Scene-adaptive synthetic aperture radar deception jamming method and device

Abstract

The application relates to the technical field of radar electronic countermeasure, and provides a scene-adaptive synthetic aperture radar deception jamming method and device. The method matches a target SAR image with each template in a pre-constructed template library, determines a jamming performance index and a concealment index of each template, determines a most suitable jamming template based on the jamming performance index and the concealment index, carries out concealment reinforcement processing on the most suitable jamming template, obtains an optimized jamming template, finally uses the optimized jamming template to modulate a jamming signal to jam a SAR, and the scattering characteristics of a target and a background environment in a SAR image are changed, so that the target and the background environment are integrated, the probability of the target being detected is reduced, and the concealment and robustness of the jamming effect are relatively strong.

Description

Technical Field

[0001] This application relates to the field of radar electronic countermeasures technology, and in particular to a scene-adaptive synthetic aperture radar deception jamming method and apparatus. Background Technology

[0002] Synthetic Aperture Radar (SAR) is an imaging radar that can acquire high-resolution images of ground targets regardless of lighting and weather conditions, making it valuable in fields such as environmental monitoring. To protect sensitive targets from detection, electronic jamming of SAR is necessary.

[0003] SAR electronic jamming methods can be divided into deception jamming methods and suppression jamming methods. Among them, SAR deception jamming transmits jamming signals that simulate the echoes of real ground objects into the SAR system. It can implant false targets in SAR remote sensing images or change the electromagnetic scattering characteristics of real targets. Its characteristics are that the jamming signal has strong coherence with the radar signal and low jamming power. However, the jamming signal modulation computation is large. In addition, the jamming effect of conventional SAR deception jamming methods is highly sensitive to reconnaissance parameters and has poor robustness.

[0004] SAR jamming methods involve transmitting high-power jamming signals into the SAR image, causing targets in the SAR image to be submerged in noise or jamming areas, thus reducing the probability of target detection. Although this method has low dependence on reconnaissance parameters, it has poor concealment and is easily detected and located by jamming equipment.

[0005] Therefore, there is an urgent need for a method to improve the stealth and robustness of SAR electronic jamming. Summary of the Invention

[0006] In view of this, embodiments of this application provide a scene-adaptive synthetic aperture radar deception jamming method and apparatus to solve the problem that existing SAR jamming techniques are difficult to balance the concealment and robustness of jamming effects.

[0007] A first aspect of this application provides a scene-adaptive synthetic aperture radar deception and jamming method, comprising:

[0008] Acquire synthetic aperture radar (SAR) images of the target; the target SAR images include the target to be covered and its background environment;

[0009] The target SAR image is matched with each template in a pre-built template library to determine the interference effectiveness index and concealment index of each template in the template library. The interference effectiveness index is used to characterize the degree of change in the structural features of the target SAR image after the interference corresponding to the template is implanted. The concealment index is used to characterize the power spectral density correlation and amplitude value distribution difference between the target SAR image and the template.

[0010] The most suitable interference template is determined based on the interference effectiveness index and the concealment index.

[0011] The most suitable interference template is enhanced with concealment processing to obtain the optimized interference template;

[0012] The optimized interference template is used to modulate the interference signal to interfere with the SAR.

[0013] A second aspect of this application provides a scene-adaptive synthetic aperture radar deception jamming device, comprising:

[0014] The acquisition module is configured to acquire a synthetic aperture radar (SAR) image of the target; the target SAR image includes the target to be covered and its background environment.

[0015] The matching module is configured to match the target SAR image with each template in a pre-built template library to determine the interference effectiveness index and the concealment index of each template in the template library. The interference effectiveness index is used to characterize the degree of change in the structural features of the target SAR image after the interference corresponding to the template is implanted. The concealment index is used to characterize the power spectral density correlation and amplitude value distribution difference between the target SAR image and the template.

[0016] The filtering module is configured to determine the most suitable interference template based on the interference effectiveness index and the concealment index;

[0017] The optimization module is configured to perform concealment enhancement processing on the best-fit interference template to obtain the optimized interference template;

[0018] The jamming module is configured to modulate the jamming signal using an optimized jamming template and jam the SAR.

[0019] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0020] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0021] The beneficial effects of this application embodiment compared with the prior art are as follows: This application embodiment matches the target SAR image with each template in the pre-built template library, determines the interference effectiveness index and concealment index of each template, determines the most suitable interference template based on the interference effectiveness index and concealment index, and performs concealment enhancement processing on the most suitable interference template to obtain the optimized interference template. Finally, the optimized interference template is used to modulate the interference signal to interfere with the SAR. This achieves the goal of making the target and the background environment blend together by changing the scattering characteristics of the target and the background environment in the SAR image, reducing the probability of the target being detected, and the interference effect has strong concealment and robustness. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic flowchart of a scene-adaptive synthetic aperture radar deception jamming method provided in an embodiment of this application.

[0024] Figure 2 This is a flowchart illustrating the method for determining the interference effectiveness index of each template in the template library provided in this application embodiment.

[0025] Figure 3 This is a flowchart illustrating the method for determining the concealment index of each template in the template library provided in this application embodiment.

[0026] Figure 4 This is a flowchart illustrating the method for obtaining an optimized interference template by performing concealment enhancement processing on the most suitable interference template according to an embodiment of this application.

[0027] Figure 5 This is a schematic diagram of an interference-free SAR image.

[0028] Figure 6 This is a schematic diagram of the result of target detection on an interference-free SAR image.

[0029] Figure 7 This is a schematic diagram of a SAR image after interference using the method provided in the embodiments of this application.

[0030] Figure 8 This is a schematic diagram showing the result of target detection on a SAR image after it has been jammed using the method provided in the embodiments of this application.

[0031] Figure 9 This is a schematic diagram of a scene-adaptive synthetic aperture radar deception jamming device provided in an embodiment of this application.

[0032] Figure 10 This is a schematic diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0033] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0034] The following describes in detail, with reference to the accompanying drawings, a scenario-adaptive synthetic aperture radar deception and jamming method and apparatus according to embodiments of this application.

[0035] As mentioned above, SAR deception jamming, by transmitting jamming signals that simulate the echoes of real ground objects into the SAR system, can implant false targets or alter the electromagnetic scattering characteristics of real targets in SAR remote sensing images. SAR deception jamming typically includes SAR deception jamming methods based on shadow removal and SAR deception jamming methods based on shape alteration.

[0036] Among them, the SAR deception jamming method based on shadow removal increases the amplitude of the target shadow region in the SAR image by transmitting a deception jamming signal into the SAR, thereby eliminating the target shadow and reducing the probability of the target being detected. Although this method has strong concealment, it is extremely sensitive to reconnaissance parameters. Parameter errors can prevent the target shadow from being completely eliminated, resulting in poor robustness.

[0037] Shape-altering-based SAR deception jamming methods alter the scattering characteristics of targets in SAR images by transmitting deception jamming signals, causing targets to be mistakenly identified as other targets or reducing the probability of target detection. However, this method suffers from drawbacks such as extreme sensitivity to reconnaissance parameters and poor robustness.

[0038] In view of this, embodiments of this application provide a method that matches a target SAR image with each template in a pre-built template library, determines the interference effectiveness index and concealment index of each template, determines the most suitable interference template based on the interference effectiveness index and concealment index, performs concealment enhancement processing on the most suitable interference template to obtain an optimized interference template, and finally uses the optimized interference template to modulate the interference signal to interfere with the SAR. This achieves the goal of changing the scattering characteristics of the target and the background environment in the SAR image, making the target blend into the background environment, reducing the probability of the target being detected, and the interference effect has strong concealment and robustness.

[0039] Figure 1 This is a schematic flowchart illustrating a scene-adaptive synthetic aperture radar deception and jamming method provided in an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0040] In step S101, the target SAR image is acquired.

[0041] The target SAR image includes the target to be covered and its background environment.

[0042] In step S102, the target SAR image is matched with each template in the pre-built template library to determine the interference effectiveness index and concealment index of each template in the template library.

[0043] Among them, the interference effectiveness index is used to characterize the degree of change in the structural features of the target SAR image after the interference corresponding to the template is implanted; the concealment index is used to characterize the power spectral density correlation and amplitude value distribution difference between the target SAR image and the template.

[0044] In step S103, the most suitable interference template is determined based on the interference effectiveness index and the concealment index.

[0045] In step S104, the best-fit interference template is subjected to concealment enhancement processing to obtain the optimized interference template.

[0046] In step S105, the optimized interference template is used to modulate the interference signal to interfere with the SAR.

[0047] In some embodiments of this application, the method may be executed by a jammer or by other terminal devices that are communicatively connected to the jammer, and no limitation is made here.

[0048] In some embodiments of this application, a target SAR image may be acquired first. This target SAR image may include the target to be covered and its background environment.

[0049] In some embodiments of this application, the target SAR image can be matched with each template in a pre-built template library to determine the interference effectiveness index and concealment index of each template in the template library, and the most suitable interference template can be determined based on the interference effectiveness index and concealment index.

[0050] The template library can be pre-built in the following way: extract image slices of various typical land features (such as buildings, trees, hills, etc.) from existing SAR images and build a template library composed of these image slices.

[0051] The interference effectiveness index characterizes the degree to which the structural features of a target SAR image change after interference corresponding to the template is implanted. The more features of the target image are changed, the lower the probability of the target being detected, indicating a better interference effect.

[0052] The stealth index is used to characterize the correlation of power spectral density and the difference in amplitude distribution between the target SAR image and the template. The higher the correlation of power spectral density and the smaller the difference in amplitude distribution, the better the template matches the background environment of the SAR image, the less likely the interference is to be detected, and the better the stealth.

[0053] In some embodiments of this application, the optimal jamming template can be further enhanced with concealment to obtain an optimized jamming template. Finally, the optimized jamming template is used to modulate the jamming signal to interfere with the SAR.

[0054] According to the technical solution provided in the embodiments of this application, the target SAR image is matched with each template in a pre-built template library to determine the interference effectiveness index and concealment index of each template. Based on the interference effectiveness index and concealment index, the most suitable interference template is determined, and the most suitable interference template is subjected to concealment enhancement processing to obtain an optimized interference template. Finally, the optimized interference template is used to modulate the interference signal to interfere with the SAR. This achieves the goal of making the target and the background environment blend together by changing the scattering characteristics of the target and the background environment in the SAR image, thereby reducing the probability of the target being detected. Moreover, the interference effect has strong concealment and robustness.

[0055] Figure 2 This is a flowchart illustrating the method for determining the interference effectiveness index of each template in the template library provided in this application embodiment. For example... Figure 2 As shown, the method includes the following steps:

[0056] In step S201, a two-dimensional coordinate system is established in the reference image, using the target SAR image as the reference image.

[0057] In this system, the origin of the two-dimensional coordinate system is the center point of the target to be protected, and the horizontal axis is... The direction is the SAR ground distance, and the vertical axis is [missing information]. The direction is the SAR azimuth.

[0058] In step S202, the implantation position deviation model of the interference template is input.

[0059] The implantation position deviation model includes at least the ground distance deviation, azimuth deviation, and probability density functions of the ground distance deviation and azimuth deviation relative to the center position of the interference template implantation to the preset position.

[0060] In step S203, the expected interference image amplitude of the template to be implanted is determined based on the implantation position deviation model of the interference template, thereby determining the expected interference image of the template to be implanted.

[0061] The template to be implanted is the kth template in the pre-built template library, where k is a positive integer greater than 0 and less than or equal to n, and n is the total number of templates in the pre-built template library.

[0062] In step S204, the structural similarity between the reference image and the expected interference image is determined at least based on the amplitude of the expected interference image.

[0063] In step S205, the interference effectiveness index is determined at least based on structural similarity.

[0064] In some embodiments of this application, when determining the jamming effectiveness index of each template, a two-dimensional coordinate system can be established first, using the target SAR image as a reference image. The origin of this two-dimensional coordinate system can be the center point of the target to be covered, and the horizontal axis... The direction is the SAR ground distance, and the vertical axis is [missing information]. The direction is the SAR azimuth. Reference image is in... The amplitude value at that point can be expressed as The k-th template is The amplitude value at that point can be expressed as .

[0065] In some embodiments of this application, an implantation position deviation model of the interference template can be input. The implantation position deviation model includes at least the ground distance deviation, azimuth deviation, and probability density functions of the ground distance deviation and azimuth deviation relative to the implantation center position of the interference template and a preset position.

[0066] The implantation center of the jamming template is random; the exact point cannot be determined before jamming is complete, but the probability at each point is known and described by a probability density function. The preset implantation center can be the center of the target to be covered; ideally, the template can be directly implanted at the target's location. In one example, the ground distance deviation of the jamming template implantation center relative to the preset position can be denoted as... The azimuth deviation is denoted as The probability density functions of the distance deviation and azimuth deviation are denoted as follows: .

[0067] In some embodiments of this application, the expected interference image amplitude of the template to be implanted can be determined based on an implantation position deviation model of the interference template, thereby determining the expected interference image of the template to be implanted. Next, the structural similarity between the reference image and the expected interference image can be determined at least based on the expected interference image amplitude. Finally, the interference effectiveness index is determined at least based on this structural similarity.

[0068] In some implementations, formulas can be used. Calculate the expected interference image amplitude of the template to be implanted; where, When the positional deviation of the template implantation is equal to The amplitude value of the expected interference image at that time. For the template to be implanted at the point The amplitude value at that point.

[0069] Formulas can also be used Calculate the structural similarity between the reference image and the expected interference image; where, The structural similarity between the reference image and the expected interference image, for The mean, for exist and The mean of the dimension, for variance for exist and Variance of dimension for and exist and Covariance of dimension and All are constants.

[0070] In some embodiments of this application, formulas can be used. Calculate the interference effectiveness index of each template; where, The interference effectiveness index is the template to be implanted, i.e., the kth template in the template library.

[0071] Figure 3 This is a flowchart illustrating the method for determining the concealment index of each template in the template library provided in this application embodiment. For example... Figure 3 As shown, the method includes the following steps:

[0072] In step S301, the target SAR image is subjected to threshold segmentation processing using a first preset segmentation threshold, and the template to be implanted is subjected to threshold segmentation and weighting processing to obtain the processed target SAR image and the processed template image to be implanted.

[0073] In step S302, the Pearson correlation coefficient of the power spectral density of the processed target SAR image and the processed template image to be implanted is determined.

[0074] In step S303, the target SAR image is divided into N regions centered on the target to be covered.

[0075] One circular region and N-1 annular regions do not intersect; N is a positive integer;

[0076] In step S304, the weighted amplitude histogram of the target SAR image is determined based on the amplitude histograms of the target SAR image in N regions.

[0077] In step S305, the KL divergence between the target SAR image and the template image to be implanted is determined based at least on the weighted amplitude histogram of the target SAR image and the amplitude histogram of the template image to be implanted.

[0078] In step S306, the concealment index is determined based on the Pearson correlation coefficient and the KL divergence.

[0079] In some embodiments of this application, when determining the concealment index of each template, the target SAR image can first be thresholded using a first preset segmentation threshold, and then the template to be implanted can be thresholded and weighted to obtain the processed target SAR image and the processed template image to be implanted. Thresholding refers to setting the portion of the image below a threshold to zero.

[0080] In one example, a formula can be used. SAR images of targets Threshold segmentation is performed to obtain the processed target SAR image. and use the formula Treatment of implantation template Threshold segmentation is performed to obtain the processed template to be implanted. .in, For weighted functions, The first preset segmentation threshold is set according to actual needs, and there is no restriction here.

[0081] In some embodiments of this application, formulas can be used. Calculate the Pearson correlation coefficient of the power spectral density of the processed target SAR image and the processed template image to be implanted; where, The Pearson correlation coefficient is used. The power spectral density of the processed target SAR image. The power spectral density of the processed template image to be implanted. and They are direction and Angular frequency of direction, This indicates the calculation of the Pearson correlation coefficient between two random variables.

[0082] , For the processed target SAR image, the function and They represent direction and Fast Fourier Transform of Direction, Sign This indicates the range of a complex number.

[0083] , This is the processed template image to be implanted.

[0084] In some embodiments of this application, the target SAR image can be divided into N regions centered on the target to be covered, wherein one circular region and N-1 annular regions do not intersect; N is a positive integer. That is, the target SAR image can be divided into N regions centered on the target to be covered, the N regions include one circular region and N-1 annular regions, and any two regions among the N regions do not intersect.

[0085] Taking N=3 as an example, we can visualize it. The area is divided into three zones centered on the target: Zone 1 is a circular zone with a diameter of 30 meters centered on the target; Zone 2 is an annular zone with an inner diameter of 30 meters and an outer diameter of 60 meters centered on the target; and Zone 3 is an annular zone with an inner diameter of 60 meters and an outer diameter of 90 meters centered on the target. It is understood that the diameter of the circular zone and the inner and outer diameters of each annular zone can be adjusted according to actual conditions; no restrictions are imposed here.

[0086] In some embodiments of this application, the weighted amplitude histogram of the target SAR image can be determined based on the amplitude histogram of the target SAR image in N regions, and the KL divergence (KL Divergence, KLD) between the target SAR image and the template image to be implanted can be determined at least based on the weighted amplitude histogram of the target SAR image and the amplitude histogram of the template image to be implanted.

[0087] Taking N=3 as an example, if the amplitude histograms of the target SAR image in region 1, region 2, and region 3 are respectively denoted as... , and ,in If we consider all possible discretized magnitude values ​​of the target SAR image, then we can use the formula... Calculate target SAR image Weighted magnitude histogram Where i is the discrete index of all possible discretized magnitude values ​​of the image, i is greater than or equal to 1 and less than or equal to N.

[0088] In some embodiments of this application, formulas can be used. Calculate the KL divergence between the target SAR image and the template to be implanted; where Let KL divergence be the KL divergence. The amplitude histogram of the template to be implanted, with symbols... To express summation, the function... Represents a logarithmic function.

[0089] Furthermore, formulas can be used to calculate. The KL divergence of the template to be implanted, where, The concealment index is the function. This represents an exponential function.

[0090] In some embodiments of this application, determining the most suitable interference template based on the interference effectiveness index and the concealment index can be achieved using the formula... The template number that best matches the jamming template is determined based on the jamming effectiveness index and the concealment index. ;in, For interference effectiveness index, As a concealment index, For interference performance weights, For hidden weights, the function It is the inverse function of the maximum value function, used to find the maximum value of a function. Value. Using this method, the most suitable interference template can be determined.

[0091] For example: Assume the target to be covered is a vehicle, and the background is a jungle. Template 1 is a square building, Template 2 is trees, and Template 3 is a mound. Interference effectiveness index: Template 1 > Template 2 > Template 3 (implanting a building has the greatest impact on the vehicle's characteristics); Concealment index: Template 2 > Template 3 > Template 1 (trees best match the jungle background and are least noticeable). Finally, considering both indices, Template 2 is selected as the most suitable interference template.

[0092] Figure 4 This is a flowchart illustrating the method for obtaining an optimized interference template by performing concealment enhancement processing on the most suitable interference template, as provided in an embodiment of this application. Figure 4As shown, the method includes the following steps:

[0093] In step S401, the most suitable interference template is segmented using a second preset segmentation threshold to obtain the segmented image.

[0094] In step S402, the segmented image is multiplied by a preset weight function to obtain the optimized interference template.

[0095] The preset weight function has a value of 1 in the middle region and decreases from 1 to 0 in the edge region. The middle region is a circular region with the center of the segmented image as the center and the preset value as the radius, and the edge region is the region outside the middle region.

[0096] In some embodiments of this application, the optimized interference template can be obtained by performing concealment enhancement processing on the best-fit interference template. This can be achieved by first applying a second preset segmentation threshold to the best-fit interference template. Thresholding segmentation is performed to obtain the segmented image. .

[0097] Then the segmented image Multiply by a preset weight function The optimized interference template is obtained. .

[0098] In some embodiments of this application, an optimized jamming template can be used to modulate jamming signals and interfere with SAR, thereby achieving template implantation and target cover.

[0099] There are many methods for modulating interference signals based on interference templates and embedding corresponding interference templates at preset locations, such as SAR convolutional modulation deception interference and SAR time-frequency cross-product deception interference. The general process of these methods includes: intercepting the SAR signal, modulating the intercepted SAR signal according to the interference template, and transmitting interference signals to the SAR. The technical details of these methods can be obtained from relevant literature; therefore, the specific implementation process of this part is not within the scope of this application.

[0100] The technical solution provided in this application can adaptively select interference templates that are compatible with the environment based on the target and its background environment. After interference, the target and the background environment are blended together and are not easily detected. The interference effect has strong concealment and is not sensitive to errors, and has strong robustness.

[0101] This application provides examples of SAR images obtained by performing computer simulation jamming experiments on airborne SAR using the method provided in this application. For ease of comparison, this application also provides SAR images of the same area before jamming.

[0102] Figure 5This is a SAR image of the target area under interference-free conditions provided in the embodiments of this application. For example... Figure 5 As shown, before the interference, the three vehicle targets in the SAR image were clearly visible, with two vehicles on the grass and one vehicle within a building area. Target detection was performed on the SAR image before interference using a trained YOLO-v5 neural network model, and the detection results are shown below. Figure 6 As shown, the white solid-lined boxes represent the detected targets. From Figure 6 As can be seen, all three vehicle targets were detected.

[0103] Then, computer simulation interference was performed using the method provided in the embodiments of this application. Random deviations in the interference implantation location were incorporated into the simulation to verify the robustness of the method. The interfered SAR image is shown below. Figure 7 As shown. From Figure 7 As can be seen, the two vehicles on the grass were implanted with interference templates similar to the surrounding trees, while the vehicle located within the building area was implanted with interference templates similar to the surrounding buildings. The interfered vehicle targets blended into the background environment and were difficult to identify, indicating that the method provided in this application embodiment can adaptively generate interference templates according to the target and its background environment and achieve a concealed interference effect.

[0104] Target detection was performed on the jammed SAR image, and the detection results are as follows: Figure 8 As shown, the white dashed boxes represent undetected targets. From Figure 8 As can be seen, none of the three vehicle targets were detected, indicating that the method provided in this application embodiment can effectively reduce the probability of the targets being detected, achieve the purpose of covering the targets, and the method has strong robustness.

[0105] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0106] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0107] Figure 9 This is a schematic diagram of a scene-adaptive synthetic aperture radar deception jamming device provided in an embodiment of this application. Figure 9 As shown, the device includes:

[0108] The acquisition module 901 is configured to acquire a synthetic aperture radar (SAR) image of the target; the target SAR image includes the target to be covered and the background environment of the target to be covered.

[0109] The matching module 902 is configured to match the target SAR image with each template in a pre-built template library to determine the interference effectiveness index and the concealment index of each template in the template library. The interference effectiveness index is used to characterize the degree of change in the structural features of the target SAR image after the interference corresponding to the template is implanted. The concealment index is used to characterize the power spectral density correlation and amplitude value distribution difference between the target SAR image and the template.

[0110] The filtering module 903 is configured to determine the most suitable interference template based on the interference effectiveness index and the concealment index.

[0111] Optimization module 904 is configured to perform concealment enhancement processing on the best-fit interference template to obtain the optimized interference template.

[0112] The jamming module 905 is configured to modulate the jamming signal using an optimized jamming template and jam the SAR.

[0113] According to the technical solution provided in the embodiments of this application, the target SAR image is matched with each template in a pre-built template library to determine the interference effectiveness index and concealment index of each template. Based on the interference effectiveness index and concealment index, the most suitable interference template is determined, and the most suitable interference template is subjected to concealment enhancement processing to obtain an optimized interference template. Finally, the optimized interference template is used to modulate the interference signal to interfere with the SAR. This achieves the goal of making the target and the background environment blend together by changing the scattering characteristics of the target and the background environment in the SAR image, thereby reducing the probability of the target being detected. Moreover, the interference effect has strong concealment and robustness.

[0114] In some implementations, determining the interference effectiveness index of each template in the template library includes: establishing a two-dimensional coordinate system in the reference image, using the target SAR image as a reference image; wherein the origin of the two-dimensional coordinate system is the center point of the target to be covered, and the horizontal axis is... The direction is the SAR ground distance, and the vertical axis is [missing information]. The direction is the SAR azimuth direction; the input is the implantation position deviation model of the interference template; wherein, the implantation position deviation model includes at least the distance deviation, azimuth deviation and probability density functions of the distance deviation and azimuth deviation of the implantation center position of the interference template relative to the preset position; the expected interference image amplitude of the template to be implanted is determined based on the implantation position deviation model of the interference template, and then the expected interference image of the template to be implanted is determined; the template to be implanted is the k-th template in the pre-built template library, where k is a positive integer greater than 0 and less than or equal to n, and n is the total number of templates in the pre-built template library; the structural similarity between the reference image and the expected interference image is determined at least based on the expected interference image amplitude; the interference effectiveness index is determined at least based on the structural similarity.

[0115] In some implementations, the structural similarity between the reference image and the expected interference image is determined by a formula. Determined; among them, For structural similarity, This is the deviation in distance from the ground. This is the azimuth deviation. for The mean, For reference image at point The amplitude value at that point, for exist and The mean of the dimension, When the positional deviation of the template implantation is equal to The amplitude value of the expected interference image at that time, and , For the template to be implanted at the point The amplitude value at that point; for variance for exist and Variance of dimension for and exist and Covariance of dimension and All are constants.

[0116] In some implementations, the interference effectiveness index is expressed by a formula. Determined; among them, For interference effectiveness index, Let be the probability density functions of the distance deviation and the azimuth deviation.

[0117] In some implementations, determining the concealment index of each template in the template library includes: performing threshold segmentation on the target SAR image using a first preset segmentation threshold, and performing threshold segmentation and weighting on the template to be implanted to obtain the processed target SAR image and the processed template image to be implanted; determining the Pearson correlation coefficient of the power spectral density of the processed target SAR image and the processed template image to be implanted; dividing the target SAR image into N regions centered on the target to be covered; wherein one circular region and N-1 annular regions do not intersect; N is a positive integer; determining the weighted amplitude histogram of the target SAR image based on the amplitude histogram of the target SAR image in the N regions; determining the KL divergence between the target SAR image and the template image to be implanted based at least on the weighted amplitude histogram of the target SAR image and the amplitude histogram of the template image to be implanted; and determining the concealment index based on the Pearson correlation coefficient and the KL divergence.

[0118] In some implementations, the Pearson correlation coefficient is expressed by the formula... Determined; among them, The Pearson correlation coefficient is used. The power spectral density of the processed target SAR image. The power spectral density of the processed template image to be implanted. and They are direction and Angular frequency of direction, This indicates the calculation of the Pearson correlation coefficient between two random variables; , For the processed target SAR image, the function and They represent direction and Fast Fourier Transform of Direction, Sign Indicates the amplitude value of a complex number; , This is the processed template image to be implanted.

[0119] In some implementations, the KL divergence is expressed by the formula Determined; among them, Let KL divergence be the KL divergence. For the weighted magnitude histogram, For all possible discretized magnitude values ​​of the image, Discretize the numbering of all possible discretized magnitude values ​​of the image. The amplitude histogram of the template image to be implanted, with symbols... To express summation, the function... Represents a logarithmic function; the concealment index is expressed by the formula. Determined; among them, The concealment index is the function. This represents an exponential function.

[0120] In some implementations, the optimal jamming template is determined based on the jamming effectiveness index and the concealment index, including: using the formula The template number that best matches the jamming template is determined based on the jamming effectiveness index and the concealment index. ;in, For interference effectiveness index, As a concealment index, For interference performance weights, For hidden weights, the function It is the inverse function of the maximum value function, used to find the maximum value of a function. value.

[0121] In some implementations, the optimal interference template is obtained by performing a concealment enhancement process on the best-fit interference template, including: performing threshold segmentation on the best-fit interference template with a second preset segmentation threshold to obtain a segmented image; and multiplying the segmented image by a preset weight function to obtain the optimized interference template.

[0122] The preset weight function takes a value of 1 in the middle region and decreases from 1 to 0 in the edge region. The middle region is a circular region with the center of the segmented image as the center and the preset value as the radius, while the edge region is the region outside the middle region.

[0123] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0124] Figure 10 This is a schematic diagram of the electronic device provided in an embodiment of this application. For example... Figure 10 As shown, the electronic device 10 of this embodiment includes: a processor 1001, a memory 1002, and a computer program 1003 stored in the memory 1002 and executable on the processor 1001. When the processor 1001 executes the computer program 1003, it implements the steps in the various method embodiments described above. Alternatively, when the processor 1001 executes the computer program 1003, it implements the functions of each module / unit in the various device embodiments described above.

[0125] Electronic device 10 may be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 10 may include, but is not limited to, a processor 1001 and a memory 1002. Those skilled in the art will understand that... Figure 10 This is merely an example of electronic device 10 and does not constitute a limitation on electronic device 10. It may include more or fewer components than shown, or different components.

[0126] The processor 1001 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0127] The memory 1002 can be an internal storage unit of the electronic device 10, such as a hard disk or RAM of the electronic device 10. The memory 1002 can also be an external storage device of the electronic device 10, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, FlashCard, etc., equipped on the electronic device 10. The memory 1002 can also include both internal and external storage units of the electronic device 10. The memory 1002 is used to store computer programs and other programs and data required by the electronic device.

[0128] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0129] If an integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium may include: any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0130] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A scene-adaptive synthetic aperture radar deception and jamming method, characterized in that, include: Acquire a synthetic aperture radar (SAR) image of the target; the target SAR image includes the target to be covered and the background environment of the target to be covered; The target SAR image is matched with each template in a pre-built template library to determine the interference effectiveness index and concealment index of each template. The interference effectiveness index characterizes the degree of change in the structural features of the target SAR image after the interference corresponding to the template is implanted; the greater the change in the structural features of the target SAR image, the larger the interference effectiveness index. The concealment index characterizes the power spectral density correlation and amplitude distribution difference between the target SAR image and the template; the higher the power spectral density correlation or the smaller the amplitude distribution difference, the larger the concealment index. The most suitable interference template is determined based on the interference effectiveness index and the concealment index. The most suitable interference template is subjected to a concealment enhancement process to obtain an optimized interference template; The optimized interference template is used to modulate the interference signal to interfere with the SAR.

2. The method according to claim 1, characterized in that, Determine the interference effectiveness index for each template in the template library, including: Using the target SAR image as a reference image, a two-dimensional coordinate system is established in the reference image; wherein the origin of the two-dimensional coordinate system is the center point of the target to be covered, and the horizontal coordinate is... The direction is the SAR ground distance, and the vertical axis is [missing information]. The direction is the SAR azimuth. Input the implantation position deviation model of the interference template; wherein, the implantation position deviation model includes at least the ground distance deviation, azimuth deviation and probability density functions of the ground distance deviation and azimuth deviation of the implantation center position of the interference template relative to the preset position; The expected interference image amplitude of the template to be implanted is determined based on the implantation position deviation model of the interference template, and then the expected interference image of the template to be implanted is determined; the template to be implanted is the kth template in the pre-built template library, where k is a positive integer greater than 0 and less than or equal to n, and n is the total number of templates in the pre-built template library. The structural similarity between the reference image and the expected interference image is determined at least based on the magnitude of the expected interference image. The interference effectiveness index is determined at least based on the structural similarity.

3. The method according to claim 2, characterized in that, The structural similarity between the reference image and the expected interference image is determined by the formula. Sure; in, The structural similarity is... The distance deviation is the distance from the ground. The azimuth deviation is mentioned above. for The mean, For reference image at point The amplitude value at that point, for exist and The mean of the dimension, When the positional deviation of the template implantation is equal to The amplitude value of the expected interference image at that time, and , For the template to be implanted at point The amplitude value at that point; for variance for exist and Variance of dimension for and exist and Covariance of dimension and All are constants.

4. The method according to claim 3, characterized in that, The interference effectiveness index is expressed by the formula... Sure; in, The interference effectiveness index is... Let be the probability density function of the distance deviation and azimuth deviation.

5. The method according to claim 2, characterized in that, Determine the concealment index of each template in the template library, including: The target SAR image is subjected to threshold segmentation processing using a first preset segmentation threshold, and the template to be implanted is subjected to threshold segmentation and weighting processing to obtain the processed target SAR image and the processed template image to be implanted. Determine the Pearson correlation coefficient of the power spectral density of the processed target SAR image and the processed template image to be implanted; The target SAR image is divided into N regions centered on the target to be covered; one circular region and N-1 annular regions do not intersect; N is a positive integer; The weighted amplitude histogram of the target SAR image is determined based on the amplitude histograms of the target SAR image in the N regions; The KL divergence between the target SAR image and the template image to be implanted is determined based at least on the weighted amplitude histogram of the target SAR image and the amplitude histogram of the template image to be implanted; The concealment index is determined based on the Pearson correlation coefficient and the KL divergence.

6. The method according to claim 5, characterized in that, The Pearson correlation coefficient is obtained through the formula... Sure; in, The Pearson correlation coefficient is... The power spectral density of the processed target SAR image. The power spectral density of the processed template image to be implanted. and They are direction and Angular frequency of direction, This indicates the calculation of the Pearson correlation coefficient between two random variables; , For the processed target SAR image, the function and They represent direction and Fast Fourier Transform of Direction, Sign Indicates the amplitude value of a complex number; , The processed template image to be implanted.

7. The method according to claim 6, characterized in that, The KL divergence is expressed by the formula... Determined; among them, Let KL divergence be the KL divergence. For the weighted magnitude histogram, For all possible discretized magnitude values ​​of the image, Discretize the numbering of all possible discretized magnitude values ​​of the image. The amplitude histogram of the template image to be implanted, with the symbol... To express summation, the function Represents a logarithmic function; The concealment index is calculated using the formula... Determined; among them, Let the concealment index be the function. This represents an exponential function.

8. The method according to claim 1, characterized in that, The optimal interference template is determined based on the interference effectiveness index and the concealment index, including: Use formula Based on the interference effectiveness index and the concealment index, the template number of the most suitable interference template is determined. ;in, The interference effectiveness index is... The concealment index is... For interference performance weights, For hidden weights, the function It is the inverse function of the maximum value function, used to find the maximum value of a function. value.

9. The method according to claim 1, characterized in that, The optimized interference template is obtained by performing a concealment enhancement process on the best-fit interference template, including: The most suitable interference template is subjected to threshold segmentation using a second preset segmentation threshold to obtain the segmented image; The segmented image is multiplied by a preset weight function to obtain the optimized interference template; The preset weight function has a value of 1 in the middle region and a value decreasing from 1 to 0 in the edge region. The middle region is a circular region with the center of the segmented image as the center and a preset value as the radius. The edge region is the region outside the middle region.

10. A scene-adaptive synthetic aperture radar deception jamming device, characterized in that, include: The acquisition module is configured to acquire synthetic aperture radar (SAR) images of the target. The target SAR image includes the target to be covered and the background environment of the target; The matching module is configured to match the target SAR image with each template in a pre-built template library to determine the interference effectiveness index and the concealment index of each template in the template library. The interference effectiveness index characterizes the degree of change in the structural features of the target SAR image after the insertion of interference corresponding to the template; the greater the change in the structural features of the target SAR image, the larger the interference effectiveness index. The concealment index characterizes the power spectral density correlation and amplitude distribution difference between the target SAR image and the template; the higher the power spectral density correlation or the smaller the amplitude distribution difference, the larger the concealment index. The filtering module is configured to determine the most suitable interference template based on the interference effectiveness index and the concealment index; The optimization module is configured to perform a concealment enhancement process on the best-fit interference template to obtain an optimized interference template. The jamming module is configured to modulate the jamming signal using the optimized jamming template and jam the SAR.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 9.

12. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 9.

Images