SAR patch jamming methods, devices, and jammers based on aliasing point characteristics

Abstract

This invention relates to a SAR patch jamming method, apparatus, and jammer based on aliasing point characteristics. The method includes: Step S1, determining the position coordinates of the SAR patch interference in the SAR image under the SAR imaging coordinate system according to the spatial geometric relationship between the protected area, the jammer, and the SAR platform; Step S2, determining the position coordinates of the aliasing point in the SAR image according to the position coordinates of the patch in the SAR image and the constraint relationship between the aliasing point position and the patch position; Step S3, based on the positional relationship between the aliasing point, the jammer, and the SAR platform in the SAR image, using a method to generate aliasing point SAR echoes, forming SAR patch suppression interference at the protected area position in the SAR image. This invention achieves patch suppression protection for specific small areas of SAR imaging; furthermore, it has low power consumption, low computational load, flexible use, and reduces implementation difficulty.

Description

Technical Field

[0001] This invention belongs to the field of radar countermeasures technology, specifically relating to a SAR patch jamming method, device, and jammer based on aliasing point characteristics. Background Technology

[0002] Synthetic Aperture Radar (SAR) can observe the Earth around the clock and in all weather conditions, and can obtain clear two-dimensional images. In civilian applications, SAR can also be used for monitoring in areas such as meteorology, geological and mineral exploration, marine operations, water resources, agriculture and forestry, and flood disasters, all of which are of great significance.

[0003] Similarly, figuring out how to interfere with SAR equipment's imaging reconnaissance to achieve effective protection of specific areas is also of great significance.

[0004] Current techniques for SAR patch suppression include noise suppression jamming, noise convolutional modulation jamming, and stepped frequency shifting jamming. These jamming methods have the following problems in use:

[0005] (1) Noise suppression method has higher power because it does not utilize the two-dimensional coherence of SAR. When suppressing the same area, the power is tens of dB higher than that of the two-dimensional coherent method.

[0006] (2) The noise convolution method is computationally intensive, requiring the calculation of point targets comparable to the suppressed scene. For example, if the distance and orientation image interval is 1 meter, then to suppress a 200m×200 area, it is necessary to calculate 40,000 echo points.

[0007] (3) Stepped frequency shift interference can obtain partial matching gain in range and azimuth, and is relatively simple to implement, but it is not flexible enough in selecting the location of the suppression area. When the location of the protected area changes, stepped frequency shift interference is not easy to implement. Summary of the Invention

[0008] Based on the above analysis, the present invention aims to disclose a SAR patch jamming method, device and jammer based on the characteristics of aliasing points, which is used to solve the problem that it is difficult to simultaneously meet the multiple requirements of SAR patch suppression jamming power, computational load and suppression location that are flexible and changeable.

[0009] This invention discloses a SAR patch interference method based on aliasing point characteristics, comprising:

[0010] Step S1: Based on the spatial geometric relationship between the protected area, the jammer, and the SAR platform, determine the position coordinates of the SAR patch interference in the SAR image under the SAR imaging coordinate system;

[0011] Step S2: Determine the position coordinates of the aliasing point in the SAR image based on the position coordinates of the patch in the SAR image and the constraint relationship between the position of the aliasing point and the position of the patch.

[0012] Step S3: Based on the positional relationship between the aliasing points, jammers, and SAR platform in the SAR image, the SAR echo generation method is used to generate SAR patches in the protected area of ​​the SAR image to suppress interference.

[0013] Furthermore, step S2 specifically includes:

[0014] 1) Determine the proximity of the patch based on the center coordinates of the patch region in the SAR image and the phase center coordinates of the SAR antenna when passing through the center coordinates of the protected area;

[0015] 2) Based on the constraint relationship between the location of the aliasing point and the location of the patch, and the range requirement of the patch area, adjust the delay of the patch relative to the aliasing point and the proximity of the aliasing point so that the range of the patch formed by the interference meets the patch range requirement.

[0016] 3) Based on the proximity of the aliasing points and the delay of the patch relative to the aliasing points, the position coordinates of the aliasing points that meet the requirements of the patch area range in the SAR imaging coordinate system are obtained.

[0017] Furthermore, the constraint relationship between the location of the aliasing point and the location of the patch is as follows:

[0018]

[0019] Where R0' is the patch proximity, R0 is the aliasing point proximity, V is the SAR platform velocity, and t0 is the patch delay relative to the aliasing point, with the value of t ranging from...

[0020] Among them, the plaque is close to (0,0,H) represents the SAR antenna phase center coordinates when passing through the center coordinates of the protected area in the SAR imaging coordinate system; (X p (,0,0) represents the center coordinates of the patch protection area in the SAR imaging coordinate system.

[0021] Furthermore, in the requirements for the extent of the patch area, the patch slant distance width is:

[0022]

[0023] Where T is the time for synthesizing the pore size.

[0024] Furthermore, in the requirements for the extent of the patch area, the azimuth width of the patch is:

[0025]

[0026] Furthermore, the delay t0 of the patch relative to the aliasing point is adjusted to generate a patch that meets the requirements of the patch area range, and the proximity R0 of the aliasing point is determined.

[0027] Transform the lag t0 of the patch relative to the aliasing point and the proximity R0 of the aliasing point to the SAR imaging coordinate system to obtain the position coordinates (X) of the aliasing point. h Y h )for: Y h =Vt0.

[0028] Further, step S3 includes:

[0029] 1) Calculate the distance R from the aliasing point to the SAR antenna phase center based on the coordinates of the SAR antenna phase center, the coordinates of the aliasing point, and the coordinates of the jammer. sh The distance R from the jammer to the SAR sh ;

[0030] 2) After receiving the signal transmitted by the SAR, the jammer, according to R... sh and R sj The received SAR signal is delayed in distance and modulated in phase so that the signal relayed by the jammer arrives at the SAR receiver in the same way as the signal arriving at the SAR receiver from the aliasing point.

[0031] Furthermore, in the SAR imaging coordinate system, the coordinates of the SAR antenna phase center are (0, Vt, H), and the coordinates of the aliasing point are (X... h ,Y h The coordinates of the jammer are (X, 0), and the coordinates of the jammer are (X, 0). j ,Y j ,0);

[0032] The distance from the aliasing point to the SAR antenna phase center is calculated based on the coordinate relationship as follows:

[0033]

[0034] The distance from the jammer to the SAR is calculated based on the coordinate relationship:

[0035]

[0036] This invention also discloses a device for SAR patch interference based on aliasing point characteristics, comprising:

[0037] The patch location coordinate determination module is used to determine the location coordinates of SAR patch interference in the SAR image under the SAR imaging coordinate system based on the spatial geometric relationship between the protected area, the jammer, and the SAR platform.

[0038] The aliasing point location coordinate determination module is used to determine the location coordinates of the aliasing point in the SAR image based on the location coordinates of the patch in the SAR image and the constraint relationship between the location of the aliasing point and the location of the patch.

[0039] The interference signal generation module is used to generate SAR patch suppression interference in the protected area of ​​the SAR image by using the method of generating SAR echoes of aliasing points, jammers and SAR platform in the SAR image.

[0040] The present invention also discloses an jammer, which incorporates the SAR patch jamming device based on the aliasing point characteristics described above, to generate SAR patch jamming for SAR imaging reconnaissance of the protected area, thereby protecting the protected area.

[0041] This invention can achieve one of the following beneficial effects:

[0042] The SAR patch jamming method, apparatus, and jammer based on aliasing point characteristics of the present invention can achieve patch suppression and protection of specific small areas in SAR imaging; and...

[0043] It has low power consumption, low computational load, and flexible use. It can place patches at any location in the SAR image as needed to suppress and protect any area.

[0044] The implementation is simple, converting the patch suppression interference for SAR into SAR echo simulation for point targets, thus reducing the difficulty of implementation. Attached Figure Description

[0045] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0046] Figure 1 This is a flowchart of the SAR patch interference method based on aliasing point characteristics in an embodiment of the present invention;

[0047] Figure 2 This is a schematic diagram of the SAR imaging results without interference in an embodiment of the present invention;

[0048] Figure 3 This is a schematic diagram of the imaging result after adding patch interference to the imaging position of the protected area in an embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram illustrating the geometric relationship between SAR, jammer, and patch protection zone in an embodiment of the present invention;

[0050] Figure 5 This is a schematic diagram showing the slant distance correspondence between the main lobe inner point and the aliasing point in an embodiment of the present invention;

[0051] Figure 6 This is a schematic diagram of the geometric relationship between SAR, jammer, and aliasing point in an embodiment of the present invention;

[0052] Figure 7 This is a block diagram of a SAR patch interference device based on aliasing point characteristics in an embodiment of the present invention. Detailed Implementation

[0053] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0054] Example 1

[0055] One embodiment of the present invention discloses a SAR patch interference method based on aliasing point characteristics, such as... Figure 1 As shown, it includes:

[0056] Step S1: Based on the spatial geometric relationship between the protected area, the jammer, and the SAR platform, determine the position coordinates of the SAR patch interference in the SAR image under the SAR imaging coordinate system;

[0057] Step S2: Determine the position coordinates of the aliasing point in the SAR image based on the position coordinates of the patch in the SAR image and the constraint relationship between the position of the aliasing point and the position of the patch.

[0058] The aliasing point is a point that, in the SAR azimuth direction, is actually located outside the radar main lobe, but is imaged within the radar main lobe.

[0059] Step S3: Based on the positional relationship between the aliasing points, jammers, and SAR platform in the SAR image, the SAR echo generation method is used to generate SAR patches in the protected area of ​​the SAR image to suppress interference.

[0060] like Figure 2 The diagram shows the SAR imaging results without interference. Figure 3 This is a schematic diagram of the imaging result after adding patch interference to the imaging position of the protected area.

[0061] In step S1, based on the coordinates of the area to be protected, the coordinates of the jammer's location, and the motion state of the SAR platform, the spatial geometric relationship between the three is calculated, a SAR imaging coordinate system is established, and the location of the patch that can protect the area is determined in the SAR image.

[0062] In this embodiment, the center coordinates of the patch protection zone represent the location of the patch in the SAR image.

[0063] In the SAR imaging coordinate system, the X-axis represents the horizontal projection of the beam center illumination direction, the Y-axis is the SAR platform motion direction, and the Z-axis is vertically upward. A top view of these three axes is shown below. Figure 4 As shown. Since the protected area and the jammer's position are fixed, let the coordinates of the SAR antenna phase center when the SAR beam center illumination direction passes through the center coordinates of the protected area be (0,0,H). Then, based on the relative positional relationship of the three, the jammer's coordinates can be obtained as (X). j ,Y j The center coordinates of the patch protection area are (X, 0), p ,0,0).

[0064] Specifically, step S2 includes:

[0065] 1) Determine the proximity of the patch based on the center coordinates of the protected area in the SAR image and the phase center coordinates of the SAR antenna when passing through the center coordinates of the protected area;

[0066] Specifically, near-field plaques Where (0,0,H) represents the SAR antenna phase center coordinates when passing through the center coordinates of the protected area, (X p (,0,0) represents the center coordinates of the patch protection area.

[0067] 2) Based on the constraint relationship between the location of the aliasing point and the location of the patch, and the range requirement of the patch area, adjust the delay of the patch relative to the aliasing point and the proximity of the aliasing point so that the range of the patch formed by the interference meets the patch range requirement.

[0068] Specifically, the constraint relationship between the location of the aliasing point and the location of the patch is as follows:

[0069]

[0070] Where R0' is the patch proximity, R0 is the aliasing point proximity, V is the platform velocity, and t0 is the patch delay relative to the aliasing point. To ensure the determinism of the patch position, the value of time t ranges from [value missing].

[0071] Specifically, based on the actual situation, adjust the delay of the patch relative to the aliasing point, select an appropriate t0 value, and apply the constraint relationship between the aliasing point position and the patch position. The appropriate proximity value R0 of the aliasing point can be solved, thereby determining the location of the aliasing point. The position represented by the azimuth coordinate 0 of the aliasing point is different depending on the delay t0 of the patch relative to the aliasing point. This is equivalent to changing the position of the azimuth coordinate origin 0 along the azimuth direction according to the position of t0.

[0072] Specifically, the requirements for the extent of the patch area include the patch slant distance width and the patch azimuth width requirements.

[0073] More specifically, the methods for determining the required patch slant distance width include:

[0074] At the center of the plaque, the following conditions are met. The slant distance relationship between the in-matrix point and the aliasing point is shown in the diagram below. Figure 5 As shown, after distance migration correction, the points in the main lobe are corrected to straight lines along the azimuth direction, all within the same distance gate. After correction, the aliasing points are corrected to the same distance in the near direction (around time 0), so their distribution in the distance direction remains basically unchanged. This determines the width of the patch in the distance direction.

[0075] Preferably, in the requirement for the range of the patch area, the patch slant distance width can be determined according to formula... Calculate, where T is the time for synthesizing the aperture.

[0076] More specifically, the methods for determining the required azimuth width of patches include:

[0077] Synthetic Aperture Radar (SAR) moves in a synthetic aperture manner, generating a linear frequency modulated (LFM) signal in the azimuth direction. The LFM frequency is related to the platform's speed and proximity. Due to aliasing, during azimuth processing, aliased points do not receive an azimuth matching function corresponding to their proximity. Instead, an azimuth matching function with multiple range gates is used for compression. This azimuth mismatch causes azimuth broadening, and the degree of broadening determines the size of the aliased point patch in the azimuth direction.

[0078] Preferably, in the requirement for the extent of the patch area, the orientation and size of the patch can be determined according to formula... Perform the calculation.

[0079] 3) Based on the proximity of the aliasing points and the delay of the patch relative to the aliasing points, the position coordinates of the aliasing points that meet the patch range requirements in the SAR imaging coordinate system are obtained.

[0080] By adjusting the delay t0 of the patch relative to the aliasing point, a patch that meets the requirements can be generated, and the proximity R0 of the aliasing point can be determined to obtain the position coordinates (t0, R0) of the aliasing point.

[0081] Next, transform the coordinates of the aliasing point (t0, R0) into the SAR imaging coordinate system established in step S1. The X coordinate of the aliasing point is: The Y-coordinate of the aliasing point is Y h =Vt0.

[0082] Specifically, step S3 includes:

[0083] 1) Calculate the distance R from the aliasing point to the SAR antenna phase center based on the coordinates of the SAR antenna phase center, the coordinates of the aliasing point, and the coordinates of the jammer. sh The distance R from the jammer to the SAR sh ;

[0084] Specifically, in the SAR imaging coordinate system, the top view of the aliasing point, the jammer, and the SAR platform is as follows: Figure 6 As shown.

[0085] The phase center coordinates of the SAR antenna are (0, Vt, H), and the coordinates of the aliasing point are (X). h ,Y h The coordinates of the jammer are (X, 0), j ,Y j ,0);

[0086] The distance from the aliasing point to the SAR antenna phase center is calculated based on the coordinate relationship as follows:

[0087]

[0088] The distance from the jammer to the SAR is calculated based on the coordinate relationship:

[0089]

[0090] 2) After receiving the signal transmitted by the SAR, the jammer, according to R... sh and R sj The received SAR signal is delayed in distance and modulated in phase so that the signal relayed by the jammer arrives at the SAR receiver in the same way as the signal arriving at the SAR receiver from the aliasing point.

[0091] In summary, the SAR patch interference method based on aliasing point characteristics in the embodiments of the present invention can achieve patch suppression protection for specific small areas of SAR imaging; for example, covering an area the size of a truck, or a small area with a length and width of about 200 meters.

[0092] Furthermore, it has low power consumption, low computational load, and flexible use. It can place patches at any location in the SAR image to suppress and protect any area as needed. It is also simple to implement, converting the patch suppression interference of SAR into SAR echo simulation of point targets, which reduces the difficulty of implementation.

[0093] Example 2

[0094] This invention discloses a device for SAR patch interference based on aliasing point characteristics, such as... Figure 7 As shown, it includes:

[0095] The patch location coordinate determination module is used to determine the patch location coordinates of SAR patch interference in the SAR image under the SAR imaging coordinate system based on the spatial geometric relationship between the protected area, the jammer, and the SAR platform.

[0096] The aliasing point location coordinate determination module is used to determine the location coordinates of the aliasing point in the SAR image based on the location coordinates of the patch in the SAR image and the constraint relationship between the location of the aliasing point and the location of the patch.

[0097] The interference signal generation module is used to generate SAR patch suppression interference in the protected area of ​​the SAR image by generating SAR echoes of aliasing points, jammers and SAR platform in the SAR image based on the positional relationship of aliasing points, jammers and SAR platform in the SAR image.

[0098] The module for determining the coordinates of the aliasing point also includes:

[0099] The patch proximity calculation module is used to determine the patch proximity based on the center coordinates of the patch protection zone in the SAR image and the phase center coordinates of the SAR antenna when passing through the center coordinates of the protection zone.

[0100] The aliasing point proximity calculation module is used to adjust the delay of the patch relative to the aliasing point and the proximity of the aliasing point according to the constraint relationship between the position of the aliasing point and the position of the patch, as well as the range requirements of the patch area, so that the range of the patch formed by the interference meets the patch range requirements.

[0101] The aliasing point location coordinate calculation module is used to obtain the location coordinates of aliasing points in the SAR imaging coordinate system that meet the patch range requirements, based on the proximity of aliasing points and the delay of the patch relative to the aliasing points.

[0102] Specifically, near-field plaques Where (0,0,H) represents the SAR antenna phase center coordinates when passing through the center coordinates of the protected area, (X p (,0,0) represents the center coordinates of the patch protection area.

[0103] Specifically, the constraint relationship between the location of the aliasing point and the location of the patch is as follows:

[0104]

[0105] Where R0' is the patch proximity, R0 is the aliasing point proximity, V is the platform velocity, and t0 is the patch delay relative to the aliasing point. To ensure the determinism of the patch position, the value of time t ranges from [value missing].

[0106] Specifically, based on the actual situation, adjust the delay of the patch relative to the aliasing point, select an appropriate t0 value, and apply the constraint relationship between the aliasing point position and the patch position. The appropriate proximity value R0 of the aliasing point can be solved, thereby determining the location of the aliasing point. The position represented by the azimuth coordinate 0 of the aliasing point is different depending on the delay t0 of the patch relative to the aliasing point. This is equivalent to changing the position of the azimuth coordinate origin 0 along the azimuth direction according to the position of t0.

[0107] Specifically, the requirements for the extent of the patch area include the patch slant distance width and the patch azimuth width requirements.

[0108] More specifically, the methods for determining the required patch slant distance width include:

[0109] At the center of the plaque, the following conditions are met. The slant distance relationship between the in-matrix point and the aliasing point is shown in the diagram below. Figure 5 As shown, after distance migration correction, the points in the main lobe are corrected to straight lines along the azimuth direction, all within the same distance gate. After correction, the aliasing points are corrected to the same distance in the near direction (around time 0), so their distribution in the distance direction remains basically unchanged. This determines the width of the patch in the distance direction.

[0110] Preferably, in the requirement for the range of the patch area, the patch slant distance width can be determined according to formula... Calculate, where T is the time for synthesizing the aperture.

[0111] More specifically, the methods for determining the required azimuth width of patches include:

[0112] Synthetic Aperture Radar (SAR) moves in a synthetic aperture manner, generating a linear frequency modulated (LFM) signal in the azimuth direction. The LFM frequency is related to the platform's speed and proximity. Due to aliasing, during azimuth processing, aliased points do not receive an azimuth matching function corresponding to their proximity. Instead, an azimuth matching function with multiple range gates is used for compression. This azimuth mismatch causes azimuth broadening, and the degree of broadening determines the size of the aliased point patch in the azimuth direction.

[0113] Preferably, in the requirement for the extent of the patch area, the orientation and size of the patch can be determined according to formula... Perform the calculation.

[0114] By adjusting the delay t0 of the patch relative to the aliasing point, a patch that meets the requirements can be generated, and the proximity R0 of the aliasing point can be determined to obtain the position coordinates (t0, R0) of the aliasing point.

[0115] Next, transform the coordinates of the aliasing point (t0, R0) into the SAR imaging coordinate system established in step S1. The X coordinate of the aliasing point is: The Y-coordinate of the aliasing point is Y h =Vt0.

[0116] Other technical details and beneficial effects included in this embodiment are the same as those in Embodiment 1. Please refer to the specific content in Embodiment 1, and they will not be repeated here.

[0117] Example 3

[0118] This invention discloses an jammer that incorporates a SAR patch jamming device based on aliasing point characteristics as described in Embodiment 2. This device generates SAR patch jamming for SAR imaging reconnaissance of the protected area, thereby protecting the protected area.

[0119] The technical details and beneficial effects included in this embodiment are the same as those in Embodiment 1. Please refer to the specific content in Embodiment 1, and they will not be repeated here.

[0120] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A SAR patch interference method based on aliasing point characteristics, characterized in that, include: Step S1: Based on the spatial geometric relationship between the protected area, the jammer, and the SAR platform, determine the position coordinates of the SAR patch interference in the SAR image under the SAR imaging coordinate system; Step S2: Determine the position coordinates of the aliasing point in the SAR image based on the position coordinates of the patch in the SAR image and the constraint relationship between the position of the aliasing point and the position of the patch. Step S3: Based on the positional relationship between the aliasing points, jammers, and SAR platform in the SAR image, the SAR echo generation method is used to generate SAR patches in the protected area of ​​the SAR image to suppress interference.

2. The SAR patch interference method according to claim 1, characterized in that, Step S2 specifically includes: 1) Determine the proximity of the patch based on the center coordinates of the patch region in the SAR image and the phase center coordinates of the SAR antenna when passing through the center coordinates of the protected area; 2) Based on the constraint relationship between the location of the aliasing point and the location of the patch, and the range requirement of the patch area, adjust the delay of the patch relative to the aliasing point and the proximity of the aliasing point so that the range of the patch formed by the interference meets the patch range requirement. 3) Based on the proximity of the aliasing points and the delay of the patch relative to the aliasing points, the position coordinates of the aliasing points that meet the requirements of the patch area range in the SAR imaging coordinate system are obtained.

3. The SAR patch interference method according to claim 2, characterized in that, The constraint relationship between the location of the aliasing point and the location of the patch is as follows: Where R0' is the patch proximity, R0 is the aliasing point proximity, V is the SAR platform velocity, and t0 is the patch delay relative to the aliasing point, with the value of t ranging from... Among them, the plaque is close to (0,0,H) represents the SAR antenna phase center coordinates when passing through the center coordinates of the protected area in the SAR imaging coordinate system; (X p (,0,0) represents the center coordinates of the patch protection area in the SAR imaging coordinate system.

4. The SAR patch interference method according to claim 3, characterized in that, The required area for a patch region includes the patch slant distance width. Where T is the time for synthesizing the pore size.

5. The SAR patch interference method according to claim 3, characterized in that, The required area of ​​the patch includes the azimuth width of the patch:

6. The SAR patch interference method according to claim 3, characterized in that, Adjust the delay t0 of the patch relative to the aliasing point to generate a patch that meets the requirements of the patch area range, and determine the proximity R0 of the aliasing point; Transform the lag t0 of the patch relative to the aliasing point and the proximity R0 of the aliasing point to the SAR imaging coordinate system to obtain the position coordinates (X) of the aliasing point. h Y h )for: Y h =Vt0.

7. The SAR patch interference method according to claim 2, characterized in that, Step S3 includes: 1) Calculate the distance R from the aliasing point to the SAR antenna phase center based on the coordinates of the SAR antenna phase center, the coordinates of the aliasing point, and the coordinates of the jammer. sh The distance R from the jammer to the SAR sh ; 2) After receiving the signal transmitted by the SAR, the jammer, according to R... sh and R sj The received SAR signal is delayed in distance and modulated in phase so that the signal relayed by the jammer arrives at the SAR receiver in the same way as the signal arriving at the SAR receiver from the aliasing point.

8. The SAR patch interference method according to claim 7, characterized in that, In the SAR imaging coordinate system, the phase center coordinates of the SAR antenna are (0, Vt, H), and the coordinates of the aliasing point are (X, Vt, H). h ,Y h The coordinates of the jammer are (X, 0), and the coordinates of the jammer are (X, 0). j ,Y j ,0); The distance from the aliasing point to the SAR antenna phase center is calculated based on the coordinate relationship as follows: The distance from the jammer to the SAR is calculated based on the coordinate relationship:

9. A device for SAR patch interference based on aliasing point characteristics, characterized in that, include: The patch location coordinate determination module is used to determine the location coordinates of SAR patch interference in the SAR image under the SAR imaging coordinate system based on the spatial geometric relationship between the protected area, the jammer, and the SAR platform. The aliasing point location coordinate determination module is used to determine the location coordinates of the aliasing point in the SAR image based on the location coordinates of the patch in the SAR image and the constraint relationship between the location of the aliasing point and the location of the patch. The interference signal generation module is used to generate SAR patch suppression interference in the protected area of ​​the SAR image by using the method of generating SAR echoes of aliasing points, jammers and SAR platform in the SAR image.

10. A jamming device, characterized in that, The device for SAR patch interference based on aliasing point characteristics as described in claim 9 is built-in, which generates SAR patch interference for SAR imaging reconnaissance of the protected area, thereby protecting the protected area.

Images