KR20160039473A - Joint direction of departure and direction of arrival estimation method and apparatus using steering vector manipulation in bistatic radar with jammer discrimination - Google Patents

Abstract

The present invention relates to technology for processing radar signals. More particularly, the present invention relates to an apparatus and a method for distinguishing DOA (direction of arrival) due to a jammer in a bistatic radar environment and estimating target DOA and DOD (direction of departure). According to the present invention, in the bistatic radar environment having the jammer and an arbitrary 2D or 1D antenna arrangement, the DOA due to a target from a receiving signal is discriminated from the DOA due to the jammer. The method comprises: an input step; an estimation DOA generation step; a DOD estimating step; and an information obtaining step.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for estimating a target DOD-DOA using a steering vector operation capable of discriminating jammers, and a method and an apparatus for estimating a target DOD-

Field of the Invention [0002] The present invention relates to a radar signal processing technique, and more particularly, to a method and apparatus for distinguishing a direction of arrival (DOA) caused by jammers in a bistatic radar environment and estimating a target DOA and a direction of departure .

 A bistatic radar system utilizes spatial diversity as a system where the transmitting and receiving radar platforms are physically spaced apart. Therefore, it is more suitable for detection of low-fat fleet such as stealth fighter by improving target detection possibility and position accuracy compared with mono static system.

However, in such a bi-static system, the DOD (Direction Of Departure) which views the target at the transmitting end and the DOA (Direction Of Arrival) information which sees the target at the receiving end are used to find out the position of the target, And DOA together.

Therefore, it is difficult to perform additional signal processing for pairing DOA and DOD pair matching each target when there are plural targets.

Furthermore, when the enemy uses jammers to reduce the radar performance of the allied forces, there is a distinction between the estimated DOA and the jammer. In order to obtain accurate target information, a technique of distinguishing the target DOA from the jammer DOA is required.

1. Korean Patent Publication No. 10-2013-0100059 2. Korean Patent No. 101068103 3. Korean Patent Publication No. 10-2007-0016394

1. Sung-Jin Lee et al., "Performance Analysis of Monostatic RCS and Bistatic RCS for Target Division", Journal of Korea Electromagnetic Engineering Society, Vol.21, No.12, December 2010, pp.1460-1466

The present invention has been proposed in order to solve the problem according to the above background art, and it is an object of the present invention to accurately discriminate a target DOA (Direction Of Arrival) by a target and a jammer DOA by a target in a bistatic radar environment, (DOA) -DOD (Direction Of Departure) estimation method and apparatus.

In order to achieve the above-mentioned object, in order to achieve the above-mentioned object, in order to accurately distinguish a target DOA (Direction Of Arrival) by a target in a bistatic radar environment and a jammer DOA by a jammer, a DOA- DOD Departure) estimation method.

The DOA-DOD estimation method of the above-

A reception signal input step in which the reception unit inputs a reception signal reflected from the target;

A matched filtering step of performing matched filtering to remove a signal component transmitted from a received signal input to the matched filter unit;

An estimated DOA generating step of generating estimated DOAs by applying a DOA estimation algorithm to a DOA (Direction Of Arrival) estimating additive filtered signal;

A new signal generation step in which the signal generation module generates new signals by the number of the estimated DOAs;

A DOD estimation step of estimating a DOD (Direction Of Departure) of the target by distinguishing a jammer-based jammer DOA from the estimated DOAs by applying an angle estimation algorithm to the new signals; And

And an information acquiring step of acquiring DOA and Direction Of Departure (DOD) information of the target using the jammer DOA.

In this case, the estimated DOD step may include: applying the angle estimation algorithm; Determining that the estimated DOAs are jammer DOAs if there is no estimated DOD; And determining that the estimated DOAs are a target DOA based on the target DOD if there is an estimated DOD as a result of the application.

Also, the information acquiring step may include acquiring DOA and DOD information of the target in which the jammer is distinguished by matching the estimated DOAs with the respective estimated DOs, except for the estimated DOAs in which the DOD information does not appear among the estimated DOAs Can be characterized.

Also, when the new signals are estimated using the target DOA by the target, the DOD that matches the target DOA is estimated, and when the new signals are estimated using the jammer DOA of the jammer, the DOD is not displayed have.

In addition, the estimated DOA may be a state in which the target DOA and the jammer DOA are estimated together without being distinguished from each other.

Also, the angle estimation algorithm may be MUSIC (MULTI SIIGNAL CLASSIFICATION).

The receiving unit may include a plurality of receiving array antennas, and the plurality of receiving array antennas may be arranged in a bistatic radar manner.

The information of the plurality of receiving array antennas may be expressed by a matrix using steering vector calculations.

On the other hand, another embodiment of the present invention includes a receiver for inputting a received signal reflected from a target; A matched filter unit for performing matched filtering to remove a signal component transmitted from a received signal; A DOA estimation unit for generating estimated DOAs by applying a DOA (Direction Of Arrival) estimation algorithm to the matched filtered signal; A signal generation module for generating new signals by the number of estimated DOAs; A DOD estimation module for applying an angle estimation algorithm to the new signals to distinguish the jammer DOA from the estimated DOAs to estimate a Direction Of Departure (DOD) of the target; And a DOD-DOA estimating device using a jammer distinguishable steering vector computation to obtain DOA and Direction Of Departure (DOD) information of the target using the jammer DOA do.

According to the present invention, it is possible to distinguish a target DOA (Direction Of Arrival) from a received signal in a bistatic radar environment in which a jammer exists and an arbitrary two-dimensional or one-dimensional antenna array and DOA due to jammers.

Further, as another effect of the present invention, it is possible to estimate the DOD (Direction Of Departure) of the target to be matched using the DOA of the distinguished target.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing an antenna arrangement having a general arbitrary two-dimensional arrangement. Fig.
Figure 2 shows an antenna arrangement with a general linear one-dimensional arrangement.
3 is a conceptual diagram showing a transmission / reception environment of a general bistatic radar system.
4 is a configuration diagram of a Direction Of Departure (DOD) -DOA (Direction Of Arrival) estimation apparatus according to an embodiment of the present invention.
5 is a flowchart illustrating a DOD-DOA estimation process according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

A Direction Of Departure (DOD) -DOA (Direction Of Arrival) estimation method and apparatus using a steering vector calculation capable of discriminating jammers according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings .

개인 안테나 배열이다. 이 경우 조향벡터는 다음의 수학식 1과 같은 형태로 표현된다.BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing an antenna arrangement having a general arbitrary two-dimensional arrangement. Fig. Referring to FIG. 1, the number of antennas 110 having an arbitrary two-dimensional array configuration is

It is a personal antenna array. In this case, the steering vector is expressed by the following equation (1).

[Equation 1]

,

이며,

는 표적 혹은 재머와 배열 안테나가 이루는 고 각도(elevation angle)이고,

는 방위각도(azimuth angle)를 나타낸다. 또한, 위첨자

는 전치(transpose) 연산을 의미한다.

는 첫 번째 안테나의 위치를 기준으로 한

번째 안테나의 위치이며

는 송신에 사용하는 캐리어의 파장을 의미한다.here,

,

Lt;

Is the elevation angle between the target or jammer and the array antenna,

Represents an azimuth angle. Also,

Means a transpose operation.

Is based on the position of the first antenna

Lt; th > antenna

Quot; means the wavelength of the carrier used for transmission.

Figure 2 shows an antenna arrangement with a general linear one-dimensional arrangement. Referring to FIG. 2, if the array of the antennas 210 is linear, the steering vector is expressed by the following equation.

&Quot; (2) "

는 선형 안테나 배열과 표적 혹은 재머가 이루는 각도이고,

는

과

번째 안테나 사이의 간격으로 그레이팅 로브(grating lobe)를 줄이기 위해

이상의 값을 갖는다. 수학식 1과 수학식 2로 표현되는 조향벡터는 다음 수학식 과 같은 관계를 갖는다.here

Is the angle between the linear antenna array and the target or jammer,

The

and

Lt; th > antennas to reduce the grating lobe

Or more. The steering vectors expressed by the equations (1) and (2) have the following relationship.

&Quot; (3) "

&Quot; (4) "

는 복소수 값으로

을 만족한다. 본 발명은 위에서 언급한 대로 2-D 또는 1-D 안테나 배열에 적용가능하나 이하에서는 선형 안테나 배열을 실시예로 들어 설명한다.here

Is a complex number.

. The present invention is applicable to a 2-D or 1-D antenna arrangement as mentioned above, but a linear antenna arrangement will be described below as an embodiment.

개의 제 1 내지 제 N 송신 배열 안테나(320-1 내지 320-N), 수신부(330)는

개의 제 1 내지 제 N 수신 배열 안테나(330-1 내지 330-N)로 구성된다. 3 is a conceptual diagram showing a transmission / reception environment of a general bistatic radar system. Referring to FIG. 3, the transmitter 320

First to Nth transmit array antennas 320-1 to 320-N, and a receiving unit 330

And first to Nth receiving array antennas 330-1 to 330-N.

개의 제 1 내지 제 k 포인트 표적(310-1 내지 310-k)이며, 재머(340)는

개(340-1 내지 340-l)를 가정한다. 송신부(320)의 제 1 내지 제 N 송신 배열 안테나들(320-1 내지 320-N)은 여러 개의 파형을 송신하는 MIMO(multiple input multiple output) 시스템으로 구성된다. The target 310

The first to k-th point targets 310-1 to 310-k, and the jammers 340

Assume the dogs 340-1 to 340-l. The first to Nth transmit array antennas 320-1 to 320-N of the transmitter 320 are composed of multiple input multiple output (MIMO) systems for transmitting a plurality of waveforms.

개의 스냅샷으로 이루어져 있고 다음의 수학식과 같이 표현된다.The received signal received by the receiver 330

And is represented by the following equation.

&Quot; (5) "

,

는 수신부 조향행렬,

는 레이더 반사 면적(RCS: Rader Cross Section) 응답에 비례하는 크기행렬, 는 송신부 조향행렬이다. here,

,

Is a receiver steering matrix,

Is a magnitude matrix proportional to the Radar Cross Section (RCS) response, Is the transmitter steering matrix.

와

는 각각 표적과 재머의 것을 의미하고, 위첨자

는 허미시안(herimitian) 연산을 의미한다. 송신신호

와 재머

그리고 잡음

는 서로 비상관 관계(uncorrelated)라 가정한다. Also,

Wow

Means the target and jammer, respectively, and the superscript

Means a herimitian operation. Transmission signal

And jammer

And noise

Are uncorrelated with each other.

, 재머 DOA가

, 표적의 DOD(Direction Of Departure)가

일 때 각 조향행렬은 다음 수학식과 같이 나타낼 수 있다.The steering matrix is a matrix having a steering vector of the equation (2) as a column, and the DOA (Direction Of Arrival) of the target 310

, Jammer DOA

, The target's Direction Of Departure (DOD)

The respective steering matrices can be expressed by the following mathematical expression.

&Quot; (6) "

Where B _T is the receive steering matrix corresponding to the target, B _J is the receive steering matrix corresponding to jammers, A _T is the transmit steering matrix corresponding to the target, a is the transmit steering vector, and b is the receive steering vector.

The size matrix is a diagonal matrix, and each component is proportional to the intensity of the RCS and jammers of each target and is expressed as:

&Quot; (7) "

을 제외한 표적의 DOD, DOA 쌍

이다.The information to be acquired in the reception signal of Equation (5) is the DOA

DOD, DOA pair of target except

to be.

Further, a matched filter is applied to remove a signal component transmitted from the reception signal of Equation (5). The output of the matched filter can be expressed by the following equation.

&Quot; (8) "

, 재머의 DOA

가 구별되지 않고 추정된다. 이 때 사용하는 알고리즘은 추정만 가능하다면 본 발명의 설명을 제한하지 않는다. 그 후 다음 수학식의 신호를 생성한다.When a DOA estimation algorithm such as MUSIC (MULTI SIIGNAL CLASSIFICATION) is applied to the signal of Equation (8), the target DOA

, Jammer's DOA

Are estimated without distinction. The algorithm used in this case does not limit the description of the present invention only if it can be estimated. Then, a signal of the following equation is generated.

&Quot; (9) "

)개이다. 수학식 3 및 수학식 4를 이용하여

에 대입된 DOA가 표적에 의한 표적 DOA이면 수학식 10, 재머에 의한 재머 DOA이면 수학식 11로 나타낼 수 있다.The number of generated signals of Equation (8) is the total number of estimated DOAs

). Using equations (3) and (4)

(10) for a target DOA by the target, and Equation (11) for a jammer DOA by the jammer.

&Quot; (10) "

&Quot; (11) "

The covariance matrices of Equation (10) and Equation (11) are as follows.

&Quot; (12) "

&Quot; (13) "

은 평균(expectation) 연산을 의미한다.here

Means an expectation operation.

가 포함된 항이다. 수학식 3 및 4의 관계에 따라

이므로 수학식 12의 첫 번째 항에서 송신 조향행렬

의 열 중 대입한 표적 DOA

에 대응되는

번째 열인

정보가 다른 조향벡터와 비교하여 큰 값을 갖는다. The first term of the three items constituting the equations (12) and (13) is the DOD information

. According to the relationship of Equations 3 and 4

Therefore, in the first term of Equation (12), the transmission steering matrix

Target DOA < / RTI >

Corresponding to

Th column

The information has a large value in comparison with other steering vectors.

In addition, since it is larger than the values of the second and third terms, only the DOD corresponding to the assigned DOA is estimated by applying an estimation algorithm such as MUSIC to this signal. Therefore, the DOA and DOD matching are automatically performed, and the additional signal processing for matching is omitted.

In Equation 13, which is the covariance matrix of the signal generated by substituting the jammer's jammer DOA, since the DOD information of the target is all small, the values of the second term and the third term are covered, and when the angle estimation algorithm is applied, It does not.

If there is no estimated angle information using the angle estimation algorithm in Equation 9, the DOA that is substituted into the signal generation of Equation 9 is judged as a jammer DOA by the jammer. If the DOD information is estimated, Equation 9 The DOA assigned to the signal generation of the target DOA is the target DOA, and the estimated angle information can be determined as the DOD of the target corresponding to the assigned DOA.

4 is a configuration diagram of a Direction Of Departure (DOD) -DOA (Direction Of Arrival) estimation apparatus according to an embodiment of the present invention. 4, the DOD-DOA estimating apparatus 400 includes a receiving unit 330, a matched filter unit 410, a DOA estimating unit (not shown) configured by first to Nth array antennas 330-1 to 330- 420, a signal generation module 430, a DOD estimation module 440, and an information acquisition unit 450.

The reception unit 330 performs a function of inputting a reception signal reflected from a target (310 in FIG. 3). The receiving unit 330 includes first to Nth receiving array antennas 330-1 to 330-N.

The matched filter unit 410 performs matched filtering to remove a signal component transmitted from a reception signal generated by the reception unit 330. The DOA estimation unit 420 receives a DOA (Direction Of Arrival) And estimating DOAs by applying the estimation algorithm.

The signal generation module 430 generates new signals by the number of the estimated DOAs. Accordingly, the first group of signal generators 431-1 to 431-k that generate signals related to the target and the second group of signal generators 432-1 to 432-k that generate signals related to jammers .

The DOD estimation module 440 estimates a direction of departure (DOD) of the target by distinguishing the jammer DOA from the estimated DOAs by applying an angle estimation algorithm to the new signals. For this purpose, the first group of DOD estimators 441-1 to 441-k for estimating the DOD related to the target and the second group of DOD estimators 442-1 to 442-k for estimating the DOD related to the jammers, .

The information acquisition unit 450 acquires DOA and Direction Of Departure (DOD) information of the target using the jammer DOA.

In other words, if the signal generated using the target DOA information is estimated, the DOD that matches the target DOA is estimated, and the angle information is not displayed when the signal using the jammer DOA information is estimated. If the remaining DOAs are matched with the respective estimated DODs except the DOA for which no DOD information is displayed, the jammer can acquire the DOA and DOD information of the distinguished target.

FIG. 5 is a flowchart illustrating a DOD (Direction Of Departure) -DOA (Direction Of Arrival) estimation process according to an embodiment of the present invention. In addition, FIG. 5 is a flowchart for explaining a DOA and DOD estimation process of a jam-distinguished target in the bistatic radar system. Referring to FIG. 5, a receiver (330 in FIG. 3) inputs a received signal reflected from the target 310 (step S510).

와 재머의 DOA

가 구별되지 않고 함께 추정된 상태이다.Thereafter, DOA estimation algorithm is applied to the matched-filtered reception signal of Equation (9) to estimate DOA (S520, S530). In this case, the estimated DOA is the target DOA

And Jammer's DOA

Are estimated together.

Then, new signals as shown in Equation (9) are generated by the number of estimated DOAs (Step S540).

When new signals are generated, an angle estimation algorithm such as MUSIC is applied to the generated signals (step S550).

Lastly, DOA by jammer is distinguished by using the result after applying the algorithm, and DOA and DOD information of the target are obtained (step S560).

It will be appreciated that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the design constraints and specific applications imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the exemplary embodiments of the present invention.

The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array Or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in a memory such as a random access memory (RAM), a flash memory, a read only memory (ROM), an electrically programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), registers, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. Alternatively, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored or transmitted as one or more instructions or code on a computer-readable medium. The computer-readable medium includes both a communication medium and a computer storage medium, including any medium that facilitates transfer of a computer program from one place to another. The storage medium may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can be stored in RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, And any other medium which can be used to carry or store the desired program code and which can be accessed by a computer.

Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a web site, server, or other remote source using wireless technologies such as coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or infrared, wireless and microwave, Wireless technologies such as cable, fiber optic cable, twisted pair, DSL, or infrared, radio, and microwave are included within the definition of media. As used herein, a disk and a disc include a compact disc (CD), a laser disc, an optical disc, a digital versatile disc (DVD), a floppy disc and a Blu-ray disc, Discs generally reproduce data magnetically, while discs use lasers to optically reproduce data. Also, the above combinations should be included within the scope of computer-readable media.

310: Target
320: transmitting unit 330: receiving unit
410: matched filter section
420: DOA (Direction Of Arrival) estimation unit
430: Signal Generation Module
440: Direction Of Departure (DOD) Estimation Module
450: Information obtaining unit

Claims (9)

A reception signal input step in which the reception unit inputs a reception signal reflected from the target;
A matched filtering step of performing matched filtering to remove a signal component transmitted from a received signal input to the matched filter unit;
An estimated DOA generating step of generating estimated DOAs by applying a DOA estimation algorithm to a DOA (Direction Of Arrival) estimating additive filtered signal;
A new signal generation step in which the signal generation module generates new signals by the number of the estimated DOAs;
A DOD estimation step of estimating a DOD (Direction Of Departure) of the target by distinguishing a jammer-based jammer DOA from the estimated DOAs by applying an angle estimation algorithm to the new signals; And
An information acquiring step of acquiring DOA and DOD (Direction Of Departure) information of the target using the jammer DOA;
And estimating the DOD-DOA of the target using the jammer-distinguishable steering vector computation.
The method according to claim 1,
The estimated DOD step includes:
Applying the angle estimation algorithm;
Determining that the estimated DOAs are jammer DOAs if there is no estimated DOD; And
And determining the estimated DOAs as a target DOA based on the target DOD if there is an estimated DOD as a result of applying the DOD-DOA estimation method to the DOD-DOA of the target using the jammer distinguishable steering vector calculation.
3. The method of claim 2,
The information acquiring step includes:
Characterized in that DOA and DOD information of a target in which jammers are distinguished is obtained by matching the estimated DOAs with respective estimated DOs except for the estimated DOAs in which the DOD information does not appear among the estimated DOAs, A method of estimating a DOD-DOA of a target using a vector operation.
3. The method of claim 2,
And estimating the new signals using the target DOA to estimate the DOD to match the target DOA and estimating the new signals using the jammer DOA of the jammer. -DOA estimation method.
The method according to claim 1,
Wherein the estimated DOA is a state in which the target DOA and the jammer DOA are not differentiated from each other and are estimated together.
The method according to claim 1,
Wherein the angle estimation algorithm is MUSIC (MULTI SIIGNAL CLASSIFICATION), wherein the jammer distinguishable steering vector calculation is used.
The method according to claim 1,
Wherein the receiving unit comprises a plurality of receiving array antennas and the plurality of receiving array antennas are arranged in a bi-static radar manner.
8. The method of claim 7,
Wherein the information of the plurality of receive array antennas is represented by a matrix using steering vector calculations.
A receiver for receiving a signal reflected from the target;
A matched filter unit for performing matched filtering to remove a signal component transmitted from a received signal;
A DOA estimation unit for generating estimated DOAs by applying a DOA (Direction Of Arrival) estimation algorithm to the matched filtered signal;
A signal generation module for generating new signals by the number of estimated DOAs;
A DOD estimation module for applying an angle estimation algorithm to the new signals to distinguish the jammer DOA from the estimated DOAs to estimate a Direction Of Departure (DOD) of the target; And
An information acquisition unit for acquiring DOA and Direction Of Departure (DOD) information of the target using the jammer DOA;
Wherein the target DOD-DOA estimator utilizes a jammer distinguishable steering vector calculation.

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