A low-resolution scene deception jamming method for three-channel SAR-GMTI

Abstract

The present invention provides a low-resolution scene deception interference method for three-channel SAR-GMTI, which belongs to the field of radar confrontation and artificial intelligence technology. The method includes: using the imaging results of measured data to construct a deception scene template; obtaining a low-resolution deception scene template through low-resolution processing; obtaining interference amplitude gain parameters by constructing functions and optimization methods; combining the interference parameters to perform amplitude modulation, phase modulation and delay modulation on the intercepted radar signal and then forward it to produce realistic false moving target detection results for radar detection. The present invention aims to generate realistic false moving targets by reducing the number of scattering points contained in the template and maintaining a high correlation technology. Compared with the existing deception methods, the signal generated by the present invention matches the target signal in parameters, reduces the number of scattering points contained in the false motion deception template, can greatly reduce the computational complexity, and produce a highly realistic false moving target with an edge contour.

Description

Technical Field

[0001] The present invention relates to the field of radar countermeasure and artificial intelligence technology, and in particular to a low-resolution scene deception jamming method for three-channel SAR-GMTI. Background Art

[0002] With the continuous improvement of synthetic aperture radar resolution, the multi-channel moving target indication technology combined with multi-antenna mechanism has changed the detection results from point targets to surface targets, and can clearly indicate the initial motion position of each scattering point, which has achieved great progress. However, it has posed a huge threat to radar deception and jamming technology. Traditional deception and jamming algorithms still start with two technical approaches: generating false point targets and dense false targets that cannot be canceled to disrupt radar detection.

[0003] In the article "SAR-GMTI Intermittent Sampling Jamming Method Based on Noise Product Modulation" published by Sun Guang et al. in "System Engineering and Electronic Technology", the authors conducted an in-depth study on the use of noise product modulation on intercepted radar signals, which resulted in regional noise in the detection results of the moving target indication stage, thus creating the effect of dense false moving targets. However, this method cannot accurately form false moving targets with specified parameters.

[0004] In the patent "A dual jammer cooperative jamming method for SAR-GMTI system" applied by Xi'an Shengxin Technology Co., Ltd. with the authorization announcement number CN116908792B, a dual-station cooperative jamming method is adopted to avoid the jamming effect being filtered out as a target in the moving target indication stage, producing an uncancellable jamming effect, and thus being mistakenly detected as a moving target by the radar in the moving target indication stage. However, this method also cannot produce realistic and accurate false moving targets.

[0005] In the article "A Smart Multitransmitter Cooperative False Images Generation Method Against Multichannel SAR-GMTI" published by Ji Penghui et al. in "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING", a large number of dense false targets with controllable imaging positions and relocation positions are generated. Although this method reduces the computational complexity, from the experimental results, it is still aimed at low-resolution imaging systems that cannot obtain the edge contours of the target.

[0006] In the article "A Method for Deceiving SAR-GMTI by Using False Motion Scenes Based on Dual-station Amplitude Modulation" published by Chang Xin et al. in the Journal of Electronics and Information Technology, dual interference stations are used to modulate the same false target in the image. By controlling the amplitude of the false target, the phase after interference is controlled, thereby achieving the purpose of controlling the initial motion position after radar detection. However, the false scene template used in this method contains too many scattering points, resulting in high computational complexity. In addition, the interference amplitude parameter of this method is relatively high.

[0007] In short, the traditional jamming method generates point targets, which do not have the characteristics of target contours. In addition, the computational complexity of scene deception jamming is limited by the number of scattering points contained in the template, and the resource requirements are huge. Summary of the invention

[0008] In view of this, the present invention proposes a low-resolution scene deception jamming method for three-channel SAR-GMTI. The present invention adopts a low-resolution processing method to reduce the number of scattering points contained in the false motion deception template, which can greatly reduce the calculation complexity and generate a false motion target with an edge contour.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A low-resolution scene deception jamming method for three-channel SAR-GMTI includes the following steps:

[0011] Step 1: Generate a low-resolution deception scene template;

[0012] Step 2: Calculate the interference amplitude gain of each jammer;

[0013] Step 3: Modulate and forward the intercepted radar signal to form low-resolution scene deception interference.

[0014] Furthermore, the specific method of step 1 is:

[0015] Step 1-1: Use the measured data imaging results to build a deception scene template ; Deception scenario template It is a matrix composed of multiple false scattering points with a dimension of N×M. Each element in the matrix includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth ;

[0016] Step 1-2: Set the cutoff ratio to , using the nearest neighbor interpolation method, the scene deception template Processed as a low-resolution scene template , The dimension is × , = N, = M, Each element in includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth ;

[0017] Step 1-3: Use the cosine similarity function to calculate the scene deception template and low resolution scene templates Similarity ;

[0018] Step 1-4: Update = + , For a fixed step size, repeat steps 1-2 to find a value greater than the similarity threshold. The minimum cutoff ratio ;

[0019] Step 1-5: According to the cut-off ratio , the scene deceives the template Processed as a low-resolution scene template , The dimension is × ,in , ; Each element in includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth ; This is the final generated low-resolution deception scene template.

[0020] Furthermore, the specific method of step 2 is:

[0021] Step 2-1: Based on the low-resolution deception scene template, construct the objective function point by point; the objective function of the false scattering point in the nth row and mth column of the low-resolution deception scene template is:

[0022] ;

[0023] in, , , is the phase operation, * is the conjugate operation, , H is the flight altitude of the radar carrier aircraft, v is the flight speed of the radar carrier aircraft, is the distance between the antennas corresponding to the three processing channels of the radar, λ is the wavelength of the jammer’s interference signal, , is the azimuth position of the lth jammer, is the distance position of the lth jammer, is the set of interference amplitude gains of each jammer corresponding to the false scattering point in the nth row and the mth column, , L is the total number of jammers, is the interference amplitude gain of the lth jammer corresponding to the false scattering point in the nth row and the mth column;

[0024] Step 2-2: Initialize the interference amplitude gain group and iteration speed, where the interference amplitude gain group The K candidate interference amplitude gains constitute, The kth element in , k=1,2,...,K, the alternative interference amplitude gain is initialized with a normal distribution with a mean of 0 and a variance of 1; the iteration speed is determined by the K moving speeds Composition, each moving speed Corresponding to an alternative interference amplitude gain , The dimension is L, It is also initialized using a normal distribution with a mean of 0 and a variance of 1;

[0025] Step 2-3: Substitute each candidate interference amplitude gain into the objective function and calculate the corresponding fitness value; take each candidate interference amplitude gain as the current individual optimal solution , taking the alternative interference amplitude gain with the minimum fitness value as the current group optimal solution ;

[0026] Step 2-4: Update the moving speed of each candidate interference amplitude gain:

[0027]

[0028] in, is the inertia weight, and is the learning factor, and is a random number in the range [0, 1];

[0029] Update the value of each candidate interference amplitude gain:

[0030] ;

[0031] Step 2-5: Traverse all current candidate interference amplitude gains, if , then update ,if , then update ;

[0032] Step 2-6: Repeat steps 2-4 and 2-5 until the optimal solution is found. Make Less than 0.5 times the azimuth main lobe width, the group optimal solution The values ​​in are assigned to the jammers’ jamming amplitude gain corresponding to the nth row and mth column of the low-resolution deception template;

[0033] Step 2-7: Calculate the amplitude correction coefficient of the false scattering point in the nth row and mth column of the corresponding spoof template:

[0034] ;

[0035] Step 2-8: Repeat steps 2-1 to 2-7, traverse the false scattering points in each row and column of the deception template, and obtain the amplitude correction coefficient corresponding to each false scattering point and the interference amplitude gain of each jammer. .

[0036] Furthermore, the specific method of step 3 is:

[0037] Step 3-1: Each jammer receives the radar signal ,in For distance to fast time, is the azimuth slow time;

[0038] Step 3-2: Each jammer performs truncation modulation on the intercepted signal:

[0039] ;

[0040] in, is the radar pulse width and is the radar illumination duration, rect is the rectangular window function;

[0041] Step 3-3: Each jammer performs amplitude modulation, phase modulation and time delay modulation on its intercepted signal point by point according to the false scene template:

[0042] ;

[0043] in:

[0044] ,

[0045] ,

[0046] ,

[0047] ;

[0048] Step 3-4: After modulation is completed, the signal is accumulated:

[0049] ;

[0050] Step 3-5: Each jammer transmits the accumulated jamming signal in the direction of the radar carrier to complete the low-resolution scene deception jamming.

[0051] The beneficial effects of the present invention are:

[0052] 1. Compared with the traditional scene deception interference method, the present invention enhances the information required for the deception interference template and performs low-resolution processing, thereby reducing resource requirements while ensuring the interference effect.

[0053] 2. The present invention proposes an intelligent interference parameter solving method, making the interference parameters easier to solve.

[0054] 3. The present invention can effectively form a false moving target with a controllable initial moving position and an edge contour. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 The figure is a flow chart of a low-resolution scene deception jamming method for three-channel SAR-GMTI.

[0056] Figure 2 Schematic diagram of the deception scenario template.

[0057] Figure 3 Schematic diagram of low-resolution deception scene template.

[0058] Figure 4 This is the real moving target detection result.

[0059] Figure 5 This is a diagram showing the effect of deceiving SAR-GMTI by using a false motion scene based on dual-station amplitude modulation.

[0060] Figure 6 This is a rendering of the effect of a low-resolution scene deception jamming method for three-channel SAR-GMTI. DETAILED DESCRIPTION

[0061] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0062] A low-resolution scene deception jamming method for three-channel SAR-GMTI, such as Figure 1 As shown, the following steps are included:

[0063] Step 1: Low-resolution deception scene template generation.

[0064] Step 1-1: Use the measured data imaging results to construct a deception scene template.

[0065] Deception scenario template It is a matrix composed of multiple false scattering points, with a dimension of N×M, N is 120, M is 40, and each element in the matrix includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth In the embodiment, a truck is used to make a scene template. The schematic diagram of the deception scene template is as follows: Figure 2 In addition, the azimuth velocity and range velocity of each scattering point are both 0.5 m / s.

[0066] Step 1-2: Set the cutoff ratio and process the spoofed scene in low resolution.

[0067] Set the cutoff ratio to , then the processed low-resolution scene template is , dimension N× M, that is × . Use the nearest neighbor interpolation method to deceive the scene template Processed as a low-resolution scene template , each element contains the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth .

[0068] Step 1-3: Use the cosine similarity function to calculate the scene deception template and the low-resolution scene template is Similarity ;

[0069] Step 1-4: Repeat steps 1-2 to =0.1 is the interval, update = + , find a value greater than the similarity threshold The minimum cutoff ratio In this example, the threshold Set to 0.9 to get the minimum cutoff ratio is 0.5;

[0070] Step 1-5: Process to obtain a low-resolution deception scene template.

[0071] According to the cut-off ratio , the scene deceives the template Processed as a low-resolution scene template , the dimension is × ,in and Each element in the matrix includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth The schematic diagram of the deception scenario template is as follows: Figure 3 shown.

[0072] Step 2: Calculate the interference amplitude gain of each jammer.

[0073] Step 2-1: Based on the low-resolution deception scene template, construct the objective function point by point;

[0074] The objective function of the false scattering point in the nth row and mth column of the low-resolution deception scene template is

[0075] ;

[0076] in, , , is the phase operation, * is the conjugate operation, , H is the flight altitude of the radar carrier, which is 5000 m, v is the flight speed of the radar carrier, which is 200 m / s, The distance between the antennas corresponding to the three processing channels of the radar is 1.1088 m. , is the azimuth position of the lth jammer, is the distance position of the lth jammer, is the height of the first jammer. There are three jammers in total. Their azimuth position, range position and height are (10000 m, 0 m, 0 m), (10000 m, 76 m, 0 m) and (10000 m, 151 m, 0 m) respectively. is the set of interference amplitude gains of each jammer corresponding to the false scattering point in the nth row and the mth column, , L is the total number of jammers, which is set to 3.

[0077] Step 2-2: Initialize the interference amplitude gain group and iteration speed.

[0078] Interference Amplitude Gain Group The K candidate interference amplitude gains Composition, K takes 40, , for each amplitude gain Initialize with a normal distribution with a mean of 0 and a variance of 1. Corresponding to a moving speed , dimension and The same is L, and it is initialized using a normal distribution with a mean of 0 and a variance of 1.

[0079] Step 2-3: Initialize the positions of the optimal solutions of each interference amplitude gain and the optimal solution of the interference amplitude gain group.

[0080] Each candidate interference amplitude gain Substitute into the objective function and calculate the corresponding fitness value. Save to individual optimal solution In In addition, the alternative interference amplitude gain with the largest fitness value is stored in the group optimal solution In .

[0081] Step 2-4: Update the moving speed of each candidate interference amplitude gain and the value of the candidate interference amplitude gain.

[0082] Update the moving speed of each candidate interference amplitude gain:

[0083]

[0084] in, is the inertia weight, set to 1, and is the learning factor, set to 2, and is a random number in the range [0, 1].

[0085] Update the value of each candidate interference amplitude gain:

[0086]

[0087] Step 2-5: Update the positions of the optimal solutions of each interference amplitude gain and the optimal solution of the interference amplitude gain group.

[0088] Traverse all candidate interference amplitude gains. If , then update ,Right now .if , then update ,Right now .

[0089] Step 2-6: Repeat steps 2-4 and 2-5 until the optimal solution is found. Make Less than 0.5 times the azimuth main lobe width. The values ​​in are respectively assigned to the interference amplitude gain of each jammer corresponding to the nth row and mth column of the low-resolution deception template.

[0090] Step 2-7: Calculate the amplitude correction coefficient of the false scattering point in the nth row and mth column of the corresponding spoof template:

[0091]

[0092] Step 2-8: Repeat steps 2-1 to 2-7, traverse the false scattering points in each row and column of the deception template, and obtain the amplitude correction coefficient corresponding to each false scattering point and the interference amplitude gain of each jammer. .

[0093] Step 3: Modulate and forward the intercepted radar signal to form low-resolution scene deception interference.

[0094] Step 3-1: Each jammer receives the radar signal ,in For distance to fast time, is the azimuth slow time;

[0095] Step 3-2: Each jammer performs truncation modulation on its own intercepted signal:

[0096]

[0097] in, is the radar pulse width and is the radar illumination duration, and rect is the rectangular window function.

[0098] Step 3-3: Each jammer performs amplitude modulation, phase modulation and time delay modulation on its intercepted signal point by point according to the false scene template;

[0099]

[0100] in:

[0101] ,

[0102]

[0103] ,

[0104] ;

[0105] Step 3-4: After modulation is completed, the signal is accumulated:

[0106] ;

[0107] Step 3-5: Each jammer transmits the accumulated jamming signal in the direction of the radar carrier.

[0108] In order to compare the interference effect, the results of moving targets in radar detection are given, such as Figure 4 shown. Figure 5 This is a diagram showing the effect of the SAR-GMTI deception method using a false motion scene based on dual-station amplitude modulation. Figure 6 The effect diagram of this method is shown in Figure 2. The depth bar next to the figure is used to indicate the initial motion position of the scattering point in the target. By comparison, it can be seen that compared with the false motion scene based on dual-station amplitude modulation to deceive SAR-GMTI, the edge of this method is clearer.

[0109] In order to further objectively evaluate the effect of the method, the correlation coefficient and the mean interference amplitude obtained by comparing with the real moving target are used as evaluation indicators. The correlation coefficient of the false motion scene based on dual-station amplitude modulation for SAR-GMTI deception method is 0.6365, and the mean interference amplitude is 227.7652. The correlation coefficient of this method is 0.9347, and the mean interference amplitude is 1.4502. The implementation results fully demonstrate that this method can produce a highly correlated deception interference effect while reducing the combing of template scattering points, and the required interference amplitude is lower.

[0110] In summary, the present invention aims to generate realistic false moving targets by reducing the number of scattering points contained in the template and maintaining a high correlation technology. Compared with the existing deception methods, the signal generated by the present invention not only matches the target signal in terms of parameters, but also reduces the number of scattering points contained in the false motion deception template, which can greatly reduce the computational complexity and generate a highly realistic false moving target with edge contours.

Claims

1. A low-resolution scene deception jamming method for three-channel SAR-GMTI, characterized in that: The following steps are involved: Step 1: Generate a low-resolution deception scene template; The specific method is: Step 1-1: Use the measured data imaging results to build a deception scene template ; Deception scenario template It is a matrix composed of multiple false scattering points with a dimension of N×M. Each element in the matrix includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth ; Step 1-2: Set the cutoff ratio to , using the nearest neighbor interpolation method, the scene deception template Processed as a low-resolution scene template , The dimension is × , = N, = M, Each element in includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth ; Step 1-3: Use the cosine similarity function to calculate the scene deception template and low resolution scene templates Similarity ; Step 1-4: Update = + , For a fixed step size, repeat steps 1-2 to find a value greater than the similarity threshold. The minimum cutoff ratio ; Step 1-5: According to the cut-off ratio , the scene deceives the template Processed as a low-resolution scene template , The dimension is × ,in , ; Each element in includes the scattering point coefficient , azimuth distance position , distance to distance position , azimuth velocity position , distance to speed position and initial motion position in azimuth ; This is the low-resolution deception scene template that is finally generated; Step 2: Calculate the interference amplitude gain of each jammer; the specific method is: Step 2-1: Based on the low-resolution deception scene template, construct the objective function point by point; the objective function of the false scattering point in the nth row and mth column of the low-resolution deception scene template is: ； in, , , is the phase operation, * is the conjugate operation, , H is the flight altitude of the radar carrier aircraft, v is the flight speed of the radar carrier aircraft, is the distance between the antennas corresponding to the three processing channels of the radar, λ is the wavelength of the jammer’s interference signal, , is the azimuth position of the lth jammer, is the distance position of the lth jammer, is the set of interference amplitude gains of each jammer corresponding to the false scattering point in the nth row and the mth column, , L is the total number of jammers, is the interference amplitude gain of the lth jammer corresponding to the false scattering point in the nth row and the mth column; Step 2-2: Initialize the interference amplitude gain group and iteration speed, where the interference amplitude gain group The K candidate interference amplitude gains constitute, The kth element in , k=1,2,...,K, the alternative interference amplitude gain is initialized with a normal distribution with a mean of 0 and a variance of 1; the iteration speed is determined by the K moving speeds Composition, each moving speed Corresponding to an alternative interference amplitude gain , The dimension is L, It is also initialized using a normal distribution with a mean of 0 and a variance of 1; Step 2-3: Substitute each candidate interference amplitude gain into the objective function and calculate the corresponding fitness value; take each candidate interference amplitude gain as the current individual optimal solution , taking the alternative interference amplitude gain with the minimum fitness value as the current group optimal solution ; Step 2-4: Update the moving speed of each candidate interference amplitude gain: in, is the inertia weight, and is the learning factor, and is a random number in the range [0, 1]; Update the value of each candidate interference amplitude gain: ； Step 2-5: Traverse all current candidate interference amplitude gains, if , then update ,if , then update ; Step 2-6: Repeat steps 2-4 and 2-5 until the optimal solution is found. Make Less than 0.5 times the azimuth main lobe width, the group optimal solution The values ​​in are assigned to the jammers’ jamming amplitude gain corresponding to the nth row and mth column of the low-resolution deception template; Step 2-7: Calculate the amplitude correction coefficient of the false scattering point in the nth row and mth column of the corresponding spoof template: ； Step 2-8: Repeat steps 2-1 to 2-7, traverse the false scattering points in each row and column of the deception template, and obtain the amplitude correction coefficient corresponding to each false scattering point and the interference amplitude gain of each jammer. ; Step 3: Modulate and forward the intercepted radar signal to form low-resolution scene deception interference; the specific method is: Step 3-1: Each jammer receives the radar signal ,in For distance to fast time, is the azimuth slow time; Step 3-2: Each jammer performs truncation modulation on the intercepted signal: ； in, is the radar pulse width and is the radar illumination duration, rect is the rectangular window function; Step 3-3: Each jammer performs amplitude modulation, phase modulation and time delay modulation on its intercepted signal point by point according to the false scene template: ； in: ， ， ， ； Step 3-4: After modulation is completed, the signal is accumulated: ； Step 3-5: Each jammer transmits the accumulated jamming signal in the direction of the radar carrier to complete the low-resolution scene deception jamming.

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