A high-resolution SAR deception jamming signal fast generation method and device

Abstract

The application discloses a high-resolution SAR deception jamming signal fast generation method and device, and belongs to the technical field of radar countermeasure. The method comprises the following steps: intercepting a SAR signal and measuring parameters of the SAR signal; acquiring a deception jamming template image, and performing edge optimization processing; two-dimensionally dividing the template in a range direction and an azimuth direction to obtain a plurality of sub-templates; calculating a phase compensation function for a center point of each sub-template, and performing phase optimization; superimposing the optimized sub-templates to generate a high-quality product modulation matrix; multiplying the matrix with the intercepted SAR signal, performing digital-to-analog conversion and frequency up-conversion, and then transmitting to form a deception jamming signal. Through the block phase compensation and the template edge optimization, the application significantly improves the imaging quality and concealment of the deception jamming image under the high-resolution SAR, meanwhile, a relatively low calculation complexity is maintained, and the application is suitable for a spaceborne and airborne SAR system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of radar countermeasures, and particularly relates to a high-resolution SAR deception jamming signal rapid generation method and device. BACKGROUND

[0002] Synthetic Aperture Radar (SAR) is widely used in military reconnaissance and civil remote sensing fields due to its all-weather and high-resolution imaging capabilities. With the progress of SAR imaging technology, the exposure risk of high-value targets has significantly increased, and electronic jamming technology against SAR has become a research focus. Active jamming is mainly divided into suppression jamming and deception jamming. Suppression jamming covers the target area by transmitting high-power noise, which is simple to implement but has high power consumption and is easy to expose. Deception jamming generates false targets by modulating and forwarding SAR signals, which has low power consumption, strong concealment, and more practical advantages.

[0003] In existing deception jamming methods, product modulation jamming is widely used due to its high calculation efficiency and good real-time performance. This method constructs a frequency shift modulation matrix to implant false point targets in the imaging results and form a deception scene. However, the traditional method has a significant defocusing problem when generating large scene jamming: point targets far from the jamming center will cause imaging quality degradation due to residual range migration and azimuth frequency mismatch, especially in high-resolution SAR systems. For example, some scholars (Chinese patent publication number: CN120294687A) use product modulation to achieve multi-mode jamming, but do not solve the defocusing problem caused by two-dimensional frequency shift; other scholars (Chinese patent publication number: CN119395645A) generate false points by real-time calculation of slant range difference, which has high imaging quality, but the calculation amount increases sharply with the number of targets, making it difficult to meet the real-time jamming demand of large scenes. In addition, some scholars (Chinese patent publication number: CN119959890B) perform phase compensation on the backscattering coefficient of each false point target, which can effectively deceive small targets with fewer scattering points. However, when the deception jamming scene is large, phase compensation on each point will greatly increase the computational complexity, making it difficult to meet the real-time calculation demand of large scenes.

[0004] Therefore, how to effectively improve the imaging quality and edge naturalness of large scene and high-resolution SAR deception jamming while maintaining low computational complexity has become a technical problem that needs to be solved urgently. SUMMARY

[0005] To solve the above technical problems, the application provides a high-resolution SAR deception jamming signal fast generation method and device, improves the traditional product modulation deception jamming method, and realizes high-quality deception jamming images in both spaceborne and airborne high-resolution synthetic aperture radar (SAR) systems; the size of a suitable sub-template is analyzed to ensure that the required imaging quality requirements are met; a template image edge optimization scheme is proposed to solve the discontinuity problem between the edge of the jamming area and the real background in the deception jamming process; and the method has wider applicability and higher deception performance.

[0006] To achieve the above object, the technical scheme adopted by the application is as follows:

[0007] A high-resolution SAR deception jamming signal fast generation method, the method comprising:

[0008] Step one, the jammer intercepts the signal transmitted from the SAR platform, measures the signal parameters, and calculates the product modulation matrix for generating deception jamming;

[0009] Step two, a deception jamming template image to be generated is obtained, and a Gaussian weighting window function is applied to the template image to perform edge optimization processing according to requirements;

[0010] Step three, the optimized template image is subjected to two-dimensional block processing to obtain a plurality of non-overlapping sub-templates;

[0011] Step four, a compensation coefficient is derived, the center position of each sub-template is subjected to phase compensation, all the sub-templates subjected to phase compensation are added, and a product modulation jamming matrix with optimized imaging quality is obtained;

[0012] Step five, the product modulation jamming matrix with optimized imaging quality is multiplied by the intercepted signal transmitted from the SAR platform to obtain a modulated SAR deception jamming signal;

[0013] Step six, after digital-to-analog conversion and up-conversion processing of the modulated SAR deception jamming signal, the signal is forwarded to the target SAR system pulse by pulse.

[0014] Further, in step one, the measured signal parameters include the carrier frequency, the linear frequency modulation, the pulse width, the bandwidth, the pulse repetition frequency of the signal, and the instantaneous slant range between the SAR platform and the jammer.

[0015] Further, in step two, the Gaussian weighting window function is used for weighting processing on the edge area of the template image, and the weight value is determined by the Euclidean distance from a pixel point to the boundary of the predetermined rectangular area at the center of the image; the farther the distance is, the smaller the weight value is.

[0016] Furthermore, in step three, the two-dimensional block processing includes dividing the entire template image into multiple rectangular sub-regions of constant size and non-overlapping dimensions in two dimensions, based on the pre-analyzed maximum allowable block length in the range direction and the maximum allowable block width in the azimuth direction. The determination of the block size needs to consider the range and azimuth resolution of the SAR system, the tolerance for defocusing of point target imaging, and the real-time requirements of the entire system.

[0017] Furthermore, the maximum permissible block length in the range direction and the maximum permissible block width in the azimuth direction are determined by the following method: theoretical calculations are performed to ensure that the residual range migration of the farthest point target in each sub-template does not exceed one-quarter of the range cell after phase compensation, and that the second phase error in the azimuth direction does not exceed π / 4, as constrained by these conditions.

[0018] Furthermore, in step four, deriving the compensation coefficients includes, for each sub-template, taking the position of its geometric center point in the scene as a reference point, calculating the phase error generated by the position relative to the real point target echo due to two-dimensional frequency shift modulation at that position. The phase error includes a linear term related to azimuth time and a coupled term related to both distance time and azimuth time.

[0019] Furthermore, the phase compensation in step four includes: for each sub-template, generating a two-dimensional phase compensation function matrix determined by the compensation coefficient, and then performing a complex multiplication operation between the phase compensation function matrix and the complex data of the corresponding sub-template to complete the phase correction of all pixels of the sub-template.

[0020] On the other hand, the present invention provides a high-resolution SAR deception jamming signal rapid generation device, comprising:

[0021] The matrix calculation module is used to enable the jammer to intercept signals transmitted from the SAR platform, measure the signal parameters, and calculate the product modulation matrix that generates deception interference.

[0022] The optimization processing module is used to obtain the deception interference template image to be generated, and apply a Gaussian weighted window function to it for edge optimization processing as needed;

[0023] The block processing module is used to perform two-dimensional block processing on the optimized template image to obtain multiple non-overlapping sub-templates;

[0024] The phase compensation module is used to derive the compensation coefficients, perform phase compensation on the center position of each sub-template, and add up all the phase-compensated sub-templates to obtain the product modulation interference matrix after image quality optimization.

[0025] The jamming signal module is used to multiply the image quality-optimized product modulation jamming matrix with the intercepted signal transmitted by the SAR platform to obtain the modulated SAR deception jamming signal.

[0026] The output module is used to perform digital-to-analog conversion and up-conversion processing on the modulated SAR deception jamming signal, and then forward it to the target SAR system pulse by pulse.

[0027] Thirdly, the present invention provides an electronic device, comprising: one or more processors; and a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method for rapidly generating high-resolution SAR deception jamming signals.

[0028] Fourthly, the present invention provides a computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, enable the processor to implement the aforementioned method for rapidly generating high-resolution SAR deception jamming signals.

[0029] The beneficial effects of this invention are as follows:

[0030] This invention significantly improves the imaging quality and concealment of high-resolution SAR deception jamming by introducing two-dimensional block phase compensation and template edge optimization. Compared with existing technologies, this method effectively overcomes the defocusing problem caused by residual migration and frequency modulation mismatch in traditional methods while maintaining the advantages of low complexity and high real-time performance of product modulation jamming. This allows the jammed image to achieve imaging indicators close to those of the real point target under both spaceborne and airborne conditions. Simultaneously, the Gaussian-weighted edge optimization strategy effectively eliminates energy abrupt changes between the jammed area and the real background, achieving a smooth transition and significantly reducing the risk of manual identification. This invention achieves a significant improvement in imaging quality and deception success rate with controllable computational overhead, demonstrating strong engineering applicability. Attached Figure Description

[0031] Figure 1 This is a flowchart of a method for rapidly generating high-resolution SAR deception jamming signals according to the present invention;

[0032] Figure 2 This is a typical SAR deception and jamming scenario diagram;

[0033] Figure 3 A schematic diagram illustrating the generation process of the template matrix for deceiving and interfering signals;

[0034] Figure 4 This is a schematic diagram of the sub-template blocks used in the simulation experiment.

[0035] Figure 5 This is an image showing the imaging effect of five points in one of the sub-templates in a simulation experiment.

[0036] Figure 6 The images show the imaging effects of the center points of the sub-templates at four different locations in the simulation experiment;

[0037] Figure 7 An image illustrating the deception and interference effects in a spaceborne scenario;

[0038] Figure 8 An image illustrating the deception and interference effects in an airborne scenario;

[0039] Figure 9 A reference template diagram for deception and interference in spaceborne scenarios;

[0040] Figure 10 An image showing the deception jamming signal generated by a spaceborne jammer.

[0041] Figure 11 This is a reference template diagram for deception and interference in airborne scenarios;

[0042] Figure 12 An image illustrating the deception jamming signal generated by an airborne jammer.

[0043] Figure 13 Image showing the edge-free optimization of deception and interference signal imaging effect for airborne scenarios;

[0044] Figure 14 An image showing the edge-optimized deception and interference signal imaging effect for airborne scenarios;

[0045] Figure 15 This is a block diagram of a high-resolution SAR deception jamming signal rapid generation device according to the present invention. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] like Figure 1 As shown, this invention discloses a method for rapidly generating high-resolution SAR deception jamming signals, comprising the following steps:

[0048] Step 1: The jammer intercepts the signal transmitted from the SAR platform. After down-conversion and A / D conversion, the signal is stored in a digital radio frequency memory (DRFM). Parameters such as the carrier frequency, frequency modulation frequency, and azimuth angle are measured. The distance from the SAR platform to the jammer is determined through preliminary reconnaissance. These parameters are then used to generate a deceptive jamming product modulation matrix.

[0049] Step 2: Obtain the deception interference template image to be generated, and apply a Gaussian weighted window function to it for edge optimization processing as needed;

[0050] Step 3: Perform two-dimensional block processing on the optimized template image to obtain multiple non-overlapping sub-templates;

[0051] Step 4: Derive the compensation coefficients, perform phase compensation on the center position of each sub-template, and add up all the phase-compensated sub-templates to obtain the product modulation interference matrix after image quality optimization.

[0052] Step 5: Multiply the image quality-optimized product modulation interference matrix with the intercepted signal transmitted by the SAR platform to obtain the modulated SAR deception interference signal;

[0053] Step 6: After performing digital-to-analog conversion and up-conversion processing on the modulated SAR deception jamming signal, forward it to the target SAR system pulse by pulse.

[0054] The geometric model of the two-dimensional (2-D) frequency shift interference method is as follows: Figure 2 As shown. A coordinate system is established with the jammer's position as the origin. The flight direction of the synthetic aperture radar (SAR) platform is defined as the positive azimuth direction, denoted as... The positive direction of the axis lies in the slant distance plane, and the coordinate axes are... Defined as the slant range direction, which is perpendicular to the azimuth direction, the closest slant range from the synthetic aperture radar to the jammer is... The rate of the synthetic aperture radar platform is expressed as The synthetic aperture radar's beam direction is in front-looking side-view mode, and the scanning mode is in strip mode. The coordinates of the fake point target P generated by the jammer are represented as follows: .

[0055] The specific principle and implementation process of step one are as follows:

[0056] Echo signal generated at point target P by frequency shift It can be represented as:

[0057] (1)

[0058] Among them For distance to time, For direction and time, Represents the distance-to-window function. For azimuth window function, This represents the amplitude of the echo signal, where j represents the imaginary unit. Represents the speed of light. The carrier frequency representing the signal. The frequency modulation frequency represents the linear frequency modulation signal. The real-time slant range from the stationary point target at the location of the jammer to the SAR channel. This represents the frequency shift in the range direction. This indicates the frequency shift in the azimuth direction.

[0059] Due to the difference in the range migration (RCM) curves between the interference signal echo and the point target echo, the residual range migration of the interference signal remains uncorrected even after range cell migration correction (RCMC). Furthermore, the difference between the azimuth Doppler modulation frequency of the interference signal and the azimuth Doppler modulation frequency of the point target echo leads to modulation frequency mismatch in azimuth pulse compression. When the residual range migration and azimuth Doppler modulation frequency error are ignored, the signal after imaging using the range-Doppler (RD) imaging algorithm is represented as follows:

[0060] (2)

[0061] In the formula, This represents the amplitude of the signal after two-dimensional compression by SAR imaging. The azimuth-direction Doppler frequency modulation and the imaging signal expression (2) indicate that the two-dimensional frequency shift modulation interference introduces a positional offset in the range direction. Its expression is:

[0062] (3)

[0063] and a position offset along the azimuth direction :

[0064] (4)

[0065] in This indicates the speed of the SAR platform.

[0066] Therefore, the position of the dummy target satisfies .

[0067] When using this method to quickly generate deceptive interference scenarios, the fixed frequency shift component in the two-dimensional fixed frequency shift interference is replaced by a product-modulated waveform. The corresponding baseband interference echo signal can be represented as follows:

[0068] (5)

[0069] The product modulation waveform satisfy:

[0070] (6)

[0071] in, This indicates that the frequency in two dimensions is The backscattering coefficient value of the dummy target at the location.

[0072] Since the system response of synthetic aperture radar (SAR) imaging is independent of the two-dimensional frequency shift, equation (5) can be simplified to the following form:

[0073] (7)

[0074] Where Img{} represents the SAR imaging operation performed on the echo within the brackets.

[0075] However, in the case of large-scale deception interference in high-resolution SAR systems, as the offset distance increases, the point target defocusing caused by residual range migration and Doppler frequency modulation mismatch will lead to a significant decrease in imaging quality.

[0076] Therefore, in order to improve the accuracy of this deception jamming method in high-resolution SAR scenarios, it is necessary to compensate for the error introduced by the frequency shift jamming relative to the echo of the real target at the same location without significantly increasing the computational complexity.

[0077] The specific implementation process of step two is as follows:

[0078] First, analyze the exact error of the point target. As shown in step one, equation (1) can be applied to the location... Generate false point targets. Real point targets are... The echo expression at that point can be represented as:

[0079] (8)

[0080] in:

[0081] (9)

[0082] (10)

[0083] in, Indicates the SAR platform speed. This indicates the slant range of the generated false point target to the SAR when the jammer is at the closest slant range to the SAR.

[0084] Therefore, the phase of the real point target is represented as:

[0085] (11)

[0086] Furthermore, the phase of the interference signal in equation (1) is expressed as:

[0087] (12)

[0088] The phase error between the interference signal at the interference location and the actual target point can be calculated as follows:

[0089] (13)

[0090] in:

[0091] (14)

[0092] First, (13) can be divided into two parts:

[0093] (15)

[0094] and

[0095] (16)

[0096] Formula (15) is only related to azimuth time, while formula (16) is related to two-dimensional time. By moving the term in (16) that is only related to η to (15) and ignoring the constant term, we can obtain:

[0097] (17)

[0098] and

[0099] (18)

[0100] Among them are:

[0101] (19)

[0102] Observations have revealed that in specific SAR systems, All remain constant. For a specific sub-template, and The value also remains constant.

[0103] Through compensation and The phase of the echo signal generated by the jammer can highly simulate the phase of the real target point at a specific location. However, given that the significant increase in computational complexity is unacceptable, phase optimization for all target points is not possible in deceptive jamming scenarios.

[0104] Furthermore, in practical applications, jamming templates are typically extracted from existing synthetic aperture radar (SAR) images. These templates not only contain the central target used for deception jamming but also surrounding terrain features near the edges. If such extracted templates are directly used to generate deceptive jamming, a significant discontinuity often appears in the SAR imaging region at the boundary between the jammed area and the real scene. This boundary discontinuity may make the deceptive jamming easier to identify. Therefore, a Gaussian distance attenuation weighting function can be constructed to gradually reduce the energy at the edges of the jamming template, thereby achieving a smooth energy transition between the deceptive jamming region and the surrounding area. Assuming the pixel size of the template image is... The size of the central rectangular area is set to... , where the coefficient and Used to adjust size. Outside this rectangular area, the energy value gradually decreases towards the edges. Each pixel in the image. The distance to the boundary of the central rectangular region is:

[0105] (20)

[0106] and

[0107] (twenty one)

[0108] in, This represents the distance in pixels from the upward-facing pixel to the boundary of the central rectangle. This represents the distance from the upward-facing pixel to the pixel boundary of the central rectangle.

[0109] Therefore, the Euclidean distance from a point in the template to the central rectangular region can be expressed as:

[0110] (twenty two)

[0111] Then, a function can be constructed whose weights decrease as the distance from the central rectangular region increases:

[0112] (twenty three)

[0113] in, It is a Gaussian parameter used to control the attenuation range.

[0114] Finally, a weighted mask is applied to the template image to perform pixel-level weighting:

[0115] (twenty four)

[0116] in, This represents the original template. This represents the optimized template image.

[0117] Finish and After phase compensation, the imaging quality of the center of each sub-template approaches that of the ideal point target. However, the phase error increases with the increase of distance from the center. Therefore, the dimensional constraints can be determined using the point furthest from the center in the sub-template. Taking the center of the sub-template as the reference point, assume that the furthest point is offset along the coordinate axis direction by... and Range. Specifically, the range resolution of SAR is... The azimuth resolution is The frequency offset corresponding to the two-dimensional offset can be expressed as:

[0118] (25)

[0119] (26)

[0120] in, Indicates Doppler frequency modulation. Indicates the SAR signal frequency modulation. It represents the speed of light. Indicates the azimuth frequency shift. This represents the distance-direction frequency shift.

[0121] When formula (1) is processed using a SAR imaging algorithm, the range migration (RCM) of (1) in the range-Doppler domain of the reference point is calculated as follows:

[0122] (27)

[0123] The reference point is located at the position of the dummy target, and the RCM of the reference point is:

[0124] (28)

[0125] Then, ignoring the constant part, the residual distance migration is calculated as follows:

[0126] (29)

[0127] In (29), The impact is far greater than .when When restricted to values ​​close to zero, we have:

[0128] (30)

[0129] Within a synthetic aperture length The maximum value appears ,in , It is the antenna length along the azimuth direction. If Less than or equal to If the range resolution is doubled, then:

[0130] (31)

[0131] in, A coefficient representing the degree of defocusing along the distance direction of modulation.

[0132] Therefore, when , The constraints are expressed as:

[0133] (32)

[0134] Furthermore, errors in the azimuth Doppler frequency modulation can lead to mismatch in the azimuth matched filter, causing azimuth defocusing of point targets. This limits the block length in the range direction. The jammer's azimuth frequency modulation is:

[0135] (33)

[0136] The azimuth tuning frequency at the dummy target location is:

[0137] (34)

[0138] A suitable method for quantizing impulse response width (IRW) broadening is to calculate the second-order phase error (QPE), which is defined as:

[0139] (35)

[0140] in, This represents a synthesis aperture time.

[0141] To control IRW broadening along the azimuth direction, QPE needs to meet the following conditions:

[0142] (36)

[0143] in, The modulation coefficient represents the degree of broadening along the azimuth direction.

[0144] (37)

[0145] Based on formulas (32) and (37) and resolution and To ensure the imaging quality of each point within each sub-template, the number of two-dimensional pixels in each sub-template is represented as follows:

[0146] (38)

[0147] (39)

[0148] in, This indicates the number of pixel rows in the orientation direction of a single sub-template, while This indicates the number of pixel columns in the upward direction of a single sub-template.

[0149] With coefficient and As the size of the template increases, the area of ​​each sub-template gradually expands, leading to a gradual decrease in image quality. Conversely, decreasing the size of the template... and This can improve the imaging quality of each sub-template. However, reducing the area will lead to an increase in the number of sub-templates, thereby increasing the overall computational complexity.

[0150] The specific implementation process of step three is as follows:

[0151] Based on the two-phase optimization strategy described above, this invention proposes a product modulation spoofing interference optimization algorithm to improve imaging quality in high-resolution and large-scale spoofing interference scenarios. The generation process of the spoofing interference template is as follows: Figure 3 As shown.

[0152] First, a scene image for deception and jamming is selected. In the two-dimensional spatial domain, each pixel corresponds to a specific point target in the SAR image, and its pixel amplitude represents the backscattering coefficient at that location. Subsequently, as... Figure 3 As shown in the red box, select a two-dimensional rectangular region of appropriate size, which includes the azimuth dimension. 1 pixel, containing in the distance dimension Each pixel. For pixels outside the selected area, the amplitude value is set to 0.

[0153] The specific implementation process of step four is as follows:

[0154] Next, based on the time-frequency transformation relations (3) and (4), the sub-templates in the two-dimensional spatial domain can be mapped to the frequency domain. Then, they are converted to the frequency domain using a two-dimensional inverse fast Fourier transform (IFFT). A two-dimensional temporal sub-template of size, where This indicates the number of sampling points in the azimuth direction of the jammer. This represents the number of sampling points in the distance from the jammer. Next, the two phase compensation terms (17) and (18) are multiplied by the two-dimensional temporal sub-template respectively. By traversing all non-overlapping regions in the image, k optimized sub-templates are finally obtained, such as... Figure 3As shown. Adding these sub-templates together yields the matrix of product modulation interference after image quality optimization. .

[0155] The specific implementation process of step five is as follows:

[0156] Multiplying the total template with the intercepted signal yields the optimized baseband interference signal.

[0157] (40)

[0158] The theoretical model of this invention will be verified and analyzed below based on simulation results. Setting the Objective The system operates in strip frontal and side-view imaging mode, with an operating frequency band of [frequency band missing]. Band. Under airborne conditions, the slant distance from the SAR platform to the scene center is 25544.7m, and the SAR aircraft's flight speed is 154.2m / s. The SAR signal carrier frequency is 9.6GHz, the signal bandwidth is 480MHz, and the pulse duration is... The pulse repetition frequency is 533.3 Hz. The synthetic aperture length is 1021.8 m, the range resolution is 0.277 m, and the azimuth resolution is 0.346 m. ​​Under spaceborne conditions, the slant distance from the SAR platform to the scene center is 850 km, and the SAR aircraft's flight speed is 7100 m / s. The SAR signal carrier frequency is 9.6 GHz, the signal bandwidth is 67 MHz, and the pulse duration is... The pulse repetition frequency is 3400 Hz. The synthetic aperture length is 5883.6 m, the range resolution is 2.0 m, and the azimuth resolution is 2.0 m.

[0159] exist Figure 4 In the diagram, a 40×100 pixel interference template is evenly divided into four blocks. P1 is the center point of the template, P2 is the center point of one of the sub-templates, and P5 is one of the points farthest from P2. Figure 5 Yes Figure 4 The diagram shows the effect of using a block-based approach for deception and interference imaging. Experimental results show that, under high-resolution airborne SAR parameters, the optimized template imaging quality is significantly improved compared to the unoptimized version. However, the imaging quality in the edge regions of the sub-templates still shows a downward trend. Therefore, it is necessary to adjust the number and size of the sub-blocks according to specific application requirements to ensure that the imaging quality meets the requirements of the specific application scenario without significantly increasing the computational and storage burden.

[0160] Figure 6 In this example, a 900-pixel × 900-pixel template is evenly divided into nine sub-templates. Four of these sub-templates are selected, and their center points are used for analysis. For example... Figure 6 As shown, , , and These represent the center points of the selected sub-templates. Figure 7 This is a template imaging effect diagram of optimized product modulation deception interference under spaceborne parameter scenarios. Figure 8 This image shows the optimized product modulation deception jamming template imaging results under airborne parameter scenarios. Under both spaceborne and airborne conditions, the imaging of the sub-template center point meets the two-dimensional resolution, integral sidelobe ratio, and peak sidelobe ratio requirements for ideal point target imaging under the corresponding parameters. It can be observed that the optimized product modulation deception jamming method achieves high imaging quality for the sub-template reference point under both spaceborne and airborne conditions.

[0161] Using template two-dimensional division In a block-based manner, Figure 9 The reference template image for deception and interference in spaceborne scenarios serves as the interference template. The method of this invention is used for deception and interference imaging. The imaging results are as follows: Figure 10 As shown, the structural similarity (SSIM) between the original template diagram and the actual template diagram is 0.893. Figure 11 The reference template image for deception and jamming in airborne scenarios is used as the jamming template. Deception and jamming imaging is performed using the method of this invention. The imaging results are as follows: Figure 12 As shown, the structural similarity (SSIM) between the original template image and the actual image is 0.897. This demonstrates that the method of this invention can produce high-quality deception / jamming images under both spaceborne and airborne high-resolution SAR conditions.

[0162] Figure 13 This is a deception interference imaging image without edge optimization and phase optimization. Figure 14 The image shown is the result of edge optimization. It can be observed that after edge optimization, the edge regions of the image used to deceive interference can transition well with the real background, rather than exhibiting characteristics like... Figure 13 The same discontinuity at the edges. Smooth edges blend into the real ground background, thus reducing the likelihood of interference detected by humans.

[0163] On the other hand, the present invention provides a high-resolution SAR deception jamming signal rapid generation device, which includes various modules capable of implementing the various steps of the aforementioned method, including:

[0164] The matrix calculation module is used to enable the jammer to intercept signals transmitted from the SAR platform, measure the signal parameters, and calculate the product modulation matrix that generates deception interference.

[0165] The optimization processing module is used to obtain the deception interference template image to be generated, and apply a Gaussian weighted window function to it for edge optimization processing as needed;

[0166] The block processing module is used to perform two-dimensional block processing on the optimized template image to obtain multiple non-overlapping sub-templates;

[0167] The phase compensation module is used to derive the compensation coefficients, perform phase compensation on the center position of each sub-template, and add up all the phase-compensated sub-templates to obtain the product modulation interference matrix after image quality optimization.

[0168] The jamming signal module is used to multiply the image quality-optimized product modulation jamming matrix with the intercepted signal transmitted by the SAR platform to obtain the modulated SAR deception jamming signal.

[0169] The output module is used to perform digital-to-analog conversion and up-conversion processing on the modulated SAR deception jamming signal, and then forward it to the target SAR system pulse by pulse.

[0170] like Figure 15 As shown, its specific composition can also be:

[0171] The signal reception module is used to detect and receive signals transmitted by the target SAR system.

[0172] The downconversion module is used to perform downconversion processing on the received SAR signal;

[0173] The analog-to-digital converter module is used to convert the intercepted target SAR transmitted signals into digital signals.

[0174] The signal parameter measurement module is used to measure signal parameters such as pulse width, bandwidth, and pulse repetition frequency of the received signal.

[0175] The template edge optimization and segmentation module is used to smooth template edges and divide the original template into appropriately sized segments.

[0176] The sub-template phase compensation and superposition module is used to optimize the phase of each sub-template, and then superimpose all the optimized sub-templates to obtain the final product modulation matrix of the template.

[0177] The template modulation matrix multiplication module is used to multiply the optimized product modulation matrix with the intercepted SAR signal to obtain the final digital signal of the deception jamming signal.

[0178] The digital-to-analog converter module converts the acquired digital interference signal into an analog signal;

[0179] The upconversion module is used for upconversion processing of analog interference signals;

[0180] The transmitting module is used to transmit interference signals pulse by pulse.

[0181] Thirdly, the present invention provides an electronic device, comprising: one or more processors; and a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method for rapidly generating high-resolution SAR deception jamming signals.

[0182] Fourthly, the present invention provides a computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, enable the processor to implement the aforementioned method for rapidly generating high-resolution SAR deception jamming signals.

[0183] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for rapidly generating high-resolution SAR deception jamming signals, characterized in that, The method includes: Step 1: The jammer intercepts the signal transmitted from the SAR platform, measures the signal parameters, and calculates the product modulation matrix that generates deception interference. Step 2: Obtain the deception interference template image to be generated, and apply a Gaussian weighted window function to it for edge optimization processing as needed; Step 3: Perform two-dimensional block processing on the optimized template image to obtain multiple non-overlapping sub-templates; Step 4: Based on the analytical expression of the phase error between the interference signal and the real target echo in the two-dimensional frequency shift interference model, derive the compensation coefficient consisting of the azimuth-time linear term and the range-azimuth coupling term; for each sub-template, using its geometric center as the reference point, generate a two-dimensional phase compensation function matrix containing the compensation coefficient; multiply this matrix with the complex data of the corresponding sub-template to complete the phase correction of all pixels of the sub-template at the baseband signal level; sum all the phase-corrected sub-templates to obtain the product modulation interference matrix after image quality optimization; Step 5: Multiply the image quality-optimized product modulation interference matrix with the intercepted signal transmitted by the SAR platform to obtain the modulated SAR deception interference signal; Step 6: After performing digital-to-analog conversion and up-conversion processing on the modulated SAR deception jamming signal, forward it to the target SAR system pulse by pulse.

2. The method for rapidly generating high-resolution SAR deception jamming signals according to claim 1, characterized in that, In step one, the measured signal parameters include the carrier frequency, linear modulation frequency, pulse width, bandwidth, pulse repetition frequency, and instantaneous slant range between the SAR platform and the jammer.

3. The method for rapidly generating high-resolution SAR deception jamming signals according to claim 1, characterized in that, In step two, the Gaussian weighted window function is used to weight the edge region of the template image. The weight is determined by the Euclidean distance from the pixel to the boundary of the predetermined rectangular region in the center of the image. The farther the distance, the smaller the weight.

4. The method for rapidly generating high-resolution SAR deception jamming signals according to claim 1, characterized in that, In step three, the two-dimensional block processing includes dividing the entire template image into multiple rectangular sub-regions of constant size and non-overlapping dimensions in two dimensions, based on the pre-analyzed maximum allowable block length in the range direction and the maximum allowable block width in the azimuth direction. The determination of the block size needs to consider the range and azimuth resolution of the SAR system, the tolerance for defocusing of point target imaging, and the real-time requirements of the entire system.

5. The method for rapidly generating high-resolution SAR deception jamming signals according to claim 4, characterized in that, The maximum permissible block length in the range direction and the maximum permissible block width in the azimuth direction are determined by the following method: theoretical calculations are performed to ensure that the residual range migration of the farthest point target in each sub-template does not exceed one-quarter of the range cell after phase compensation, and that the second phase error in the azimuth direction does not exceed π / 4, as constrained by these conditions.

6. A device for rapidly generating high-resolution SAR deception jamming signals, characterized in that, include: The matrix calculation module is used to enable the jammer to intercept signals transmitted from the SAR platform, measure the signal parameters, and calculate the product modulation matrix that generates deception interference. The optimization processing module is used to obtain the deception interference template image to be generated, and apply a Gaussian weighted window function to it for edge optimization processing as needed; The block processing module is used to perform two-dimensional block processing on the optimized template image to obtain multiple non-overlapping sub-templates; The phase compensation module is used to derive compensation coefficients composed of azimuth-time linear terms and range-azimuth coupling terms based on the analytical expression of the phase error between the interference signal and the real target echo in the two-dimensional frequency shift interference model. For each sub-template, a two-dimensional phase compensation function matrix containing the compensation coefficients is generated with its geometric center as the reference point. This matrix is ​​then multiplied by the complex data of the corresponding sub-template to complete the phase correction of all pixels of the sub-template at the baseband signal level. All phase-corrected sub-templates are summed to obtain the product modulation interference matrix after image quality optimization. The jamming signal module is used to multiply the image quality-optimized product modulation jamming matrix with the intercepted signal transmitted by the SAR platform to obtain the modulated SAR deception jamming signal. The output module is used to perform digital-to-analog conversion and up-conversion processing on the modulated SAR deception jamming signal, and then forward it to the target SAR system pulse by pulse.

7. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When one or more programs are executed by the one or more processors, the one or more processors implement the high-resolution SAR deception jamming signal rapid generation method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, It stores executable instructions that, when executed by a processor, enable the processor to implement the high-resolution SAR deception jamming signal rapid generation method according to any one of claims 1-5.

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