A background deception jamming method based on electromagnetic scattering

Abstract

This invention discloses a background deception interference method based on electromagnetic scattering, comprising: determining a terrain region to be used as a background to interfere with a target area; sampling the terrain region to obtain the elevation information of the sampling points; dividing the terrain region into multiple sub-surfaces based on the sampling points after treating the surface region as a surface element, and calculating the electromagnetic scattering coefficient of each sub-surface element using the small slope approximation method and the elevation information; and obtaining the electromagnetic scattering coefficient σ of the terrain region based on the electromagnetic scattering coefficient of each sub-surface element. 假 According to the electromagnetic scattering coefficient σ of the terrain region 假 and the electromagnetic scattering coefficient σ of the target region 真 Electromagnetic scattering coefficient σ of generating deceptive interference scene 总 Electromagnetic scattering coefficient σ based on deceptive interference scenarios 总 After generating the jamming echo signal, the jamming echo signal is sent to the enemy SAR platform to form interference. This invention improves the real-time performance and the realism and diversity of the jamming background, and can be applied to deceptive jamming of SAR.

Description

Technical Field

[0001] This invention belongs to the field of radar technology, specifically relating to a background deception jamming method based on electromagnetic scattering. Background Technology

[0002] In modern electronic warfare, jamming of SAR (Synthetic Aperture Radar) systems is generally divided into suppression jamming and deception jamming. Suppression jamming involves a jammer transmitting a high-power signal to interfere with the opponent's SAR platform, causing the real target signal received by the opponent's SAR platform to be submerged in the jammed signal. Deception jamming refers to using a jammer to interfere with the characteristics of the echo signal, creating false targets in the imaging image. Realistic and sophisticated deception jamming scenarios can confuse the opponent's SAR, concealing or deceiving important targets or terrain. For our own SAR system, studying realistic and sophisticated jamming is beneficial for responding to similar jamming and preventing problems before they occur.

[0003] In existing technologies, background deception jamming of targets or terrain uses scattering wave jamming. The principle is to project the signal received from the opponent's SAR onto the jamming area, where it is scattered by ground objects to form a jamming wave that is then transmitted back to the opponent. However, compared to direct jamming, this method involves an additional process from the jammer to the jamming ground object and back to the radar, resulting in a longer time delay. Furthermore, it must meet range abrupt change criteria and focusing depth criteria, leading to higher jamming complexity. Jamming relay is mostly in the neighborhood, resulting in a simpler jamming background. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this invention provides a background deception interference method based on electromagnetic scattering. The technical problem to be solved by this invention is achieved through the following technical solution:

[0005] This invention provides a background deception interference method based on electromagnetic scattering, comprising:

[0006] Identify the terrain areas to be used as background to interfere with the target area;

[0007] The terrain area is sampled to obtain the elevation information of the sampling points;

[0008] After taking the terrain region as a surface element, the surface element is divided into multiple sub-surface elements based on the sampling points, and the electromagnetic scattering coefficient of each sub-surface element is calculated using the small slope approximation method and the elevation information.

[0009] Based on the electromagnetic scattering coefficient of each sub-surface element, the electromagnetic scattering coefficient σ of the terrain region is obtained. 假 ;

[0010] According to the electromagnetic scattering coefficient σ of the terrain region 假 and the electromagnetic scattering coefficient σ of the target region 真 Electromagnetic scattering coefficient σ of generating deceptive interference scene 总 ;

[0011] Electromagnetic scattering coefficient σ based on deceptive interference scenarios 总 After generating the interference echo signal, the interference echo signal is sent to the enemy SAR platform to create interference.

[0012] In one embodiment of the present invention, the step of sampling the terrain area to obtain the elevation information of the sampling points includes:

[0013] The terrain area is sampled at a preset sampling interval to obtain digital elevation data of the sampling point (a,b) in row a and column b; the preset sampling interval is λ / 8, where λ represents the wavelength of the synthetic aperture radar.

[0014] Based on the digital elevation data of sampling point (a,b), obtain the elevation information Z of sampling point (a,b). ab And store it as a matrix.

[0015] In one embodiment of the present invention, the steps of taking the terrain region as a surface element, dividing the surface element into multiple sub-surface elements based on the sampling points, and calculating the electromagnetic scattering coefficient of each sub-surface element using the small slope approximation method and the elevation information include:

[0016] The terrain region is taken as a surface element, and the surface element is divided into multiple sub-surface elements based on the sampling points, wherein the side length of the sub-surface element is 8λ.

[0017] For each sub-surface element, a local coordinate system is established with the center of the sub-surface element as the reference point o, and the height of each sampling point in the sub-surface element relative to the reference point o is determined based on the elevation information of each sampling point in the sub-surface element.

[0018] The electromagnetic scattering coefficient of each sub-surface element is calculated using the small slope approximation method based on the height of each sampling point in the sub-surface element relative to the reference point o.

[0019] In one embodiment of the present invention, the z-axis of the local coordinate system is perpendicular to the sub-surface element, the xoy plane is perpendicular to the z-axis, and the height of the sampling point (a,b) in the sub-surface element relative to the reference point o is Z. ab -Z o .

[0020] In one embodiment of the present invention, the step of calculating the electromagnetic scattering coefficient of each sub-surface element using the small slope approximation method based on the height of each sampling point in the sub-surface element relative to the reference point o includes:

[0021] The amplitude of the sub-element (m,n) is calculated based on the height of each sampling point in the sub-element relative to the reference point o:

[0022]

[0023] In the formula, Let k0 represent the first-order coefficient matrix of the sub-element (m,n) in the m-th row and n-th column, k0 represent the horizontal component of the incident wave, k represent the horizontal component of the scattered wave, j represent the imaginary unit, and q represent the first-order coefficient matrix of the sub-element (m,n). mn0 =k mni cosθ mni q mn =k mni cosθ mns k mni θ represents the incident wave number of the sub-element (m,n). i θ represents the angle of incidence of the sub-element (m,n). mns Let (r, h(r)) represent the scattering angle of the sub-surface element (m, n), and let (r, h(r)) represent the coordinates of the sub-surface element (m, n) in the local coordinate system.

[0024] Calculate the electromagnetic scattering coefficient of the sub-element (m,n) based on its amplitude:

[0025]

[0026] In the formula, * indicates taking the conjugate.

[0027] In one embodiment of the present invention, the electromagnetic scattering coefficient σ of the terrain region 假 for:

[0028]

[0029] In the formula, M and N represent the number of rows and columns of the sub-face element, respectively.

[0030] In one embodiment of the present invention, based on the electromagnetic scattering coefficient σ of the terrain region... 假 and the electromagnetic scattering coefficient σ of the target region 真 Electromagnetic scattering coefficient σ of generating deceptive interference scene 总 The steps include:

[0031] Based on the electromagnetic scattering coefficient σ of the terrain region 假 and the electromagnetic scattering coefficient σ of the target region 真 Calculate the scattering increment:

[0032] σ 增 (m,n)=σ 真 (m,n)-σ 假 (m,n);

[0033] Based on scattering increment σ 增 Electromagnetic scattering coefficients for generating deceptive interference scenarios:

[0034] σ 总 (m,n)=σ 真 (m,n)+σ 增 (m,n).

[0035] In one embodiment of the present invention, the electromagnetic scattering coefficient σ based on the deceptive interference scenario... 总 The step of generating an interference echo signal and then sending the interference echo signal to an enemy SAR platform to create interference includes:

[0036] Electromagnetic scattering coefficient σ in a deceptive interference scenario based on sub-surface elements (m,n) 总 This generates interference echo signals.

[0037]

[0038] In the formula, t represents time, and τ mn k represents the time delay from the synthetic aperture radar signal to the sub-element (m,n). mn (a) represents the phase of the orientation of the sub-element (m,n).

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] This invention provides a background deception jamming method based on electromagnetic scattering, which belongs to direct-emission jamming. Existing background deception jamming methods targeting targets or terrain use scattered wave jamming, which works by projecting the received signal from the target's SAR onto the jamming area. After scattering by ground objects, the resulting jamming wave is transmitted back to the target. Compared to this invention, the aforementioned methods involve an additional process from the jammer to the jamming ground object and back to the radar. Therefore, this invention avoids the time delay of relaying to other areas, improving the real-time performance of the jamming. Furthermore, by introducing electromagnetic scattering, this invention accurately simulates the electromagnetic scattering characteristics of the terrain to be used as the jamming background and applies it to the jamming of characteristic targets, which helps improve the realism of the jamming background and achieves a better jamming effect.

[0041] Furthermore, traditional scattering interference forwards to the neighborhood, and the terrain scene near the target usually changes in a single way. This application, however, can calculate the scattering characteristics of various terrains and interfere with the same target area with multiple different terrains, which is more diverse.

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0043] Figure 1This is a flowchart of a background deception interference method based on electromagnetic scattering provided in an embodiment of the present invention;

[0044] Figure 2a This is a SAR image of desert terrain provided in an embodiment of the present invention;

[0045] Figure 2b This is another SAR image of desert terrain provided in this embodiment of the invention;

[0046] Figure 3a This is a SAR image of mountainous terrain provided in an embodiment of the present invention;

[0047] Figure 3b This is another SAR image of mountainous terrain provided in an embodiment of the present invention;

[0048] Figure 4a This is a SAR image of grassland terrain provided in an embodiment of the present invention;

[0049] Figure 4b This is another SAR image of grassland terrain provided in this embodiment of the invention;

[0050] Figure 5a This is a SAR image of an airport provided in an embodiment of the present invention;

[0051] Figure 5b This is another SAR image of the airport provided in this embodiment of the invention;

[0052] Figure 6a This is a SAR image of farmland provided in an embodiment of the present invention;

[0053] Figure 6b This is another SAR image of farmland provided in an embodiment of the present invention;

[0054] Figure 7a This is a SAR image of an airport that uses desert terrain as a background, as provided in an embodiment of the present invention.

[0055] Figure 7b This is a SAR image of an airport that uses grassland terrain as a background, as provided in an embodiment of the present invention.

[0056] Figure 8a This is a SAR image of farmland that uses desert terrain as a background, as provided in an embodiment of the present invention.

[0057] Figure 8b This is a SAR image of farmland that uses grassland terrain as a background, provided in an embodiment of the present invention. Detailed Implementation

[0058] 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.

[0059] Figure 1 This is a flowchart of a background deception interference method based on electromagnetic scattering provided in an embodiment of the present invention. Figure 1 As shown, this embodiment of the invention provides a background deception interference method based on electromagnetic scattering, including:

[0060] S1. Determine the terrain area to be used as a background to interfere with the target area;

[0061] S2. Sample the terrain area to obtain the elevation information of the sampling points;

[0062] S3. After taking the terrain region as a surface element, the surface element is divided into multiple sub-surface elements based on the sampling points, and the electromagnetic scattering coefficient of each sub-surface element is calculated using the small slope approximation method and elevation information.

[0063] S4. Based on the electromagnetic scattering coefficient of each sub-surface element, obtain the electromagnetic scattering coefficient σ of the terrain region. 假 ;

[0064] S5. Based on the electromagnetic scattering coefficient σ of the terrain region 假 and the electromagnetic scattering coefficient σ of the target region 真 Electromagnetic scattering coefficient σ of generating deceptive interference scene 总 ;

[0065] S6. Electromagnetic scattering coefficient σ based on deceptive interference scenarios 总 After generating the interference echo signal, the interference echo signal is sent to the enemy's SAR platform to create interference.

[0066] It should be noted that when selecting a real terrain area as a background to interfere with the target area, the environment in which the target area is located should be taken into account. For example, when the target area is an airport, since airports are usually located in grasslands and deserts, the selected terrain area can be grassland or desert.

[0067] Step S2 above, which involves sampling the terrain area to obtain the elevation information of the sampling points, includes:

[0068] S201. The terrain area is sampled at a preset sampling interval to obtain the digital elevation data of the sampling point (a,b) in the a-th row and b-th column; the preset sampling interval is λ / 8, where λ represents the wavelength of the synthetic aperture radar.

[0069] S202. Based on the digital elevation data of sampling point (a,b), obtain the elevation information Z of sampling point (a,b). ab And store it as a matrix.

[0070] Digital elevation data files typically include two types: SRTM1 and SRTM3, with accuracies of 30m and 90m respectively. This embodiment uses the higher-accuracy SRTM1 data and stores the extracted digital elevation (DEM) data of the terrain area as a matrix, which can be represented as follows: Where, p ab p represents the digital elevation data of sampling point (a,b). ab = (X,Y,Z). Since only the height information Z of the sampling point is needed when calculating the electromagnetic scattering coefficient, the elevation information of the sampling point in the DEM data can be represented as...

[0071] In addition, since the small slope approximation method is used when calculating the electromagnetic scattering coefficient of the sub-surface element, this method requires the sampling interval Δx between two sampling points to be ≤λ / 8. Therefore, in step S201, sampling is performed according to the preset sampling interval λ / 8.

[0072] Step S3, which involves dividing the terrain region into multiple sub-surfaces based on sampling points after using the surface area as a surface element, and calculating the electromagnetic scattering coefficient of each sub-surface element using the small slope approximation method and elevation information, includes:

[0073] S301. Take the terrain region as a surface element, and divide the surface element into multiple sub-surface elements based on the sampling points. The side length of each sub-surface element is 8λ.

[0074] S302. For each sub-surface element, establish a local coordinate system with the center of the sub-surface element as the reference point o, and determine the height of each sampling point in the sub-surface element relative to the reference point o based on the elevation information of each sampling point in the sub-surface element.

[0075] S303. Based on the height of each sampling point in the sub-surface element relative to the reference point o, calculate the electromagnetic scattering coefficient of each sub-surface element using the small slope approximation method.

[0076] Specifically, in this embodiment, the terrain region is treated as a surface element, and the entire surface element is considered as countless scatterers. Therefore, the entire terrain region can be divided into multiple sub-surface elements. Optionally, each sub-surface element has a side length of 8λ, resulting in 64 elevation information points for each sub-surface element. The elevation information set of the entire terrain region can then be represented as follows: Among them, S mn This represents the sub-face element in the m-th row and n-th column.

[0077] In steps S302-S303, each sub-surface element is treated as an independent scattering body. Then, a local coordinate system is established for each sub-surface element. For example, a local coordinate system is established with the center of the sub-surface element as the reference point o. The z-axis of the local coordinate system is perpendicular to the sub-surface element, and the xoy plane is perpendicular to the z-axis. The height of the sampling point (a,b) in the sub-surface element relative to the reference point o is Z. ab -Z o

[0078] Furthermore, the steps for calculating the electromagnetic scattering coefficient of each sub-element using the small slope approximation method based on the height of each sampling point in the sub-element relative to the reference point o include:

[0079] S3031. Calculate the amplitude of sub-element (m,n) based on the height of each sampling point in the sub-element relative to the reference point o:

[0080]

[0081] In the formula, Let k0 represent the first-order coefficient matrix of the sub-element (m,n) in the m-th row and n-th column, k0 represent the horizontal component of the incident wave, k represent the horizontal component of the scattered wave, j represent the imaginary unit, and q represent the first-order coefficient matrix of the sub-element (m,n). mn0 =k mni cosθ mni q mn =k mni cosθ mns k mni θ represents the incident wave number of the sub-element (m,n). i θ represents the angle of incidence of the sub-element (m,n). mns Let (r, h(r)) represent the scattering angle of the sub-surface element (m, n), and let (r, h(r)) represent the coordinates of the sub-surface element (m, n) in the local coordinate system.

[0082] Based on the different polarization conditions when synthetic aperture radar transmits electromagnetic waves, the first-order coefficient matrix of the sub-surface element (m,n) is... Specifically, it can be expressed as:

[0083]

[0084] in, ε represents the unit normal vector of the horizontal plane of sub-surface element (m,n). r The complex permittivity of the terrain region is represented by ω, where ω is the angular frequency. This represents a first-order coefficient matrix indicating that both the transmitted and received signals are vertically polarized. This represents a first-order coefficient matrix indicating that the transmitted signal is vertically polarized and the received signal is horizontally polarized. This represents the first-order coefficient matrix indicating that the transmitted signal is horizontally polarized and the received signal is vertically polarized. This represents a first-order coefficient matrix indicating that both the transmitted and received signals are horizontally polarized.

[0085] q1, q2, q 01 and q 02 The following formula can be used for calculation:

[0086]

[0087]

[0088] c is the speed of light.

[0089] S3032. Calculate the electromagnetic scattering coefficient of the sub-element (m,n) based on its amplitude:

[0090]

[0091] In the formula, * indicates taking the conjugate.

[0092] In this embodiment, the electromagnetic scattering coefficient σ of the terrain region 假 for:

[0093]

[0094] In the formula, M and N represent the number of rows and columns of the sub-face element, respectively.

[0095] Optionally, in step S5, based on the electromagnetic scattering coefficient σ of the terrain region... 假 and the electromagnetic scattering coefficient σ of the target region 真 Electromagnetic scattering coefficient σ of generating deceptive interference scene 总 The steps include:

[0096] S501, Electromagnetic scattering coefficient σ based on terrain region 假 and the electromagnetic scattering coefficient σ of the target region 真 Calculate the scattering increment:

[0097] σ 增 (m,n)=σ 真 (m,n)-σ 假 (m,n);

[0098] S502, Based on scattering increment σ 增 Electromagnetic scattering coefficients for generating deceptive interference scenarios:

[0099] σ 总 (m,n)=σ 真 (m,n)+σ 增 (m,n).

[0100] In step S6, the electromagnetic scattering coefficient σ based on the deceptive interference scenario is...总 The steps for generating an interference echo signal and then sending it to the enemy SAR platform to create interference include:

[0101] Electromagnetic scattering coefficient σ in a deceptive interference scenario based on sub-surface elements (m,n) 总 This generates interference echo signals.

[0102]

[0103] In the formula, t represents time, and τ mn k represents the time delay from the synthetic aperture radar signal to the sub-element (m,n). mn (a) represents the phase of the orientation of the sub-element (m,n).

[0104] The background deception interference method based on electromagnetic scattering provided by this invention will be further illustrated below through simulation experiments.

[0105] The scattering coefficients of desert, grassland, and mountain terrains were calculated using the small slope approximation method. First, imaging was performed using the scattering coefficients of these three terrain types. The parameters of the synthetic aperture radar are shown in Table 1.

[0106] Table 1

[0107] carrier frequency 3GHz bandwidth 300MHz Pulse width 1.5us resolution 1m*1m Platform flight speed 100m / s

[0108] Figures 2a-2b This is a SAR image of desert terrain provided in an embodiment of the present invention. Figures 3a-3b This is a SAR image of mountainous terrain provided in an embodiment of the present invention. Figures 4a-4b This is a SAR image of grassland terrain provided in an embodiment of the present invention. Figures 5a-5b This is a SAR image of an airport provided in an embodiment of the present invention. Figures 6a-6b This is a SAR image of farmland provided in an embodiment of the present invention. The target area is an airport and farmland. Considering that the background of the airport and farmland is not suitable for mountainous terrain, desert and grassland terrain are used to interfere with the background of the airport and farmland.

[0109] Figure 7a This is a SAR image of an airport that uses desert terrain as a background, provided in an embodiment of the present invention. Figure 7b This is a SAR image of an airport that uses grassland terrain as background interference, provided in an embodiment of the present invention. Figure 8a This is a SAR image provided by an embodiment of the present invention that uses desert terrain as a background to interfere with farmland. Figure 8b This is a SAR image of farmland interfering with grassland terrain, provided in an embodiment of the present invention. Please refer to... Figure 5a , 5bFigures 7a and 7b, based on Figure 5, utilize desert and grassland terrain respectively to create background interference. From the image domain perspective, the interference effect is good. Furthermore, as... Figure 6a , 6b and Figure 8a , 8b As shown, the interference creates background interference on the farmland, causing it to appear on different terrain backgrounds, and the interference effect is good when observed from the image domain.

[0110] As can be seen from the above embodiments, the beneficial effects of the present invention are as follows:

[0111] This invention provides a background deception jamming method based on electromagnetic scattering, which belongs to direct-emission jamming. Existing background deception jamming methods targeting targets or terrain use scattered wave jamming, which works by projecting the received signal from the target's SAR onto the jamming area. After scattering by ground objects, the resulting jamming wave is transmitted back to the target. Compared to this invention, the aforementioned methods involve an additional process from the jammer to the jamming ground object and back to the radar. Therefore, this invention avoids the time delay of relaying to other areas, improving the real-time performance of the jamming. Furthermore, by introducing electromagnetic scattering, this invention accurately simulates the electromagnetic scattering characteristics of the terrain to be used as the jamming background and applies it to the jamming of characteristic targets, which helps improve the realism of the jamming background and achieves a better jamming effect.

[0112] Furthermore, traditional scattering interference forwards to the neighborhood, and the terrain scene near the target usually changes in a single way. This application, however, can calculate the scattering characteristics of various terrains and interfere with the same target area with multiple different terrains, which is more diverse.

[0113] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0114] The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples" in the description refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which 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. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0115] Although this application has been described herein in conjunction with various embodiments, other variations of the disclosed embodiments can be understood and implemented by those skilled in the art in carrying out the claimed application by reviewing the accompanying drawings, the disclosure, and the appended claims.

[0116] 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 background deception interference method based on electromagnetic scattering, characterized in that, include: Identify the terrain areas to be used as background to interfere with the target area; The terrain area is sampled to obtain the elevation information of the sampling points; After taking the terrain region as a surface element, the surface element is divided into multiple sub-surface elements based on the sampling points, and the electromagnetic scattering coefficient of each sub-surface element is calculated using the small slope approximation method and the elevation information. The electromagnetic scattering coefficient of the terrain region is obtained based on the electromagnetic scattering coefficient of each sub-surface element. ; Based on the electromagnetic scattering coefficient of the terrain region and the electromagnetic scattering coefficient of the target region Electromagnetic scattering coefficients for generating deceptive interference scenarios ; Electromagnetic scattering coefficient based on deceptive interference scenarios After generating the interference echo signal, the interference echo signal is sent to the enemy SAR platform to create interference; The steps of taking the terrain region as a surface element, dividing the surface element into multiple sub-surface elements based on the sampling points, and calculating the electromagnetic scattering coefficient of each sub-surface element using the small slope approximation method and the elevation information include: The terrain region is used as a surface element, and based on the sampling points, this surface element is divided into multiple sub-surface elements, wherein the side length of each sub-surface element is... , Indicates the wavelength of the synthetic aperture radar; For each sub-element, the center of the sub-element is used as the reference point. A local coordinate system is established, and the relative reference point of each sampling point in the sub-element is determined based on the elevation information of each sampling point in the sub-element. Height; Based on the relative reference point of each sampling point in the sub-element The electromagnetic scattering coefficient of each sub-surface element is calculated using the small slope approximation method based on the height of the sub-surface element.

2. The background deception interference method based on electromagnetic scattering according to claim 1, characterized in that, The step of sampling the terrain area to obtain the elevation information of the sampling points includes: The terrain area is sampled at a preset sampling interval to obtain the first... line, number Sampling points of the column Digital elevation data; the preset sampling interval is , Indicates the wavelength of the synthetic aperture radar; Based on sampling points Digital elevation data, obtaining sampling points Elevation information And store it as a matrix.

3. The background deception interference method based on electromagnetic scattering according to claim 2, characterized in that, The local coordinate system z The axis is perpendicular to the sub-surface element. xoy plane and z The axis is perpendicular, and the sampling points in the sub-surface element are... relative reference point The height is .

4. The background deception interference method based on electromagnetic scattering according to claim 3, characterized in that, Based on the relative reference point of each sampling point in the sub-element The steps for calculating the electromagnetic scattering coefficient of each sub-surface element using the small slope approximation method, based on the height of the sub-surface element, include: Based on the relative reference point of each sampling point in the sub-element Height, calculate sub-face element Amplitude: In the formula, Indicates the first line, number Sub-face elements of the column The first-order coefficient matrix, Represents the horizontal component of the incident wave. Represents the horizontal component of the scattered wave. Represents the imaginary unit. , , Sub-face element The incident wave number, Sub-face element The angle of incidence, Sub-face element The scattering angle, Sub-face element Coordinates in the local coordinate system; According to sub-face element The electromagnetic scattering coefficient of the sub-surface element is calculated based on the amplitude: ； In the formula, This indicates taking the conjugate.

5. The background deception interference method based on electromagnetic scattering according to claim 4, characterized in that, Electromagnetic scattering coefficient of the terrain region for: ； In the formula, , These represent the number of rows and columns of the sub-face element, respectively.

6. The background deception interference method based on electromagnetic scattering according to claim 1, characterized in that, Based on the electromagnetic scattering coefficient of the terrain region and the electromagnetic scattering coefficient of the target region Electromagnetic scattering coefficients for generating deceptive interference scenarios The steps include: Based on the electromagnetic scattering coefficient of the terrain region and the electromagnetic scattering coefficient of the target region Calculate the scattering increment: ； In the formula, Indicates the first line, number Sub-face elements of a column; Based on scattering increment Electromagnetic scattering coefficients for generating deceptive interference scenarios: 。 7. The background deception interference method based on electromagnetic scattering according to claim 6, characterized in that, Electromagnetic scattering coefficient based on deceptive interference scenarios The step of generating an interference echo signal and then sending the interference echo signal to an enemy SAR platform to create interference includes: Based on sub-face element Electromagnetic scattering coefficient of deceptive interference scenarios This generates interference echo signals. ； In the formula, Indicates time, This indicates the signal to sub-surface element of synthetic aperture radar. The time delay, Sub-face element Azimuth phase, , These represent the number of rows and columns of the sub-face element, respectively.

Images