KR101509121B1 - Method and Apparatus for controlling Side Lobe Canceller and Adaptive Beam Forming intelligently - Google Patents

Abstract

The present invention relates to a radar system, more particularly, to a method and a device for intelligently controlling side lobe cancel and adaptive beam forming in a radar system. According to the present invention, the angle tracing is well performed because a stand-off jammer is recognized as an active noise jammer and the neighboring general targets in the vicinity can be traced by not being affected by jammers. The method for intelligently controlling side lobe cancel and adaptive beam forming in a radar system includes: a step of checking if a current beam which is to be radiated is an active noise jammer (ANJ) tracing beam or not; a step of calculating a location of a group of first ANJs if the current beam which is to be radiated is not a tracing beam; a step of selecting ANJs existing on antenna side lobes in the group of first ANJs and storing the selected ANJs to a group of second ANJs; a step of calculating a jammer to noise ratio of the group of second ANJs; a step of checking if ANJs, among the group of second ANJs, of which jammer to noise ratio exceeds a predetermined threshold exist or not; a step of turning on a side lobe cancel function and a beam forming function if ANJs of which jammer to noise ratio exceeds the predetermined threshold value exist as a result of the checking; and a step of turning off the side lobe cancel function and beam forming function if ANJs of which jammer to noise ratio exceeds the predetermined threshold value do not exist as a result of the checking.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and an apparatus for intelligently controlling a side lobe removal and an adaptive beam forming of a radar system,

The present invention relates to radar system technology, and more particularly to a method and apparatus for intelligently controlling a side lobe removal or adaptive beam forming technique in a radar system.

During war, radars must detect and / or track targets in various jamming environments. In particular, strong noise jamming of stand-off jammer (SOJ) and self-screen jammer (SSJ) has a serious effect on radar operation, so radar must take measures against it do.

Usually, to cope with such noise jamming, the radar uses a side lobe canceller (SLC) or adaptive beam forming (ABF) technique.

This technique is a technique for detecting and / or tracking a target signal by removing a noise jamming signal. However, it is important to use this technology intelligently and appropriately in a variety of jamming environments.

When there are various jammers, jammers sometimes jam to increase the jamming effect and sometimes do not. And this jamming may or may not affect the detection and tracking of current targets. Also, jammers must also be detected and / or tracked to know the location of the jammers in order to respond to the jammers.

At this time, there is a problem in that jammer can not be detected and tracked by applying the side lobe removal and adaptive beam forming technology. Therefore, the technique of removing jamming can not be applied to all situations. Thus, intelligent control of sidelobe removal or adaptive beam forming techniques is required.

In addition, when there is no influence of jammers, applying side lobes and adaptive beam forming can affect the antenna pattern. A diagram showing this is shown in Fig. The red in FIG. 1 is the antenna pattern when the side lobes are removed and the adaptive beam forming is not applied in the absence of jammers, and the remaining colors are the antenna patterns when the side lobes are removed and the adaptive beam forming is applied in the absence of jammers.

As shown in FIG. 1, when the side lobes are removed and adaptive beam forming is applied, the side lobe of the antenna pattern changes according to the situation and the level rises.

However, when the level of the side lobe of the antenna pattern is increased, the radar detection performance is deteriorated because it is vulnerable to the clutter environment of the mountainous terrain of Korea. Therefore, it is required to apply the side lobe removal and adaptive beam forming technology only when there is jammer influence.

1. Korean Patent Publication No. 10-2007-0016394

1. Hong, Donghee, et al., "Implementation and Performance Analysis of Adaptive Beamformer using Subarray Synthesis", Journal of the Institute of Electronics, Information and Communication Engineers, Vol. 24, No. 4, 2013.4, 448-458

The present invention provides a method and apparatus for intelligently controlling the removal of side lobes and the adaptive beam forming of a radar system that maintains radar detection performance in a mountainous terrain environment. have.

It is another object of the present invention to provide a method and apparatus for intelligently controlling a side-lobe removal and an adaptive beamforming of a radar system selectively applying a side lobe removal and adaptive beam forming technique only when there is an influence of jammers.

SUMMARY OF THE INVENTION The present invention provides a method for intelligently controlling a sidelobe removal and adaptive beamforming of a radar system that maintains radar detection performance in a mountainous terrain environment in order to accomplish the above problems.

A method for intelligently controlling a side lobe removal and adaptive beamforming of the radar system,

Confirming whether the current beam to be emitted is an active noise jammer (ANJ) tracking beam;

Calculating a position of the first set of active noise jammers if the result is not an active noise jammer tracking beam;

Selecting one of the first set of active noise jammers and storing the active noise jammers in the second set of active noise jammers;

Calculating a jammer-to-noise ratio of the set of second active noise jammers;

Determining whether there is an active noise jammer in the set of the second active noise jammers exceeding a predetermined threshold value of the jammer-to-noise ratio;

A step of turning on the side lobe removing function and the beam forming function when there is an active noise jammer having a jammer-to-noise ratio exceeding a preset threshold value; And

And turning off the side lobe removing function and the beam forming function when there is no active noise jammer exceeding a predetermined threshold value of the jammer-to-noise ratio.

In this case, the first set of active noise jammers may be a set of active noise jammers managed by the control unit.

In addition, the second set of active noise jammers may be a set of active noise jammers existing in the antenna side lobe.

Also, the calculation of the position of the first set of active noise jammers may be a position at the time of emitting the current beam.

Also, the calculation of the jammer-to-noise ratio may be performed in consideration of the antenna side level.

In addition, the location equation P _prediction = P _before + V and dT (where, P _prediction is in the set {ANJ} of the first active noise jammers in time for emitting the current beam position vector and, P _before the previous track Is the position vector of {ANJ} measured by the beam, V is the velocity vector of {ANJ}, dT is the difference between the time of emitting the current beam and the time of measuring {ANJ} with the previous tracking beam .

In addition, the presence or absence of an antenna lobe is Equation _{(| U - U ANJ |>} C 1 and _{BW U) ∪ (| V -} V ANJ |> C 2 and BW _V) (wherein, U, V are in the antenna coordinate system Where U _ANJ and V _ANJ are the angles of the active noise jammer in the antenna coordinate system BW _U and BW _V are the beam widths of U and V in the antenna coordinate system C ₁ and C ₂ are the scale values ) Is calculated using the following equation.

The jammer-to-noise ratio can be expressed by the following equation: JNR [dB] = P _Jammer + SideLobeLevel - P _Noise where P _Jammer is the power of {ANJ} _e , SideLobeLevel is the set of second active noise jammers ANJ} _e , and P _Noise is a noise level measured in advance for each waveform).

The P _Jammer calculates the square by averaging the amplitudes of the measured values in the distance-velocity tracking gate in the signal processing unit when tracking {ANJ} _e .

And calculating the position of {ANJ} _e in the reception beam pattern of the radiation of the current beam of the antenna coordinate system.

On the other hand, another embodiment of the present invention confirms that the current beam to be emitted is an active noise jammer (ANJ) tracking beam and calculates the position of the first set of active noise jammers Selecting a plurality of active noise jammers existing in an antenna sub-tile among the first set of active noise jammers and storing the selected ones in a second set of active noise jammers, calculating a jammer-to-noise ratio of the set of second active noise jammers, A controller for controlling the side lobes removing function and the beam forming function by checking whether there is an active noise jammer exceeding a predetermined threshold value of the jammer-to-noise ratio among the set of the second active noise jamers; And a signal processing unit for turning on or off the sidelobe removing function and the beam forming function under the control of the control unit. The intelligent control of the sidelobe removal and the adaptive beam forming in the radar system Device.

According to the present invention, a far-field jammer is recognized as an active noise jammer so that angle tracking is performed well, and the surrounding general target can be tracked without being affected by jammers.

Another advantage of the present invention is that the control of the side lobes removal and the adaptive beam formation operate intelligently because the remote obstruction device and the general target can be detected and tracked at the same time.

Another advantage of the present invention is that even when the jammer-to-noise ratio of a far-field jammer is larger than the signal-to-noise ratio of a general target, detection and tracking of a general target can be performed well.

1 is a graph showing the influence of side lobes removal and adaptive beamforming on an antenna pattern in the absence of a jammer in general.
2 is a conceptual diagram of a control device 200 including a control unit 210 and a signal processing unit 220 according to an embodiment of the present invention.
FIG. 3 is a configuration diagram of the signal processing unit 220 shown in FIG.
4 is a configuration diagram of the control unit 210 shown in FIG.
FIG. 5 is a flowchart of a side lobe removal and adaptive beamforming control according to an embodiment of the present invention.
6 is a conceptual diagram for obtaining a SideLobeLevel according to an embodiment of the present invention.
7 is a graph showing test results (detection and tracking of self-defense jammer) in accordance with an embodiment of the present invention.
Figure 8 is a graph showing test results (target detection and tracking in a far-reach jammer environment) in accordance with an embodiment of the present invention.
Figure 9 is a graph showing the test results (target detection and tracking in a number of far-air jammer environments) in accordance with 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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

2 is a conceptual diagram of a control device 200 including a control unit 210 and a signal processing unit 220 according to an embodiment of the present invention. 2, the control unit 210 transmits an intelligent decision command to the signal processing unit 220 in various noise jamming environments, and the signal processing unit 220 performs side removal and adaptive beamforming according to the command .

The controller 210 detects and tracks a far-field jammer or a self-protection jammer with an active noise jammer (ANJ) to cope with various noise jamming environments.

FIG. 3 is a configuration diagram of the signal processing unit 220 shown in FIG. Referring to FIG. 3, the signal processing unit 220 includes a sidelobe removal function unit 310 for performing sidelobe removal and an adaptive beamforming function unit 320 for performing adaptive beamforming.

4 is a configuration diagram of the control unit 210 shown in FIG. 4, the control unit 210 includes a beam request unit 410 that requests various beams of a radar (not shown) and a data processing unit that processes signal processed data received from the signal processing unit 220 420). In particular, the data processing unit 420 manages the data of the targets and jammers to be detected and / or tracked.

FIG. 5 is a flowchart of a side lobe removal and adaptive beamforming control according to an embodiment of the present invention. A method for intelligently controlling the side lobes removal and adaptive beamforming of a radar system (not shown) according to an embodiment of the present invention is a technique applied before emitting all beams, such as a detection beam and a tracking beam.

Referring to FIG. 5, first, when the current beam is emitted, it is confirmed whether the current beam is an active noise jammer (ANJ) tracking beam that tracks the active noise jammer (step S510).

In step S510, if the active noise jammer tracking beam traces the active noise jammer, the side lobe removal and adaptive beam forming functions are not used (OFF) (step S511).

Otherwise, in step S510, if the active noise jammer tracking beam is not the active noise jammer tracking result, the position of {ANJ} at the time of emitting the current beam is calculated. Here, {ANJ} is a set of active noise jammers managed by the control unit (210 in FIG. 2). The location can be obtained using the following formula.

Here, P _prediction is a position vector of {ANJ} at the time of emitting the current beam, and P _before is a position vector of {ANJ} measured by the previous tracking beam. V is the velocity vector of {ANJ}, dT is the difference between the time of emitting the current beam and the time of measuring {ANJ} with the previous tracking beam.

When the position calculation of {ANJ} is completed, the active noise jammer existing in the antenna side leaf of {ANJ} is selected and stored in {ANJ} _e (step S530). Here, {ANJ} _e represents a set of active noise jammers existing in the antenna side of the set of active noise jammers managed by the control unit.

The presence or absence of the antenna side lobe can be calculated using the following equation. That is, if the above condition is satisfied, it is determined that the antenna exists in the antenna side lobe.

Where U and V are the angles of the current beam in the antenna coordinate system and U _ANJ and V _ANJ are the angles of the active noise jammer in the antenna coordinate system. BW _U and BW _V are the beam widths of U and V in the antenna coordinate system. C ₁ and C ₂ are scale values.

The Jammer to Noise Ratio (JNR) of {ANJ} _e at the current beam position is calculated in consideration of the antenna side level (step S540). The calculation can be made using the following equation.

Where P _Jammer is the power of {ANJ} _e , SideLobeLevel is the side lobe level at the {ANJ} _e position in the current receive beam pattern, and P _Noise is the noise level previously measured for each waveform. The unit of this noise level is dB.

In addition, P _Jammer can obtain the amplitudes of the measured values in the distance-velocity tracking gate in the signal processing unit (220 in FIG. 2) by squaring the average when tracking {ANJ} _e . And SideLobeLevel can be easily understood from FIG. 6 is a conceptual diagram for obtaining a SideLobeLevel according to an embodiment of the present invention. 6 will be described later.

Continuing with reference to FIG. 5, it can be easily found by knowing the position of {ANJ} _e in the reception beam pattern of the current beam radiation in the antenna coordinate system.

As the jammer-to-noise ratio is calculated, if there is an active noise jammer exceeding the threshold value of the jammer-to-noise ratio of {ANJ} _e among the {ANJ} _{e, the use} of the side lobe removal (SLC) function and the adaptive beamforming (OFF) command is not used (steps S550, S560, S511). Whether the jammer-to-noise ratio (JNR) exceeds or exceeds the threshold value can be determined by the following equation.

Where JNR is the jammer-to-noise ratio of {ANJ} _e , and C ₃ is the threshold.

If there is an active noise jammer exceeding the predetermined threshold value in step S550, the SBC function and the adaptive beamforming function (ABF) are turned on (step S560).

Otherwise, if there is an active noise jammer in which the jammer-to-noise ratio exceeds a predetermined threshold value, the Sidelobe Removal (SLC) function and the Adaptive Beamforming (ABF) function are turned off in step S511.

6 is a conceptual diagram for obtaining a SideLobeLevel according to an embodiment of the present invention. Referring to FIG. 6, SideLobeLevel is a distance difference from the jammer's position 610 to the current beam's radial position 620.

7 is a graph showing test results (detection and tracking of self-defense jammer) in accordance with an embodiment of the present invention. Particularly, Fig. 7 shows the result of detection and tracking test of self-protection radio wave interrupter. Referring to FIG. 7, the upper part shows azimuth-distance (Az-R), and a self-screen jammer (SSJ) is recognized as an active noise jammer, . In FIG. 7, the red * indicates that it is an active noise jammer (ANJ).

In the lower part of FIG. 7, the time-SNR, time-range error, and time-azimuth error time of the self-shielding jammer (SSJ) -Azimuth Error, and Time-Elevation Error.

Figure 8 is a graph showing test results (target detection and tracking in a far-reach jammer environment) in accordance with an embodiment of the present invention. In particular, Figure 8 is a test result for detecting and tracking a target in a far-field jammer environment. The upper part of FIG. 8 represents azimuth-distance (Az-R), and a stand-off jammer (SOJ) is recognized as an active noise jammer so that angle tracking is performed well. You can see that it is tracked well without being affected.

The simultaneous detection and tracking of the SOJ and the general target means that the control of the side lobes and the adaptive beam formation operate intelligently.

8 shows the time-SNR, the time-range error, and the time-azimuth error of the general radio target SOJ and the general target, respectively. , And time-elevation error.

The red * mark is a disturbance interrupter recognized as an active noise jammer. The detection and tracking of the general target can be seen even when the jammer-to-noise ratio of the far-field jammer is larger than the signal-to-noise ratio of the normal target.

Figure 9 is a graph showing the test results (target detection and tracking in a number of far-air jammer environments) in accordance with an embodiment of the present invention.

200: Control device
210:
220: Signal processor
310: side lobe removal function part
320: Application Beam Forming Function
410: beam request unit
420:

Claims (9)

Confirming whether the current beam to be emitted is an active noise jammer (ANJ) tracking beam;
Calculating a position of the first set of active noise jammers if the active noise jammer tracking beam is detected;
Selecting one of the first set of active noise jammers and storing the active noise jammers in the second set of active noise jammers;
Calculating a jammer-to-noise ratio of the set of second active noise jammers;
Determining whether there is an active noise jammer in the set of the second active noise jammers exceeding a predetermined threshold value of the jammer-to-noise ratio;
A step of turning on the side lobe removing function and the beam forming function when there is an active noise jammer having a jammer-to-noise ratio exceeding a preset threshold value; And
Turning off the side lobe removing function and the beam forming function when there is no active noise jammer exceeding the predetermined threshold value of the jammer-to-noise ratio;
Wherein the radar system includes a plurality of sub-lobes, and the sub-lobes of the radar system and the adaptive beamforming are intelligently controlled.
The method according to claim 1,
Wherein the set of first active noise jammers is a set of active noise jammers managed by a control unit and the set of second active noise jammers is a set of active noise jammers existing in an antenna side lobe. And intelligent control of adaptive beamforming.
The method according to claim 1,
Wherein the calculation of the position of the first set of active noise jammers is a position at a moment when the current beam is emitted,
Wherein the calculation of the jammer-to-noise ratio is performed in consideration of the level of the antenna side lobes, and the method of intelligently controlling the side lobe removal and adaptive beam forming of the radar system.
The method according to claim 1,
The location is the equation P _prediction = P _before + V and dT (where, P _prediction is the position of the set {ANJ} of the first active noise jammers in time to emit a current beam vector, P _before the previous track beam Is the position vector of the measured {ANJ}, V is the velocity vector of {ANJ}, dT is the difference between the time of emitting the current beam and the time of measuring {ANJ} as the previous tracking beam A method for intelligently controlling a side lobe removal and adaptive beamforming of a radar system.
The method according to claim 1,
The existence or nonexistence of the antenna side lobes is expressed by the following equation (U - U _ANJ | C ₁ BW _U ) ∪ (| V - V _ANJ | C _{2 .BW V} ) U _ANJ and V _ANJ are the angles of the active noise jammer in the antenna coordinate system BW _U and BW _V are the beam widths of U and V in the antenna coordinate system C ₁ and C ₂ are the scale values) Wherein the radar system includes a plurality of radar systems,
The method according to claim 1,
The jammer-to-noise ratio is given by the equation JNR [dB] = P _Jammer + SideLobeLevel - P _Noise
(Wherein, of P _Jammer is the power of _{{ANJ} e, {ANJ}} e is the set of active noise jammers present in the antenna lobe of the set of active noise jammers, SideLobeLevel the second active noise jammers in the current reception beam pattern Wherein the noise level is calculated using a noise level of the set {ANJ} _e where P _Noise is a pre-measured noise level for each waveform.
The method according to claim 6,
The P _Jammer is {ANJ} _e the time to track distance of the signal processing-speed each amplitude of the measured value in the track gate (Amplitude) the side lobe removal of a radar system characterized in that calculated as the square of the mean, and Adaptive Beamforming ≪ / RTI >
The method according to claim 6,
Wherein the jammer-to-noise ratio is calculated using the location of {ANJ} _e in the receive beam pattern of radiation of the current beam in the antenna coordinate system.
(EN) An active noise jammer tracking beam is generated. The first active noise jammer is set to be an active noise jammer tracking beam. To-noise ratios of the second set of active noise jammers are calculated, and the jammer-to-noise ratios of the second set of active noise jammers are calculated A controller for checking whether there is an active noise jammer exceeding a preset threshold value and controlling the side lobe removing function and the beam forming function; And
And a signal processing unit for turning on or off the sidelobe removing function and the beam forming function under the control of the control unit. The apparatus for intelligently controlling the sidelobe removal and the adaptive beam forming of a radar system, .

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