, guaranteeing the required reliability of identification;

2) to formulate a decision-making rule on whether the obtained measurements belong to a specific IRI.

In solving these problems, it will be assumed that for a time equal to Δt (k) = t _k -t _k-1 , the coordinates (1) of the IRI state change according to the law

- скорость изменения оцениваемого параметра.Where $${\dot{X}}_{j,i}\left(k-\mathrm{one}\right)$$

- rate of change of the estimated parameter.

Then, taking into account (3) and (4), the increment of measurements and its dispersion over the interval Δt (k) will be determined by the expressions, respectively [3]

- дисперсия скорости изменения параметров [3].Where

- variance of the rate of change of parameters [3].

могут определяться по правилу

вытекающему из соотношения

Для большинства параметров наземных (морских) неподвижных (малоподвижных) ИРИ, не зависящих от перемещений самолета-носителя СРТР, можно полагать

It should be noted here that the numerical values

can be determined by the rule

arising from the relation

For most parameters of land (sea) fixed (inactive) IRI, independent of the movements of the carrier aircraft SRTR, we can assume

Since process (3) is Gaussian, then all increments (5) must fall within the range of 0.997 with probability

In this case, the gate size ΔX and _{j, i} (k) _max for the j-th IRI in the i-th measured phase coordinate must satisfy the condition

where K = 1 ... 2 ensures the fulfillment of condition (8) with a predetermined probability P = 0.68 ... 0.95, and D and _{j, i} (k) is the dispersion of measurement noise ΔX and _{j, i} (k) _max .

Expression (8) determines the strobe size for each j-th IRI for each i-th phase coordinate, and also determines the use of the following identification decision rule. If all measurements _{Xin, i} (k) belonging at the k-th instant of time to an unknown instance of IRI satisfy the condition

то принимается решение об их отождествлении с фазовыми координатами j-го ИРИ. При этом результат отождествления представляется в виде вектора X_иj*(k)=X_ин. Здесь X_иj*(k)=[X_иj*,1(k), X_иj*,2(k), …, X_иj*i(k), …, X_иj*,i(k)], а X_ин(k)=[X_ин,1(k), X_ин,2(k), …, X_ин,i(k), …, X_ин,i(k)], где j* - индекс ИРИ, с которым отождествлен измеренный вектор параметров X_ин(k). Если условие (9) не выполняется хотя бы по одной из n координат, то проверяется выполнение этого условия для следующего экземпляра сопровождаемого ИРИ в соответствии с выражением

then a decision is made on their identification with the phase coordinates of the j-th IRI. Moreover, the identification result is represented in the form of a vector X and _{j *} (k) = X _in . Here X and _{j *} (k) = [X and _{j *, 1} (k), X and _{j *, 2} (k), ..., X and _{j * i} (k), ..., X and _{j *, i} (k)], and X _in (k) = [X _{in, 1} (k), X _{in, 2} (k), ..., X _{in, i} (k), ..., X _{in, i} (k)], where j * is the IRI index with which the measured parameter vector X _in (k) is identified. If condition (9) is not satisfied in at least one of the n coordinates, then this condition is checked for the next instance of the followed IRI in accordance with the expression

and so on for all detected (accompanied) IRI. If conditions (9), (10) are not satisfied for any of the detected (accompanied) copies of IRI, then a decision is made to detect a new IRI, i.e. j * = N + 1.

- от системы формирования оценок координат состояния ИРИ. Координаты МП и оценки координат состояния также подаются на УС, которая реализует алгоритм, определяемый выражениями (9), (10). По результатам сравнения принимается решение о принадлежности принятых сигналов соответствующим j*-м ИРИ либо об обнаружении новых ИРИ cj*=N+1.In FIG. Figure 2 shows a simplified block diagram of one of the possible variants of a system that implements the proposed method for gate identification of IRI bearings in a multi-purpose environment. The system includes an n-channel meter of parameters of received signals (I) 3, a comparison device (CSS) 4, as well as an on-board computer system (BVS) 5. The received signals are sent to a meter And, which generates results X _{in, i} (k), which are supplied to the DC, as well as to the BVS, which calculates, in accordance with (8), the sizes of the gates ΔX and _{j, i} (k) _max . In this case, information about the location of the CPTR and its speed comes from the navigation system, and the values $${\widehat{X}}_{j,i}\left(k\right)$$

- from the system of forming estimates of the coordinates of the state of Iran. MP coordinates and state coordinate estimates are also submitted to the CSS, which implements the algorithm defined by expressions (9), (10). Based on the results of the comparison, a decision is made whether the received signals belong to the corresponding j * th IRI or to detect new IRI cj * = N + 1.

The implementation of the above method will improve the reliability of the identification of signals in a multi-purpose environment and thereby provide a high-quality location of detected IRIs and their reliable tracking.

LITERATURE

1. Melnikov Yu.P. Aerial radio intelligence (methods for evaluating effectiveness). M .: Radio engineering, 2005.

2. Melnikov Yu.P., Popov S.V. Radio intelligence. Methods for assessing the effectiveness of the determination of radiation sources. M .: Radio engineering, 2008.

3. Tikhonov V.I. Statistical radio engineering. 2nd ed., Revised. and add. M .: Radio and communication, 1982.

Claims (1)

The method of strobed identification of signals with sources of radio emission (IRI) in a multi-purpose environment, which consists in the fact that the radio intelligence system calculates the estimates

ix coordinates of the state of j-detected and accompanied by IRI, on the basis of which the results of measuring the coordinates of the state X _{in, i} (k) obtained at the k-th moment of time are identified with the corresponding IRI, characterized in that for each i-th coordinate the state of each j-th detected and accompanied by IRI is determined by the interval of values

where ΔX and _{j, i} (k) _max is the strobe size for the j-th IRI by the i-th measured state coordinate;
K is the proportionality coefficient, the value of which is selected in the range from 1 to 2, ensuring the fulfillment of (1) with a predetermined probability;

- variance of the rate of change of state coordinates

Δt (k) = t _k -t _k-1 is the time discrete;
D and _{j, i} (k) is the variance of the measurement of the quantity X and _{j, i} (k);
and also the set of intervals along all the coordinates of the state of each IRI forms a multidimensional strobe, when it falls into which the result of measuring the state vector X _in (k) at the k-th moment of time is identified with a specific IRI, if the measured vector X _in (k) is not hit the limits of none of the gates of the j-th Iran, where

then a decision is made to detect a new IRI with index N + 1.

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