Digital array radar multi-beam receiving interference source angle measurement method and device

Abstract

The invention belongs to the technical field of airborne radar anti-interference, and particularly relates to a digital array radar multi-beam receiving interference source angle measurement method and device, and the method comprises the steps: S1, obtaining the wavelength, array element interval and array element number of a radar; s2, steering vectors are respectively generated by a plurality of equally-spaced angles, and equally-spaced wave beams pointed by the plurality of angles are formed; s3, determining a wave beam range corresponding to the maximum value of the interference power amplitude of the channel data in each wave beam; and S4, within the wave beam range, calculating an interference source angle by adopting a spatial spectrum estimation method. According to the interference source angle measurement method provided by the invention, the airspace scanning time can be reduced, the defects of high load calculation and time consumption of full-airspace spatial spectrum estimation can be avoided, and the interference source angle measurement precision can be effectively improved compared with a single-pulse angle measurement method.

Description

Technical Field

[0001] The present application belongs to the technical field of airborne radar anti-interference, and in particular relates to a method and device for measuring the angle of interference sources of a digital array radar multi-beam receiver. Background Art

[0002] As electromagnetic confrontations in modern warfare become increasingly fierce, the requirements for radar anti-interference performance are constantly increasing. Among them, fast and high-precision angle measurement of interference sources is particularly important. The angular measurement speed and accuracy of interference sources seriously affect the establishment, association and filtering of subsequent interference source target tracks, and are the key points affecting the entire radar anti-interference performance.

[0003] At present, airborne radars generally use conventional single pulse and difference beam angle measurement methods to measure the angle of interference sources. The advantages of this method are simple calculation and easy implementation, but the disadvantages are general accuracy and inability to measure the angle of interference sources that are not from the main lobe. Scanning the entire airspace to calculate the angle of the interference source will waste a lot of radar system resources. In addition, the use of spatial spectrum estimation methods (taking spatial MUSIC as an example) has the characteristics of high angle measurement accuracy but large calculation load and long time consumption compared to conventional single pulse and difference beam angle measurement methods. It is necessary to perform multiple iterative operations on the entire airspace to achieve accurate estimation of the angle of the interference source. The larger the airspace coverage, the higher the accuracy requirement, which will lead to a larger calculation load and longer time consumption. Summary of the invention

[0004] In order to solve the above problems, the present application provides a method and device for measuring the angle of interference sources for multi-beam reception of a digital array radar, which determines the interference space area through multi-beam reception and beam amplitude ratio judgment, solves the time-consuming problem of covering the entire airspace for sidelobe interference, and estimates the angle of the interference source in the spatial spectrum within the selected interference space area, solving the problems of general accuracy of conventional single-pulse angle measurement and large computational load and long time caused by spatial spectrum estimation of the entire airspace.

[0005] The first aspect of the present application provides a method for measuring the angle of a multi-beam receiving interference source of a digital array radar, which mainly includes:

[0006] Step S1, obtaining the wavelength, array element spacing and number of array elements of the radar;

[0007] Step S2, generating steering vectors from a plurality of equally spaced angles respectively, to form equally spaced beams pointed at a plurality of angles;

[0008] Step S3, determining the beam range corresponding to the maximum value of the interference power amplitude of each beam and channel data;

[0009] Step S4: within the beam range, using a spatial spectrum estimation method to calculate the interference source angle.

[0010] Preferably, in step S2, each angle θ is generated by the following formula: i The corresponding steering vector a(θ i ):

[0011]

[0012] Wherein, e represents the natural logarithm, j represents the imaginary number, κ=2π / λ represents the wave number, π represents the pi, λ represents the wavelength, M represents the number of array elements, and d represents the array element spacing.

[0013] Preferably, step S3 further comprises:

[0014] Step S31, digitally synthesizing the sum channel data of each beam;

[0015] Step S32, averaging the sum channel data of each beam, and obtaining the interference power amplitude of each beam by statistics;

[0016] Step S33, comparing the interfered power amplitudes of the various beams, and selecting the beam center with the largest interfered power amplitude;

[0017] Step S34: determine the beam range according to the beam center and the preset half beam width.

[0018] Preferably, step S4 further comprises:

[0019] Step S41, calculating the covariance matrix of the interference sample points within the beam range;

[0020] Step S42, determining the eigenvalue vector U corresponding to the maximum eigenvalue of the covariance matrix;

[0021] Step S43: Generate multiple scanning angle values ​​according to a preset step length within the beam range, and calculate each scanning angle value θ j The corresponding steering vector a(θ j );

[0022] Step S44: Generate each scanning angle value θ according to the following formula: j The corresponding spatial spectrum estimate P MUSIC (θ):

[0023]

[0024] Among them, a H (θ j ) is the steering vector a(θ j ), U H is the transposed matrix of the eigenvalue vector U;

[0025] Step S45: Select the scanning angle value that maximizes the spatial spectrum estimation value as the interference source angle measurement result.

[0026] The second aspect of the present application provides a digital array radar multi-beam receiving interference source angle measurement device, which mainly includes:

[0027] Radar parameter acquisition module, used to obtain the radar wavelength, array element spacing and number of array elements;

[0028] A beam forming module, used to generate steering vectors from multiple equally spaced angles to form equally spaced beams pointed at multiple angles;

[0029] A module for determining a beam range with a maximum interference power amplitude, used to determine a beam range corresponding to a maximum interference power amplitude in each beam and channel data;

[0030] The interference source angle calculation module is used to calculate the interference source angle within the beam range by using a spatial spectrum estimation method.

[0031] Preferably, in the beam forming module, each angle θ is generated by the following formula: i The corresponding steering vector a(θ i ):

[0032]

[0033] Wherein, e represents the natural logarithm, j represents the imaginary number, κ=2π / λ represents the wave number, π represents the circumference of a circle, λ represents the wavelength, M represents the number of array elements, and d represents the array element spacing.

[0034] Preferably, the interference power amplitude maximum beam range determination module includes:

[0035] A sum channel data calculation unit, used for digitally synthesizing the sum channel data of each beam;

[0036] The interference power amplitude statistical unit of each beam is used to average the sum channel data of each beam and obtain the interference power amplitude of each beam by statistics;

[0037] A beam center determination unit with the largest interference power amplitude, used to compare the interference power amplitudes of the various beams and select the beam center with the largest interference power amplitude;

[0038] The beam range determination unit is used to determine the beam range according to the beam center and a preset half beam width.

[0039] Preferably, the interference source angle calculation module includes:

[0040] A covariance matrix calculation unit, used to calculate the covariance matrix of the interference sample points within the beam range;

[0041] An eigenvalue vector determining unit, used to determine an eigenvalue vector U corresponding to the maximum eigenvalue of the covariance matrix;

[0042] A scanning angle value steering vector calculation unit is used to generate multiple scanning angle values ​​according to a preset step size within the beam range, and calculate each scanning angle value θ j The corresponding steering vector a(θ j );

[0043] The spatial spectrum estimation unit is used to generate each scanning angle value θ according to the following formula j The corresponding spatial spectrum estimate P MUSIC (θ):

[0044]

[0045] Among them, a H (θ j ) is the steering vector a(θ j ), U H is the transposed matrix of the eigenvalue vector U;

[0046] The interference source angle measurement determination unit is used to select the scanning angle value corresponding to the maximum spatial spectrum estimation value as the interference source angle measurement result.

[0047] The present application uses multi-beam reception and beam amplitude ratio judgment methods to quickly locate the spatial area of ​​the interference source, effectively reducing the time for coverage scanning of the airspace to judge interference, and uses a spatial spectrum estimation method to accurately estimate the angle of the interference source in the determined spatial area of ​​the interference source. This has higher angle measurement accuracy than the conventional single-pulse angle measurement method, and also avoids the high computational load and time-consuming problems of spatial spectrum estimation in the entire airspace range, meeting the requirements of real-time radar processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The present invention is a flowchart of a preferred embodiment of a method for measuring the angle of interference sources in a multi-beam receiving digital array radar.

[0049] Figure 2 For this application Figure 1 DBF multi-beam receive pattern of the illustrated embodiment.

[0050] Figure 3 For this application Figure 1 Multi-beam receive and channel normalized power magnitude plots for the illustrated embodiment.

[0051] Figure 4 For this application Figure 1A schematic diagram of a normalized result of spatial spectrum estimation in the illustrated embodiment. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0053] The first aspect of the present application provides a method for measuring the angle of interference sources for multi-beam reception of a digital array radar, such as Figure 1 As shown, the method mainly includes:

[0054] Step S1, obtaining the wavelength, array element spacing and number of array elements of the radar;

[0055] Step S2, generating steering vectors from a plurality of equally spaced angles respectively, to form equally spaced beams pointed at a plurality of angles;

[0056] Step S3, determining the beam range corresponding to the maximum value of the interference power amplitude of each beam and channel data;

[0057] Step S4: within the beam range, using a spatial spectrum estimation method to calculate the interference source angle.

[0058] In the present application, in steps S1 to S3, the interference space area is determined by multi-beam reception and beam ratio judgment, and then the interference source angle is calculated by the spatial spectrum estimation method in step S4. It should be noted that the digital array radar can adopt the DBF (digital beam forming) multi-beam reception mode through sub-array weighting to form beams covering multiple different angles at the digital signal processing end, thereby reducing the time of searching the airspace, and quickly locating the interference space area by judging the strongest energy ratio of the beam at multiple different angles. The spatial spectrum estimation method is used in the above-mentioned located interference space area to accurately estimate the interference source angle, and a high-precision interference source angle result can be obtained on the basis of reducing the computational load and reducing the time consumption.

[0059] Step S1 is used to obtain radar parameters. For example, taking a uniform azimuth linear array as an example, the number of array elements M is set to 40, the number of array elements is equal to the number of receiving channels, and the array element spacing d is set to half the wavelength λ. Similarly, the method of the present application can also be applied to the pitch dimension.

[0060] Step S2 is used to calculate the steering vector.

[0061] In some optional implementations, in step S2, each angle θ is generated by the following formula: i The corresponding steering vector a(θ i ):

[0062]

[0063] Wherein, e represents the natural logarithm, j represents the imaginary number, κ=2π / λ represents the wave number, π represents the circumference of a circle, λ represents the wavelength, M represents the number of array elements, and d represents the array element spacing.

[0064] In this embodiment, the digital array radar adopts the DBF multi-beam receiving mode, and according to the above formula, the angles θ are equally spaced. i Generate a steering vector a(θ i ), where i = 0, 1, 2, ..., K, thereby forming K equally spaced beams at the digital receiving end. Figure 2 As shown, the angular spacing between adjacent beam centers is twice the half beam width θ 3dB .

[0065] For example, the digital array radar adopts multi-beam receiving mode, assuming the number of angles is 8, θ i Take -11.9, -8.5, -5.1, -1.7, 1.7, 5.1, 8.5, 11.9 respectively, the unit is angle, half beam width θ 3dB is 1.7°, such as Figure 2 As shown, according to the formula, the angles θ are spaced equally i Calculate and generate the corresponding steering vector a(θ i ), and then digitally synthesize the sum of the channel data of each beam and record it as S i [n].

[0066] Step S3 is used to determine the beam range based on the sum channel data.

[0067] In some optional implementations, step S3 further includes:

[0068] Step S31, digitally synthesizing the sum channel data of each beam;

[0069] Step S32, averaging the sum channel data of each beam, and obtaining the interference power amplitude of each beam by statistics;

[0070] Step S33, comparing the interfered power amplitudes of the various beams, and selecting the beam center with the largest interfered power amplitude;

[0071] Step S34: determine the beam range according to the beam center and the preset half beam width.

[0072] In this embodiment, in step S31 and step S32, the interference power amplitude of the "sum channel data" in each beam is counted, and by comparing the amplitudes, in step S33 and step S34, the beam with the largest interference amplitude can be quickly selected, and the beam center is θ p , thus determining that the interference coverage space area is within the main lobe width of the beam, and the interference space area is recorded as [θ p -θ 3dB ,θ p +θ 3dB ],like Figure 3 shown.

[0073] For example, for the steering vector a(θ i ), assuming that the sum channel data of each digitally synthesized beam is denoted as S i [n]. By analyzing the beam and channel data S i [n] is averaged and the amplitude of the interference power of each beam is obtained by statistics, which is recorded as JamPwr i , and then compare the interference amplitudes of each beam, select the main lobe angle range of the beam with the largest interference power amplitude as the interference space angle area, and the normalized interference amplitudes of each beam and channel are as follows: Figure 3 As shown, beam 4 is judged to be the beam with the largest interference amplitude, and its main lobe width [-6.8, -3.4] is the interference space area, in degrees.

[0074] Step S4 is used to calculate the interference source angle using a spatial spectrum estimation method in the selected interference source spatial region.

[0075] In some optional implementations, step S4 further includes:

[0076] Step S41, calculating the covariance matrix of the interference sample points within the beam range;

[0077] Step S42, determining the eigenvalue vector U corresponding to the maximum eigenvalue of the covariance matrix;

[0078] Step S43: Generate multiple scanning angle values ​​according to a preset step length within the beam range, and calculate each scanning angle value θ j The corresponding steering vector a(θ j );

[0079] Step S44: Generate each scanning angle value θ according to the following formula:j The corresponding spatial spectrum estimate P MUSIC (θ):

[0080]

[0081] Among them, a H (θ j ) is the steering vector a(θ j ), U H is the transposed matrix of the eigenvalue vector U;

[0082] Step S45: Select the scanning angle value that maximizes the spatial spectrum estimation value as the interference source angle measurement result.

[0083] This embodiment uses a spatial spectrum estimation method to calculate the interference source angle in the selected interference source spatial region to improve the interference source angle measurement accuracy and avoid the high computing load and time consumption caused by performing spatial spectrum estimation in the entire spatial domain. In step S41, the beam [θ p -θ 3dB ,θ p +θ 3dB The interference sample point information of each channel in ] is recorded as X(t), with a total of L samples, and the interference covariance matrix is ​​calculated:

[0084]

[0085] Afterwards, in step S42, the matrix is ​​eigen-decomposed to obtain the eigenvector U corresponding to the maximum eigenvalue.

[0086] Then, in step S43, the step size of the traversal beam main lobe angle range is selected as Δθ, and the scanning angle is θ=θ p -θ 3dB +m*Δθ, where m=0,1,2,...,N,N=2θ 3dB / Δθ, first generate the corresponding steering vector a(θ).

[0087] Then, in step S44, the spatial spectrum estimation value P is generated according to the formula MUSIC (θ) and record.

[0088] Finally, in step S45, the spatial spectrum estimation value P is selected. MUSIC (θ) The maximum angle value θ is taken as the interference source angle measurement result, and the normalized result of spatial spectrum estimation calculation is as follows: Figure 4 shown.

[0089] For example, the interference source spatial region is [-6.8, -3.4], L is set to 200, and the step Δθ is set to 0.05. The traversal scanning angle value is θ = -6.8 + m*0.05, where m = 0, 1, 2, ..., 68. According to the above formula, it can be calculated that the spatial spectrum estimation value reaches the maximum when θ is -4.6°.

[0090] The interference source angle measurement method provided in the present application can reduce the spatial scanning time and avoid the high computational load and time-consuming disadvantage of full spatial spectrum estimation, and effectively improves the interference source angle measurement accuracy compared with the single pulse angle measurement method.

[0091] The second aspect of the present application provides a digital array radar multi-beam receiving interference source angle measurement device corresponding to the above method, mainly comprising:

[0092] Radar parameter acquisition module, used to obtain the radar wavelength, array element spacing and number of array elements;

[0093] A beam forming module, used to generate steering vectors from multiple equally spaced angles to form equally spaced beams pointed at multiple angles;

[0094] A module for determining a beam range with a maximum interference power amplitude, used to determine a beam range corresponding to a maximum interference power amplitude in each beam and channel data;

[0095] The interference source angle calculation module is used to calculate the interference source angle within the beam range by using a spatial spectrum estimation method.

[0096] In some optional implementations, in the beam forming module, each angle θ is generated by the following formula: i The corresponding steering vector a(θ i ):

[0097]

[0098] Wherein, e represents the natural logarithm, j represents the imaginary number, κ=2π / λ represents the wave number, π represents the circumference of a circle, λ represents the wavelength, M represents the number of array elements, and d represents the array element spacing.

[0099] In some optional implementations, the interference power amplitude maximum beam range determination module includes:

[0100] A sum channel data calculation unit, used for digitally synthesizing the sum channel data of each beam;

[0101] The interference power amplitude statistical unit of each beam is used to average the sum channel data of each beam and obtain the interference power amplitude of each beam by statistics;

[0102] A beam center determination unit with the largest interference power amplitude, used to compare the interference power amplitudes of the various beams and select the beam center with the largest interference power amplitude;

[0103] The beam range determination unit is used to determine the beam range according to the beam center and a preset half beam width.

[0104] In some optional implementations, the interference source angle calculation module includes:

[0105] A covariance matrix calculation unit, used to calculate the covariance matrix of the interference sample points within the beam range;

[0106] An eigenvalue vector determining unit, used to determine an eigenvalue vector U corresponding to the maximum eigenvalue of the covariance matrix;

[0107] A scanning angle value steering vector calculation unit is used to generate multiple scanning angle values ​​according to a preset step size within the beam range, and calculate each scanning angle value θ j The corresponding steering vector a(θ j );

[0108] The spatial spectrum estimation unit is used to generate each scanning angle value θ according to the following formula j The corresponding spatial spectrum estimate P MUSIC (θ):

[0109]

[0110] Among them, a H (θ j ) is the steering vector a(θ j ), U H is the transposed matrix of the eigenvalue vector U;

[0111] The interference source angle measurement determination unit is used to select the scanning angle value corresponding to the maximum spatial spectrum estimation value as the interference source angle measurement result.

[0112] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for measuring the angle of interference source of a digital array radar multi-beam receiver, characterized in that: include: Step S1, obtaining the wavelength, array element spacing and number of array elements of the radar; Step S2, generating steering vectors from a plurality of equally spaced angles respectively, to form equally spaced beams pointed at a plurality of angles; Step S3, determining the beam range corresponding to the maximum value of the interference power amplitude of each beam and channel data; Step S4: within the beam range, using a spatial spectrum estimation method to calculate the interference source angle.

2. The method for measuring the angle of interference source of a digital array radar multi-beam reception as claimed in claim 1, characterized in that: In step S2, each angle θ is generated by the following formula i The corresponding steering vector a(θ i ): Wherein, e represents the natural logarithm, j represents the imaginary number, κ=2π / λ represents the wave number, π represents the circumference of a circle, λ represents the wavelength, M represents the number of array elements, and d represents the array element spacing.

3. The method for measuring the angle of interference source of a digital array radar multi-beam reception as claimed in claim 1, characterized in that: Step S3 further comprises: Step S31, digitally synthesizing the sum channel data of each beam; Step S32, averaging the sum channel data of each beam, and obtaining the interference power amplitude of each beam by statistics; Step S33, comparing the interfered power amplitudes of the various beams, and selecting the beam center with the largest interfered power amplitude; Step S34: determine the beam range according to the beam center and the preset half beam width.

4. The method for measuring the angle of interference source of a digital array radar multi-beam reception as claimed in claim 1, characterized in that: Step S4 further comprises: Step S41, calculating the covariance matrix of the interference sample points within the beam range; Step S42, determining the eigenvalue vector U corresponding to the maximum eigenvalue of the covariance matrix; Step S43: Generate multiple scanning angle values ​​according to a preset step length within the beam range, and calculate each scanning angle value θ j The corresponding steering vector a(θ j ); Step S44: Generate each scanning angle value θ according to the following formula: j The corresponding spatial spectrum estimate P MUSIC (θ): Among them, a H (θ j ) is the steering vector a(θ j ), U H is the transposed matrix of the eigenvalue vector U; Step S45: Select the scanning angle value that maximizes the spatial spectrum estimation value as the interference source angle measurement result.

5. A digital array radar multi-beam receiving interference source angle measurement device, characterized in that: include: Radar parameter acquisition module, used to obtain the radar wavelength, array element spacing and number of array elements; A beam forming module, used to generate steering vectors from multiple equally spaced angles to form equally spaced beams pointed at multiple angles; A module for determining a beam range with a maximum interference power amplitude, used to determine a beam range corresponding to a maximum interference power amplitude in each beam and channel data; The interference source angle calculation module is used to calculate the interference source angle within the beam range by using a spatial spectrum estimation method.

6. The digital array radar multi-beam receiving interference source angle measuring device as claimed in claim 5, characterized in that: In the beamforming module, each angle θ is generated by the following formula: i The corresponding steering vector a(θ i ): Wherein, e represents the natural logarithm, j represents the imaginary number, κ=2π / λ represents the wave number, π represents the circumference of a circle, λ represents the wavelength, M represents the number of array elements, and d represents the array element spacing.

7. The digital array radar multi-beam receiving interference source angle measuring device as claimed in claim 5, characterized in that: The interference power amplitude maximum beam range determination module includes: A sum channel data calculation unit, used for digitally synthesizing the sum channel data of each beam; The interference power amplitude statistical unit of each beam is used to average the sum channel data of each beam and obtain the interference power amplitude of each beam by statistics; A beam center determination unit with the largest interference power amplitude, used to compare the interference power amplitudes of the various beams and select the beam center with the largest interference power amplitude; The beam range determination unit is used to determine the beam range according to the beam center and a preset half beam width.

8. The digital array radar multi-beam receiving interference source angle measuring device as claimed in claim 5, characterized in that: The interference source angle calculation module includes: A covariance matrix calculation unit, used to calculate the covariance matrix of the interference sample points within the beam range; An eigenvalue vector determining unit, used to determine an eigenvalue vector U corresponding to the maximum eigenvalue of the covariance matrix; A scanning angle value steering vector calculation unit is used to generate multiple scanning angle values ​​according to a preset step size within the beam range, and calculate each scanning angle value θ j The corresponding steering vector a(θ j ); The spatial spectrum estimation unit is used to generate each scanning angle value θ according to the following formula j The corresponding spatial spectrum estimate P MUSIC (θ): Among them, a H (θ j ) is the steering vector a(θ j ), U H is the transposed matrix of the eigenvalue vector U; The interference source angle measurement determination unit is used to select the scanning angle value corresponding to the maximum spatial spectrum estimation value as the interference source angle measurement result.

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