SAR interference method based on phase modulation corner reflector

Abstract

The invention discloses an SAR (Synthetic Aperture Radar) interference method based on a phase modulation corner reflector. The SAR interference method comprises the following steps: acquiring an echo signal; wherein the echo signal comprises a nonlinear phase modulation item introduced through a metasurface corner reflector; performing range direction processing on the echo signal to obtain a complex signal sequence; performing motion compensation on the complex signal sequence, and obtaining a mixed azimuth spectrum through Fourier transform; performing azimuth matched filtering based on the mixed azimuth spectrum to obtain a filtered signal; and performing phase error estimation on the filtered signal by using a PGA algorithm, and compensating the filtered signal by using the estimated phase error to obtain a defocused image, thereby providing the SAR interference method with good regional interference effect and hidden interference source.

Description

A SAR jamming method based on phase-modulated angle reflectors Technical Field

[0001] This invention belongs to the field of radar technology, specifically relating to a SAR (Synthetic Aperture Radar) jamming method based on a phase-modulated corner reflector. Background Technology

[0002] Traditional electronic countermeasures have revealed significant shortcomings in modern radar detection environments. Ordinary corner reflectors have limited jamming effects against synthetic aperture radar. The radar characteristics of radar simulating real targets are easily identified, reducing the effectiveness of multi-mode jamming against real targets. Deployment locations are limited by open terrain, making it difficult to conceal in complex environments such as urban clusters and mountains, and easy to be detected. Strong echo source focal decoys cannot create fully false target identification, resulting in weak overall suppression effects and limiting their use to area jamming techniques.

[0003] Ordinary corner reflectors have limited jamming effect on pulse synthetic aperture radar (SAR), and their simulated radar characteristics are easily identifiable. They cannot match the terrain patterns of complex scenarios due to the fixed echo characteristics of SAR radar, thus reducing jamming effectiveness. Their deployment locations are limited to open areas, making them easily detectable by optical reconnaissance. Strong echo signals have fixed characteristics, making them easy for the enemy to trace and locate the signal source. They can only achieve single-point deception and cannot create area suppression effects, thus limiting their operational effectiveness in modern electronic warfare.

[0004] Patent document CN117630829A, entitled "Method, Apparatus, and Hidden Corner Reflector for Changing the Target Characteristics of a Hidden Corner Reflector," discloses a method for changing the target characteristics of a hidden corner reflector. This method includes: obtaining a preset RCS adjustment value δ; obtaining the transmittance α of the electromagnetic wave resistance control material; and determining the size of the corner reflector array based on the adjustment value δ and the transmittance α, such that the RCS of the corner reflector array in the horizontal direction is greater than or equal to the preset value. This method allows for the camouflage of corner reflectors placed on the surface of an object, making the camouflage difficult to detect by optical means. It also discloses a device for changing the target characteristics of a hidden corner reflector and a hidden corner reflector. However, this method still has shortcomings. While it primarily addresses the problem of optical identification concealment, it does not mention the interference concealment effect on synthetic aperture radar, limiting its applicability.

[0005] For existing synthetic aperture radars, existing corner reflectors have poor jamming effects and small jamming ranges. They are only effective against low-resolution radars, which are easily identified, and cannot effectively interfere with the imaging area. They are basically ineffective against high-precision radars and have limited adaptability. Ordinary corner reflectors cause regular interference to the echo phase. After being processed by the autofocus algorithm of synthetic radar, the focused angle is identified as a clear false target, and the radar can still identify other targets in the area, resulting in poor jamming effects.

[0006] Therefore, how to provide a SAR jamming method with good regional jamming effect and concealed jamming source for use in adversarial training has become an important issue. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides a SAR jamming method based on a phase-modulated angle reflector.

[0008] The technical problem to be solved by the present invention is achieved through the following technical solution: Firstly, the present invention provides a SAR jamming method based on a phase-modulated corner reflector. The SAR jamming method includes: acquiring an echo signal; wherein the echo signal includes a nonlinear phase modulation term introduced by a metasurface corner reflector; performing range processing on the echo signal to obtain a complex signal sequence; performing motion compensation on the complex signal sequence and obtaining a mixed azimuth spectrum through Fourier transform; performing azimuth-matched filtering based on the mixed azimuth spectrum to obtain a filtered signal; using the PGA algorithm to estimate the phase error of the filtered signal, and using the estimated phase error to compensate for the filtered signal to obtain a defocused image, thereby achieving SAR jamming.

[0009] Optionally, acquiring the echo signal includes: receiving the real target echo signal from the radar; superimposing the real target echo signal with an interference echo signal generated by a metasurface corner reflector to obtain the echo signal; the interference echo signal is generated based on a nonlinear phase modulation term.

[0010] Optionally, range processing is performed on the echo signal to obtain a complex signal sequence, including: range pulse compression and range migration correction of the echo signal to obtain a complex signal sequence.

[0011] Optionally, the nonlinear phase modulation term includes second-order or higher phase modulation terms.

[0012] Optionally, the nonlinear phase modulation term is a quadratic phase modulation term; the quadratic phase modulation term includes: ;in, This represents the second phase modulation term; Represents the imaginary unit; Indicates frequency modulation; Indicates direction and time.

[0013] Optionally, the echo signal includes: ;in, This refers to the echo signal; , Indicates the number of scattering sources; Indicates the scattering coefficient; Indicates the echo signal of a point target; , Indicates the number of echoes from a metasurface corner reflector; Indicates the first Scattering coefficient of a metasurface corner reflector; Indicates the first Ideal point target echo signal of a metasurface corner reflector; Indicates the first The instantaneous slant range of each scattering source; Indicates the first Instantaneous slant range of a metasurface corner reflector; symbol Indicates parameter separator; Indicates direction and time.

[0014] Secondly, the present invention provides a SAR jamming device based on a phase-modulated corner reflector. The SAR jamming device includes: an acquisition module for acquiring an echo signal, wherein the echo signal includes a nonlinear phase modulation term introduced by a metasurface corner reflector; a processing module for performing range processing on the echo signal to obtain a complex signal sequence; a motion compensation module for performing motion compensation on the complex signal sequence and obtaining a mixed azimuth spectrum through Fourier transform; a filtering module for performing azimuth-matched filtering based on the mixed azimuth spectrum to obtain a filtered signal; and a compensation module for estimating the phase error of the filtered signal using a PGA algorithm and compensating the filtered signal using the estimated phase error to obtain a defocused image, thereby achieving SAR jamming.

[0015] Thirdly, the present invention provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory is used to store computer programs; and the processor, when executing the computer program stored in the memory, implements the steps of any of the above-mentioned SAR jamming methods based on phase modulation angle reflectors.

[0016] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of any of the above-described SAR jamming methods based on a phase-modulated angle reflector.

[0017] The SAR jamming method based on a phase-modulated corner reflector provided by this invention includes a nonlinear phase modulation term introduced by the metasurface corner reflector in the acquired echo signal. This nonlinear phase modulation term can lead to the estimation of a distorted phase error in the subsequent PGA algorithm. When this phase error is used for whole-image compensation, not only the interference source itself, but also the target in the entire imaging area will become defocused, elevating the traditional point target deception jamming to an overall suppression jamming of the imaging area, thereby improving the jamming effect and making it difficult to detect.

[0018] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 is a flowchart illustrating a SAR jamming method based on a phase modulation angle reflector according to an embodiment of the present invention; Figure 2 is a flowchart illustrating another SAR jamming method based on a phase modulation angle reflector according to an embodiment of the present invention; Figure 3 is a cross-sectional view without jamming; Figure 4 is a cross-sectional view with jamming; Figure 5 is a comparative diagram of measured data before and after jamming; Figure 6 is a structural schematic diagram of a SAR jamming device based on a phase modulation angle reflector according to an embodiment of the present invention; Figure 7 is a structural schematic diagram of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0021] To address the problems of poor interference effect and easy identification of existing SAR jamming methods, this invention provides a SAR jamming method based on a phase-modulated corner reflector. Referring to Figure 1, which is a flowchart of a SAR jamming method based on a phase-modulated corner reflector provided by this invention, the specific steps are as follows: Step S101, acquire the echo signal; wherein, the echo signal includes nonlinear phase modulation introduced through a metasurface corner reflector.

[0022] In this embodiment of the invention, obtaining the echo signal includes: receiving the real target echo signal from the radar; superimposing the real target echo signal with an interference echo signal generated by a metasurface corner reflector to obtain the echo signal; the interference echo signal is generated based on a nonlinear phase modulation term.

[0023] In this embodiment of the invention, the radar's actual target echo signal include: ;in, Indicates distance to time; Indicates direction and time; express The slant distance at any given time; Represents the speed of light; Indicates the pulse duration; Indicates the moment when the beam center crosses; Indicates the time for synthesizing the aperture; Represents the imaginary unit; Indicates the radar carrier frequency; Indicates the range-directed frequency modulation; Represents a rectangular function; The natural exponential function is represented. In this embodiment of the invention, the echo signal can be obtained by superimposing the interference echo signal generated by the metasurface corner reflector on the real target echo signal.

[0024] Specifically, the interference echo signals generated by adding N metasurface corner reflectors to the entire scene can be represented as follows: ;in, Indicates the echo signal; , This indicates the number of scattering sources, i.e., the number of point targets. Indicates the scattering coefficient; Indicates the echo signal of a point target; , Indicates the number of echoes from a metasurface corner reflector; Indicates the first Scattering coefficient of a metasurface corner reflector; Indicates the first Ideal point target echo signal of a metasurface corner reflector; Indicates the first The instantaneous slant range of each scattering source; Indicates the first Instantaneous slant range of a metasurface corner reflector; symbol Indicates the parameter separator.

[0025] This represents the nonlinear phase modulation term introduced by the metasurface corner reflector. The nonlinear phase modulation term includes second-order and higher phase modulation terms because the first-order phase is not compensated in the PGA (Phase Gradient Autofocusing Algorithm).

[0026] In this embodiment of the invention, the simplest quadratic phase can be used as an example. Derivation: ;in, This refers to the frequency modulation, which is the additional or spurious azimuth frequency modulation generated by the metasurface corner reflector.

[0027] Step S102: Perform range processing on the echo signal to obtain a complex signal sequence.

[0028] Referring to Figure 2, which is a flowchart of another SAR jamming method based on a phase-modulated corner reflector provided in an embodiment of the present invention, the method involves performing range processing on the echo signal to obtain a complex signal sequence, including: performing range pulse compression and range migration correction on the echo signal to obtain a complex signal sequence.

[0029] In this embodiment of the invention, the initial complex signal sequence is obtained by performing range pulse compression and range migration correction on the echo signal. include: ;in, Indicates signal bandwidth; Indicates distance to time; Indicates the target slant distance; Represents the speed of light; This represents the Singer function; since subsequent operations do not involve distance and time, the distance and time terms are ignored, resulting in a complex signal sequence for the entire scene. It can be: ;in, Indicates the first The signal after pulse compression and range migration correction of the scattering source; Indicates the first The azimuth signal of a metasurface corner reflector is corrected by range pulse compression and range migration.

[0030] Step S103: Motion compensation is performed on the complex signal sequence, and the mixed azimuth spectrum is obtained through Fourier transform.

[0031] In this embodiment of the invention, motion compensation is performed on the complex signal sequence, and a mixed azimuth spectrum is obtained through Fourier transform, as follows: Since SAR is mounted on an aircraft or satellite, its actual flight trajectory cannot be a perfect straight line; various minute offsets and fluctuations will exist. In this embodiment of the invention, compensation is performed for the additional errors caused by non-linear motion in the echo signal. After compensation, it is assumed that the SAR's flight path is a straight line, and the SAR's position is... ,in, Indicates the flight speed of the radar platform; Indicates direction and time; Represents fixed coordinates in the distance direction; Indicates the radar platform's flight altitude; the point target's position is... , Indicates the position of a point target in the azimuth direction; Indicates the target's position in the distance direction; Indicates the height of the point target; Indicates the radar platform and the first The scattering sources, i.e., the instantaneous slant range between point targets, This represents the instantaneous slant range between the radar platform and the nth metasurface corner reflector.

[0032] Among them, the radar platform and the first The instantaneous slant distance between the scattering sources is: ;in, Indicates the nearest slope distance.

[0033] and The formula is the same.

[0034] Because inertial navigation data contains errors, motion compensation cannot completely compensate for these errors. Furthermore, factors such as electromagnetic wave propagation can also introduce phase errors.

[0035] Assuming that the remaining phase error after motion error compensation is It is assumed that it has no spatial variation in the range direction, which is also the assumption of PGA. The advantage of this is that the azimuth Fourier transform becomes simple and efficient.

[0036] Will Substituting the complex signal sequence into the equation, performing motion compensation, and then performing a Fourier transform from the azimuth time domain to the Doppler domain, we can obtain the mixed azimuth spectrum, which includes: ;in, Indicates the mixed azimuth spectrum; Indicates the azimuth Doppler frequency; This represents the azimuth signal bandwidth of the original scattering source; Indicates the azimuth modulation frequency of the original scattering source; Indicates the azimuth signal bandwidth of the metasurface; This indicates the azimuth tuning frequency of the metasurface.

[0037] Step S104: Perform azimuth matched filtering based on the mixed azimuth spectrum to obtain the filtered signal.

[0038] In this embodiment of the invention, azimuth compression is performed based on a hybrid azimuth spectrum using an azimuth-matched filter, wherein the azimuth-matched filter is: ;in, This represents the frequency domain response of the azimuth matched filter; in this embodiment of the invention, the azimuth matched filter is not limited by a rectangular window. After multiplication, the resulting filtered signal... include: ;in, Indicates the phase generated by motion error; Indicates the bearing and position of the false target; Due to the mismatch in azimuth frequency modulation, the affected point will retain the interference phase, which will affect the subsequent PGA's estimation of the error phase. Since the interference echo comes from the corner reflector, the reflection coefficient of the affected target will be much greater than that of the surrounding points, ensuring that it will be selected by the PGA.

[0039] Step S105: The PGA algorithm is used to estimate the phase error of the filtered signal, and the estimated phase error is used to compensate for the filtered signal to obtain a defocused image and realize SAR interference.

[0040] In this embodiment of the invention, the PGA algorithm selects the strongest scattering point, such as a metasurface corner reflector, to estimate the phase error. However, interference with the phase distorts the estimated value, resulting in: ;in, This represents the estimated phase error; This represents the residual phase after motion error compensation; This indicates the number of interference points. These points typically include strong interference sources and some real, strong targets. The filtered signal is compensated using the estimated phase error, and an inverse Fourier transform is performed to obtain the defocused image. ;in, This represents the azimuth time-domain signal, i.e., the defocused image; , .

[0041] As can be seen from the above equation, the signal after azimuth compression should originally be a sinc function, but it becomes a rect function, which will cause defocusing in the azimuth direction. This degrades the focus quality of the entire image, achieving an interference effect.

[0042] In this embodiment of the invention, the acquired echo signal includes a nonlinear phase modulation term introduced by the metasurface corner reflector. This nonlinear phase modulation term can lead to the estimation of a distorted phase error in the subsequent PGA algorithm. When this phase error is used for whole-image compensation, not only the interference source itself, but also the target in the entire imaging area will become defocused, elevating the traditional point target deception interference to an overall suppression interference of the imaging area, thereby improving the interference effect and making it more difficult to detect and more concealed.

[0043] Furthermore, since the interference effect is achieved by influencing the algorithm in the signal processing domain, it ultimately manifests as a general, irregular degradation of image quality, rather than a sudden, strong reflection point. This effectively hides the location information of the interference source, namely the metasurface corner reflector.

[0044] The SAR jamming achieved in this invention provides a novel and highly realistic threat model for the research of radar system defense technology. Subsequent targeted adversarial training can be conducted based on this model to improve the radar's target detection and identification capabilities when facing advanced phase modulation jamming. This is of great value for improving the anti-jamming algorithm of radar systems and comprehensively enhancing their defensive performance.

[0045] A simulation experiment was conducted using a SAR jamming method based on a phase-modulated corner reflector provided in this embodiment of the invention. The results are as follows: Referring to Figure 3, which is a schematic diagram of the unjammed cross-section, a point target simulation experiment was performed. Jamming sources with and without surface covering were applied to the target. The specific parameter indices of the target before and after jamming are as follows: Referring to Table 1, which shows the center-range indices of the unjammed point target: Table 1 Center-range indices of the unjammed point target

[0046] See Table 2, which lists the azimuth indicators of uninterrupted target points: Table 2: Azimuth Indicators of Uninterrupted Target Points

[0047] The parameters for this point in the range direction are: peak sidelobe ratio of -13.0105 dB, integral sidelobe ratio of -10.3063 dB, and resolution of 0.1547 m. The parameters in the azimuth direction are: peak sidelobe ratio of -13.2511 dB, integral sidelobe ratio of -9.8291 dB, and resolution of 0.1031 m.

[0048] Refer to Figure 4, which is a schematic diagram of the interference profile. The range indices of the point targets after interference are shown in Table 3: Table 3 Range Indices of Point Targets After Interference

[0049] The azimuth indicators of point targets after adding interference are shown in Table 4: Table 4 Azimuth Indicators of Point Targets after Adding Interference

[0050] The parameters for this point in the range direction are: peak sidelobe ratio of -12.9902 dB, integral sidelobe ratio of -10.2988 dB, and resolution of 0.1581 m. The parameters in the azimuth direction are: peak sidelobe ratio of -1.1303 dB, integral sidelobe ratio of 7.2543 dB, and resolution of 0.0963 m. After adding corner reflector interference, both the range and azimuth directions show defocusing, with severe defocusing in the azimuth direction.

[0051] In this embodiment of the invention, the interference from the metasurface-covered corner reflector will interfere with the autofocusing part of the synthetic aperture radar. By affecting the selection of strong scattering points, it will affect the phase interference generated by the subsequent corner reflector. After multiple iterations, the phase influence will be greater, which will not only cause the autofocusing to fail, but also result in a worse focusing effect.

[0052] Refer to Figure 5, which is a schematic diagram comparing the measured results before and after interference. The simulation parameters for the PGA interference method based on the phase-modulated angle reflector are shown in Table 5: Table 5 Simulation Parameters for the PGA Interference Method Based on the Phase-Modulated Angle Reflector

[0053] As shown in Figure 5, the similarity between the two images is 0.2046, which can achieve a good interference effect.

[0054] In this embodiment of the invention, a novel metasurface-covered corner reflector is designed to replace the ordinary corner reflector, achieving regional interference through deceptive interference. The interfering corner reflector can be placed arbitrarily and can be changed at any time without revealing the location information of the interference source. The interference phase distorts the phase estimated by the PGA, causing the image after PGA to defocus, including both the original image and the interference point, thus achieving a better interference effect and suppressing regional interference rather than interfering with a specific point location. This also causes the focusing effect of the PGA algorithm for synthetic aperture radar to fail and deteriorate. By providing difficult-to-identify SAR interference, a novel and highly realistic threat model is offered for the research of radar system defense technology. Based on the same inventive concept, this invention also provides a SAR jamming device based on a phase-modulated corner reflector. Referring to Figure 6, which is a schematic diagram of the structure of a SAR jamming device based on a phase-modulated corner reflector provided in this invention, the SAR jamming device includes: an acquisition module 601 for acquiring echo signals; wherein the echo signals include a nonlinear phase modulation term introduced by a metasurface corner reflector; a processing module 602 for performing range processing on the echo signals to obtain a complex signal sequence; a motion compensation module 603 for performing motion compensation on the complex signal sequence and obtaining a mixed azimuth spectrum through Fourier transform; a filtering module 604 for performing azimuth-matched filtering based on the mixed azimuth spectrum to obtain a filtered signal; and a compensation module 605 for estimating the phase error of the filtered signal using the PGA algorithm and compensating the filtered signal using the estimated phase error to obtain a defocused image, thereby achieving SAR jamming.

[0055] In this embodiment of the invention, the acquired echo signal includes a nonlinear phase modulation term introduced by the metasurface corner reflector. This nonlinear phase modulation term can lead to the estimation of distorted phase errors in the subsequent PGA algorithm. When this phase error is used for whole-image compensation, not only the interference source itself, but also the target in the entire imaging area will become defocused, elevating the traditional point target deception interference to an overall suppression interference of the imaging area, thereby improving the interference effect and making it difficult to detect.

[0056] Optionally, the acquisition module 601 is specifically used to receive the real target echo signal from the radar; superimpose the interference echo signal generated by the metasurface corner reflector onto the real target echo signal to obtain the echo signal; the interference echo signal is generated based on a nonlinear phase modulation term.

[0057] Optionally, the processing module 602 is specifically used to perform range pulse compression and range migration correction on the echo signal to obtain a complex signal sequence.

[0058] Optionally, the nonlinear phase modulation term includes second-order or higher phase modulation terms.

[0059] Optionally, the nonlinear phase modulation term is a quadratic phase modulation term; the quadratic phase modulation term includes: ;in, This represents the second phase modulation term; Represents the imaginary unit; Indicates frequency modulation; Indicates direction and time.

[0060] Optionally, the echo signal includes: ;in, This refers to the echo signal; , Indicates the number of scattering sources; Indicates the scattering coefficient; Indicates the echo signal of a point target; , Indicates the number of echoes from a metasurface corner reflector; Indicates the first Scattering coefficient of a metasurface corner reflector; Indicates the first Ideal point target echo signal of a metasurface corner reflector; Indicates the first The instantaneous slant range of each scattering source; Indicates the first Instantaneous slant range of a metasurface corner reflector; symbol Indicates the parameter separator.

[0061] This invention also provides an electronic device, as shown in FIG7, including a processor 701, a communication interface 702, a memory 703, and a communication bus 704. The processor 701, the communication interface 702, and the memory 703 communicate with each other through the communication bus 704. The memory 703 is used to store computer programs. When the processor 701 executes the program stored in the memory 703, it implements the method steps of any of the above-mentioned SAR jamming methods based on phase modulation angle reflectors.

[0062] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used in the diagram, but this does not indicate that there is only one bus or one type of bus.

[0063] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0064] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0065] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be 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, or discrete hardware components.

[0066] The present invention also provides a computer-readable storage medium. A computer program is stored in the computer-readable storage medium, and when executed by a processor, the computer program implements the method steps of any of the above-described SAR jamming methods based on a phase-modulated angle reflector.

[0067] Optionally, the computer-readable storage medium may be non-volatile memory (NVM), such as at least one disk storage device.

[0068] Optionally, the aforementioned computer-readable storage medium may also be at least one storage device located remotely from the aforementioned processor.

[0069] In another embodiment of the present invention, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to perform the steps of any of the SAR jamming methods based on phase modulation angle reflectors described above.

[0070] It should be noted that the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0072] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings and the disclosure in carrying out the claimed invention. In the description of the invention, the word "comprising" does not exclude other components or steps, "a" or "an" does not exclude a plurality, and "a plurality" means two or more, unless otherwise explicitly specified. Furthermore, while different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce good results.

[0073] The method provided in this invention can be applied to electronic devices. Specifically, the electronic device can be a desktop computer, a portable computer, a smart mobile terminal, a server, etc. No limitation is made herein; any electronic device that can implement this invention falls within the protection scope of this invention.

[0074] For the embodiments of the device / electronic device / storage medium, since they are basically similar to the method embodiments, the description is relatively simple, and relevant parts can be referred to in the description of the method embodiments.

[0075] It should be noted that the device, electronic device and storage medium in the embodiments of the present invention are respectively the device, electronic device and storage medium for applying the above-mentioned SAR jamming method based on phase modulation angle reflector. Therefore, all embodiments of the above-mentioned SAR jamming method based on phase modulation angle reflector are applicable to the device, electronic device and storage medium, and can achieve the same or similar beneficial effects.

[0076] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A SAR jamming method based on a phase-modulated angle reflector, characterized in that, The SAR jamming method includes: acquiring an echo signal; wherein the echo signal includes a nonlinear phase modulation term introduced by a metasurface corner reflector; performing range processing on the echo signal to obtain a complex signal sequence; performing motion compensation on the complex signal sequence and obtaining a mixed azimuth spectrum through Fourier transform; performing azimuth matched filtering based on the mixed azimuth spectrum to obtain a filtered signal; using the PGA algorithm to estimate the phase error of the filtered signal, and using the estimated phase error to compensate for the filtered signal to obtain a defocused image, thereby achieving SAR jamming.

2. The SAR jamming method according to claim 1, characterized in that, Acquiring the echo signal includes: receiving the real target echo signal from the radar; superimposing the real target echo signal with an interference echo signal generated by a metasurface corner reflector to obtain the echo signal; the interference echo signal is generated based on a nonlinear phase modulation term.

3. The SAR jamming method according to claim 1, characterized in that, Range processing is performed on the echo signal to obtain a complex signal sequence, including: range pulse compression and range migration correction of the echo signal to obtain a complex signal sequence.

4. The SAR jamming method according to claim 1, characterized in that, The nonlinear phase modulation term includes phase modulation terms of second degree or higher.

5. The SAR jamming method according to claim 4, characterized in that, The nonlinear phase modulation term is a quadratic phase modulation term; The secondary phase modulation term includes: ;in, This represents the second phase modulation term; Represents the imaginary unit; Indicates frequency modulation; Indicates direction and time.

6. The SAR jamming method according to claim 1, characterized in that, The echo signal includes: ;in, This refers to the echo signal; ， Indicates the number of scattering sources; Indicates the scattering coefficient; Indicates the echo signal of a point target; ， Indicates the number of echoes from a metasurface corner reflector; Indicates the first Scattering coefficient of a metasurface corner reflector; Indicates the first Ideal point target echo signal of a metasurface corner reflector; Indicates the first The instantaneous slant range of each scattering source; Indicates the first Instantaneous slant range of a metasurface corner reflector; symbol Indicates parameter separator; Indicates direction and time.

7. A SAR jamming device based on a phase-modulated angle reflector, characterized in that, The SAR jamming device includes: an acquisition module for acquiring echo signals, wherein the echo signals include a nonlinear phase modulation term introduced by a metasurface corner reflector; a processing module for performing range processing on the echo signals to obtain a complex signal sequence; a motion compensation module for performing motion compensation on the complex signal sequence and obtaining a mixed azimuth spectrum through Fourier transform; a filtering module for performing azimuth-matched filtering based on the mixed azimuth spectrum to obtain a filtered signal; and a compensation module for estimating the phase error of the filtered signal using the PGA algorithm and compensating the filtered signal using the estimated phase error to obtain a defocused image, thereby achieving SAR jamming.

8. The SAR jamming device according to claim 7, characterized in that, The acquisition module is specifically used to receive the real target echo signal from the radar; to superimpose the interference echo signal generated by the metasurface corner reflector onto the real target echo signal to obtain the echo signal; the interference echo signal is generated based on a nonlinear phase modulation term.

9. An electronic device, characterized in that, The system includes a processor, a communication interface, a memory, and a communication bus. The processor, communication interface, and memory communicate with each other via the communication bus. The memory is used to store computer programs. When the processor executes the computer programs stored in the memory, it implements the SAR jamming method based on a phase modulation angle reflector as described in any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the SAR jamming method based on a phase-modulated angle reflector as described in any one of claims 1-6.

Images