RU2567243C1 - Method of identifying aerial targets - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to radio engineering and can be used in designing means of identifying aerial targets. The method includes using, in an active response radar system, additional selection of an interrogation signal based on spatial coordinates of a detected aerial target, which includes selecting, at the side of each i-th aerial vehicle from a plurality interrogation signals, an interrogation signal addressed to said aerial vehicle, where

I is the number of aerial vehicles in the coverage area of airborne interrogation radar, having an airborne radar transponder on-board. Said procedure is carried out by comparing eigen spatial coordinates of the i-th aerial vehicle and spatial coordinates of the aerial target detected by the on-board radar of the interrogating aerial vehicle, the information on which is transmitted in the interrogation signal, which enables to reduce the spatial volume of uncertainty of the active response radar system to sizes defined by measurement errors of the spatial coordinates of the detected aerial target, as well as measurement errors of the spatial coordinates of the location of the interrogating and i-th aerial vehicles.

EFFECT: high probability of correct identification of aerial targets detected by on-board radar in a multi-target environment owing to reduced uncertainty of the active response radar system.

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Description

The invention relates to the field of radio engineering and can be used to create means of identifying air targets detected by an airborne radar station.

Closest to the technical nature of the claimed method (prototype) is a method for identifying air targets, implemented in a radar system with an active response (RSAO) (see, for example, Radar systems of multi-functional aircraft. T. 1. Radar - information basis of military operations of multi-functional aircraft Systems and algorithms for primary processing of radar signals. / Edited by A.I. Kanaschenkov and V.I. Merkulov. - M.: “Radio Engineering”, 2006. - 656 p. S. 623).

The disadvantages of this method include the low probability of correct identification of air targets in a multi-purpose environment. The main reasons for this are errors resulting from the superposition of the response signals of several aircraft within the RSAO uncertainty, and errors resulting from the linking to the detected air target of the response signal of another aircraft that is within the RSAO uncertainty.

The technical result of the invention is to increase the likelihood of correct identification of air targets detected by an airborne radar in a multipurpose environment, by reducing the volume of uncertainty of RSAO by applying a query signal selection by the spatial coordinates of airborne targets detected by an airborne radar.

, I - число воздушных судов, находящихся в зоне действия самолетного радиолокационного запросчика, имеющих на борту самолетный радиолокационный ответчик, формировании и передаче кодированного ответного сигнала самолетным радиолокационным ответчиком со стороны каждого i-го воздушного судна, приеме и обработке данных ответных сигналов, а также формировании решения об идентификационном признаке воздушной цели самолетным радиолокационным запросчиком, формируют на стороне запрашивающего воздушного судна оценки декартовых координат обнаруженной воздушной цели и соответствующие дисперсии в относительной системе координат, кодируют запросный сигнал информацией, содержащей оценки декартовых координат обнаруженной воздушной цели в относительной системе координат и соответствующие дисперсии, на стороне каждого i-го воздушного судна выделяют из принятого запросного сигнала оценки декартовых координат обнаруженной воздушной цели в относительной системе координат и соответствующие дисперсии, из навигационной системы каждого i-го воздушного судна вводят оценки его декартовых координат и соответствующие дисперсии, оценивают расстояние R_i между обнаруженной воздушной целью и i-м воздушным судном, определяют пороговое значение h_i по расстоянию между обнаруженной воздушной целью и i-м воздушным судном, если R_i<h_i, то формируют решение о совпадении пространственных координат обнаруженной воздушной цели и i-го воздушного судна и передают ответный сигнал, в противном случае ответный сигнал не передают.This result is achieved by the fact that in the known method of identifying air targets implemented in the RSAO, based on the detection of an air target using an airborne radar on the side of the requesting aircraft, generating and transmitting the encoded request signal by an aircraft radar interrogator, receiving and processing this request signal by an aircraft radar defendant on the side of each i-th aircraft, where

, I - the number of aircraft in the coverage area of the aircraft radar interrogator, having on board the aircraft radar transponder, the formation and transmission of the encoded response signal by the aircraft radar transponder from the side of each i-th aircraft, the reception and processing of data response signals, as well as the formation of decisions on the identification mark of an air target by an aircraft radar interrogator form on the side of the requesting aircraft an estimate of the Cartesian coordinates airborne targets and the corresponding variances in the relative coordinate system, encode the request signal with information containing estimates of the Cartesian coordinates of the detected air target in the relative coordinate system and the corresponding variances on the side of each i-th aircraft, from the received request signal estimates the Cartesian coordinates of the detected air target in the relative coordinate system and the corresponding variances, estimates of its decars are introduced from the navigation system of each i-th aircraft coordinates and the corresponding variances, estimate the distance R _i between the detected air target and the i-th aircraft, determine the threshold value h _i from the distance between the detected air target and the i-th aircraft, if R _i <h _i , then form a decision on coincidence of the spatial coordinates of the detected air target and the i-th aircraft and transmit a response signal, otherwise the response signal is not transmitted.

The essence of the invention lies in the application in the RSAO, along with existing types of selection of the interrogation signal, additional selection of the interrogation signal according to the spatial coordinates of the detected air target. By additional selection of the interrogation signal according to the spatial coordinates of the detected air target, it is understood that on the side of each i-aircraft there is a selection of the interrogation signals of the interrogation signal addressed to the aircraft from the set of interrogation signals. This procedure is carried out by comparing the spatial coordinates of the i-th aircraft and the spatial coordinates of the air target detected by the airborne radar of the requesting aircraft, information about which is transmitted in the request signal. This allows us to reduce the spatial volume of RSAO uncertainty to sizes determined by errors in measuring the spatial coordinates of the detected air target, as well as errors in measuring the spatial coordinates of the location of the requesting and i-th aircraft.

This method includes the following steps:

1. On the side of the requesting aircraft:

- detection of an air target and the formation of estimates of its polar coordinates J ₁ = [D ₁ , α ₁ , β ₁ ] ^T in the associated coordinate system with the corresponding dispersions D [J ₁ ] using the airborne radar, where D ₁ is the distance to the detected air target , α ₁ - bearing of the detected air target in the horizontal plane, β ₁ - bearing of the detected air target in the vertical plane;

- input from the airborne radar estimates of the polar coordinates of the detected air target J ₁ = [D ₁ , α ₁ , β ₁ ] ^T in the associated coordinate system with the corresponding variances D [J ₁ ];

- the formation of estimates of the Cartesian coordinates of the location of the requesting aircraft X ₀ = [x ₀ , y ₀ , z ₀ ] ^T and the angular coordinates W ₀ = [ψ ₀ , ϑ ₀ , γ ₀ ] ^T , characterizing its spatial orientation in the relative coordinate system with the corresponding variances D [X ₀ ] and D [W ₀ ] using the navigation system, where ψ ₀ is the yaw angle, ϑ ₀ is the pitch, γ ₀ is the roll.

- input from the navigation system estimates the Cartesian coordinates of the location of the requesting aircraft X ₀ = [x ₀ , y ₀ , z ₀ ] ^T and the angular coordinates W ₀ = [ψ ₀ , ϑ ₀ , γ ₀ ] ^T , characterizing its spatial orientation in relative coordinate system with the corresponding variances D [X ₀ ] and D [W ₀ ];

- recalculation of the estimates of the polar coordinates of the air target J ₁ in the Cartesian coordinates X _{1 of the} associated coordinate system in accordance with the expression

- recalculation of the estimates of the Cartesian coordinates of the detected air target from the associated coordinate system in the normal coordinate system in accordance with the expression

where A ^{c → g} is the transition matrix from the connected coordinate system to the normal coordinate system,

- recalculation of the estimates of the Cartesian coordinates of the detected air target X _1g from the normal coordinate system to the relative coordinate system in accordance with the expression

- the formation of a matrix of variances of estimates of the Cartesian coordinates of the location of the detected air targets in a normal coordinate system in accordance with the expression

Where

,

,

,

,

,

,

,

,

.

.

- determination of variances of the estimates of the Cartesian coordinates of the detected air target in the relative coordinate system in accordance with the expression

- generation and transmission of an encoded request signal with information about the Cartesian coordinates of the location of the detected air target X ₁ in the relative coordinate system and the corresponding dispersions D [X ₁ ] using an aircraft radar interrogator;

2. On the i-th aircraft side:

- receiving and processing the encoded request signal using an aircraft radar transponder with the release of information about the estimates of the Cartesian coordinates of the location of the detected air target X ₁ in the relative coordinate system and the corresponding variances D [X ₁ ];

- the formation of estimates of the Cartesian coordinates of the i-th aircraft X _i = [x _i , y _i , z _i ] ^T in the relative coordinate system and the corresponding variances D [X _i ] using the navigation system;

;- input from the navigation system estimates the Cartesian coordinates of the i-th aircraft X _i = [x _i , y _i , z _i ] ^T in the relative coordinate system and the corresponding variances

;

- an estimate of the distance R _i between the detected target and the i-th aircraft in accordance with the expression

- calculation of the threshold value h _i from the distance between the detected target and the i-th aircraft in accordance with the expression

$$\begin{array}{l}{h}_i=\frac{\mathrm{one}}{{\left(x_{\mathrm{one}}-x_i\right)}^2+{\left(y_{\mathrm{one}}-y_i\right)}^2+{\left(z_{\mathrm{one}}-z_i\right)}^2}\times \\ \times {\left(\frac{{\left(x_{\mathrm{one}}-x_i\right)}^2}{9\left(D\left[x_{\mathrm{one}}\right]-D\left[x_i\right]\right)}+\frac{{\left(y_{\mathrm{one}}-y_i\right)}^2}{9\left(D\left[y_{\mathrm{one}}\right]-D\left[y_i\right]\right)}+\frac{{\left(z_{\mathrm{one}}-z_i\right)}^2}{9\left(D\left[z_{\mathrm{one}}\right]-D\left[z_i\right]\right)}\right)}^{\frac{\mathrm{one}}{2}}\left(8\right)\end{array}$$

- the formation of a decision on the coincidence or mismatch of the spatial coordinates of the detected air target and the i-th aircraft according to the Neumann-Pearson criterion in accordance with the expression

where the hypothesis χ _i = 1 - the spatial coordinates of the detected air target and the i-th aircraft coincide, that is, the i-th aircraft is the air target detected by the airborne radar of the requesting aircraft, the hypothesis χ _i = 0 - the spatial coordinates of the detected air target and the i-th aircraft does not match, the i-th aircraft is not the target detected by the airborne radar of the requesting aircraft;

- the formation and transmission of the encoded response signal using an aircraft radar transponder in the case of a decision on the coincidence of the spatial coordinates of the detected air target and the i-th aircraft.

;

;

.This ensures a reduction in the volume of uncertainty of the RSAO to the size of an ellipse with half shafts

;

;

.

3. On the side of the requesting aircraft, the response signal is received and processed, as well as a decision is made on the identification sign of the target by the aircraft radar interrogator in accordance with the existing identification method.

This method can be implemented, for example, using a device whose structural diagram is shown in figure 1, where it is indicated: 1 - requesting aircraft, 2 - information processing unit, 3 - navigation system, 4 - synchronizer, 5 - aircraft radar interrogator, 6 - airborne radar, 7 - requested aircraft, 8 - aircraft radar transponder, 9 - information processing unit, 10 - synchronizer, 11 - navigation system.

The information processing unit 2 is designed to process information coming from the navigation system 3 and the airborne radar 6 in accordance with the expressions (1-6). Navigation system 3 is designed to generate estimates of the Cartesian coordinates of the location of the requesting aircraft 1 X ₀ = [x ₀ , y ₀ , z ₀ ] ^T and the angular coordinates characterizing its spatial orientation W ₀ = [ψ ₀ , ϑ ₀ , γ ₀ ] ^T in a relative coordinate system with the corresponding variances D [X ₀ ] and D [W ₀ ]. The synchronizer 4 is designed to synchronize the operation of the elements of the device on board the requesting aircraft 1. Aircraft radar interrogator 5 is designed to generate and transmit an encoded request signal with information about the estimates of the Cartesian coordinates of the detected air target X ₁ in the relative coordinate system and the corresponding variances D [X ₁ ] , to receive and process the encoded response signal transmitted from the requested aircraft, as well as to form a decision on identification On the basis of an air target in accordance with the existing method of identification. Airborne radar 6 is designed to detect an air target and generate estimates of its polar coordinates J ₁ = [D ₁ , α ₁ , β ₁ ] ^T in a connected coordinate system with the corresponding dispersions D [J ₁ ]. Aircraft radar transponder is designed to receive and process the encoded request signal transmitted from the board of the requesting aircraft 1, with the release of information about the spatial coordinates of the detected air target X ₁ in the relative coordinate system and the corresponding dispersions D [X ₁ ], as well as for generation and transmission encoded response signal, in the case of a decision made in the information processing unit 9 about the coincidence of the spatial coordinates of the detected air target and the requested air th vessel 7. The information processing unit 9 for processing information received from aircraft radar transponder 8 and the navigation system 11 in accordance with the expressions (7-9). The synchronizer 10 is designed to synchronize the operation of the device elements on board the requested aircraft 7. The navigation system 11 is designed to generate estimates of the Cartesian coordinates of the location of the i-th aircraft 7 X _i = [x _i , y _i , z _i ] ^T in the relative coordinate system and corresponding dispersions D [X _i ].

. С выхода навигационной системы 11 на вход блока обработки информации 9 поступают оценки декартовых координат местоположения i-го воздушного судна 7 X_i=[x_i,y_i,z_i]^T в относительной системе координат с соответствующими дисперсиями D[X_i]. Блок обработки информации 9 обрабатывает информацию, поступившую с выходов самолетного радиолокационного ответчика 8 и навигационной системы 11 в соответствии с выражениями (7-9). С выхода блока обработки информации 9 на вход самолетного радиолокационного ответчика 8 поступает информация о совпадении или несовпадении пространственных координат обнаруженной воздушной цели и i-го воздушного судна 7. Самолетный радиолокационный ответчик формирует и передает кодированный ответный сигнал, в случае принятого решения в блоке обработки информации 9 о совпадении пространственных координат обнаруженной воздушной цели и i-го воздушного судна 7. Самолетный радиолокационный запросчик 5 принимает и обрабатывает кодированный ответный сигнал, переданный с борта запрашиваемого воздушного судна 7, а также формирует решение об идентификационном признаке воздушной цели в соответствии с существующим способом идентификации.The device operates as follows. The synchronizer 4 synchronizes the operation of the elements of the device on board the requesting aircraft. The on-board radar 6 detects an air target and generates estimates of its polar coordinates J ₁ = [D ₁ , α ₁ , β ₁ ] ^T in the associated coordinate system with the corresponding dispersions D [J ₁ ]. From the output of the airborne radar 6 to the input of the information processing unit 2, estimates of the polar coordinates of the detected air target J ₁ = [D ₁ , α ₁ , β ₁ ] ^T in the associated coordinate system with the corresponding dispersions D [J ₁ ] are received. Navigation system 3 generates estimates of the Cartesian coordinates of the location of the requesting aircraft X ₀ = [x ₀ , y ₀ , z ₀ ] ^T and the angular coordinates W ₀ = [ψ ₀ , ϑ ₀ , γ ₀ ] ^T , characterizing its spatial orientation in the relative system coordinates with the corresponding variances D [X ₀ ] and D [W ₀ ]. From the output of the navigation system 3, the input of the information processing unit 2 receives estimates of the Cartesian coordinates of the location of the requesting aircraft X ₀ = [x ₀ , y ₀ , z ₀ ] ^T and angular coordinates W ₀ = [ψ ₀ , ϑ ₀ , γ ₀ ] ^T characterizing its spatial orientation in a relative coordinate system with the corresponding variances D [X ₀ ] and D [W ₀ ]. The information processing unit 2 processes the information received from the navigation system 3 and the airborne radar 6 in accordance with the expressions (1-6). From the output of the information processing unit 2, the information on the estimates of the Cartesian coordinates of the detected air target X ₁ in the relative coordinate system and the corresponding dispersions D [X ₁ ] is received at the input of the aircraft radar interrogator 5. Aircraft radar interrogator 5 generates and transmits an encoded interrogation signal with information about the estimates of the Cartesian coordinates of the detected air target X ₁ and the corresponding dispersions D [X ₁ ]. The synchronizer 10 synchronizes the operation of the device elements on board the i-th aircraft 7. Aircraft radar transponder 8 receives and processes the encoded request signal transmitted from the board of the requesting aircraft 1, with the release of information about the estimates of the Cartesian coordinates of the detected air target X ₁ in the relative coordinate system and the corresponding variances D [X ₁ ]. From the output of the aircraft radar transponder 8, information on estimates of the Cartesian coordinates of the detected air target X ₁ in the relative coordinate system and the corresponding dispersions D [X ₁ ] is received at the input of the information processing unit 9. The navigation system 11 generates estimates of the Cartesian coordinates of the location of the i-th aircraft 7 X _i = [x _i , y _i , z _i ] ^T in the relative coordinate system with the corresponding variances

. From the output of the navigation system 11 to the input of the information processing unit 9, estimates of the Cartesian coordinates of the location of the i-th aircraft 7 X _i = [x _i , y _i , z _i ] ^T in the relative coordinate system with the corresponding dispersions D [X _i ] are received. The information processing unit 9 processes the information received from the outputs of the aircraft radar transponder 8 and the navigation system 11 in accordance with expressions (7-9). From the output of the information processing unit 9, the input of the aircraft radar transponder 8 receives information about the coincidence or mismatch of the spatial coordinates of the detected air target and the i-th aircraft 7. The airborne radar transponder generates and transmits an encoded response signal, if the decision is made in the information processing unit 9 about the coincidence of the spatial coordinates of the detected air target and the i-th aircraft 7. Aircraft radar interrogator 5 receives and processes the encoded the response signal transmitted from the requested aircraft 7, and also forms a decision on the identification sign of the air target in accordance with the existing identification method.

To determine the effectiveness of the proposed method, the following indicators were evaluated:

- the probability of correct identification of the detected air target using the proposed method P _pi ;

- the probability of correct identification of the detected air target using the existing method (prototype) (see, for example, Radar systems of multifunctional aircraft. T. 1. Radar - information basis of military operations of multifunctional aircraft. Systems and algorithms for the primary processing of radar signals. / Ed. A.I. Kanaschenkova and V.I. Merkulov. - M.: “Radio Engineering”, 2006. S. 656) P _pi0 .

The indicators P _pi and P _pi0 were estimated by conducting statistical tests on the corresponding simulation models of a radar system with an active response under the same initial conditions.

To characterize the effectiveness of the proposed method, the increase in the probability of correct identification of air targets in the radar system with an active response was determined by applying the proposed method with respect to this indicator of the existing method (prototype) ΔP = P _pi -P _pi0 .

, а график 2 - значению

.Figure 2 shows graphs of the dependence of ΔP on the range to an air target D _c (km) detected by the airborne radar for various values of the spatial densities of air targets ρ. In this case, graph 1 corresponds to the spatial density of airborne objects

, and graph 2 - value

.

на дальности до воздушного объекта, обнаруженного бортовой РЛС, равной Д_ц=100 км, прирост вероятности правильной идентификации составляет ΔP≈0,05, в то время как для

, при прочих равных условиях прирост вероятности правильной идентификации составляет ΔP≈0,32.From the analysis of the graphs shown in figure 2 shows that the application of the proposed method leads to a significant increase in the probability of the correct identification of air targets in a multi-purpose environment. In this case, the greatest positive effect is achieved at higher spatial densities of airborne objects. So, for example, for

at a distance to an airborne object detected by an airborne radar equal to D _c = 100 km, the increase in the probability of correct identification is ΔP≈0.05, while for

, ceteris paribus, the increase in the probability of correct identification is ΔP≈0.32.

The proposed technical solution is new, because from publicly available information there is no known method for identifying air targets using the selection of the query signal by their spatial coordinates.

The proposed technical solution has an inventive step, since it does not explicitly follow from published scientific data and known technical solutions that the use of query signal selection by the spatial coordinates of an detected air target increases the likelihood of correct identification of aircraft.

The proposed technical solution is industrially applicable, since for its implementation elements that are widespread in the field of electronic and electrical engineering can be used.

Claims (1)

A method for identifying air targets based on detecting an air target using an onboard radar on the side of the requesting aircraft, generating and transmitting the encoded request signal by the aircraft radar interrogator, receiving and processing this request signal by the aircraft radar transponder on the side of each i-th aircraft, where

, I - the number of aircraft in the coverage area of the aircraft radar interrogator, having on board the aircraft radar transponder, the formation and transmission of the encoded response signal by the aircraft radar transponder from the side of each i-th aircraft, the reception and processing of data response signals, as well as the formation of decisions on the identification mark of an air target by an aircraft radar interrogator, characterized in that on the side of the requesting aircraft, estimates are generated the mouth coordinates of the detected air target and the corresponding variances in the relative coordinate system, encode the request signal with information containing estimates of the Cartesian coordinates of the detected air target in the relative coordinate system and the corresponding variances on the side of each i-th aircraft, the estimates of the Cartesian coordinates of the detected target in the relative coordinate system and the corresponding variance from the navigation system of each i-th aircraft in odyat assess its Cartesian coordinates and the respective dispersions are evaluated distance R _i between the detected air end and i-th aircraft determine h _i threshold value by the distance between the detected air end and i-th aircraft if R _i <h _i, then form a decision on the coincidence of the spatial coordinates of the detected air target and the i-th aircraft and transmit a response signal, otherwise the response signal is not transmitted.

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