Quasi-polyhedron omnidirectional radar wave scattering regulation and control structure and construction method

Abstract

The invention relates to a quasi-polyhedron omnidirectional radar wave scattering regulation and control structure and a construction method, belongs to the technical field of radar wave scattering regulation and control structures, and solves the problem that in the prior art, scattering sectional area and angle domain characteristics are difficult to balance. The construction method comprises the steps that an octahedron corner reflector frame is established, four corner reflectors are arranged on each surface of an octahedron, each surface is translated in the direction away from the center point, three non-center corner reflectors in each surface rotate by an angle alpha around the edge of the center corner reflector in the center direction of the octahedron, and the angle alpha is larger than the angle alpha. The edges of the eight surfaces are interconnected. According to the invention, the quasi-32-surface shape is adopted, the right-angle three-surface corner reflectors are arranged on the 32 opening surfaces of the 32-surface body, the space angle domain stable distribution characteristic and the radar scattering cross section intensity of the corner reflectors are well balanced, the backward / single-station radar scattering cross section of the corner reflector combination is uniformly distributed in the angle domain, and the radar scattering cross section intensity is improved. The structure is an ideal radar wave scattering structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar wave scattering regulation structure, and particularly relates to a quasi-polyhedral omnidirectional radar wave scattering regulation structure and a construction method. BACKGROUND

[0002] Compared with other types of detection means, the radar wave detection means has the advantages of all-weather, all-time work and long detection distance, and thus becomes an effective and reliable environment and target sensing means.

[0003] A radar target is a general term for a structure for simulating the radar scattering characteristics of a target, and the radar target is divided into two main structural forms of a passive target and an active target.

[0004] The passive target usually utilizes the strong scattering effect of a metal surface on radar waves, adopts structural styles of a plane, a dihedral angle, a trihedral angle and a curved surface, forms a large radar scattering cross section, and thus overcomes the influence of noise in a practical environment.

[0005] In terms of structural style selection, a right-angle trihedral angle utilizes the principle of multipath scattering and can produce strong radar wave scattering in a specific angle domain. A metal sphere has a smooth radar scattering angle domain distribution characteristic, but the peak value of its scattering cross section is smaller than that of the right-angle trihedral angle. Therefore, the right-angle trihedral angle and the sphere become two basic structural styles of the passive radar target.

[0006] Since the angle range covered by a single right-angle trihedral angle is limited, a practical structure usually adopts a form of combination of multiple trihedral angles, such as an octahedral angle reflector and an icosahedral angle reflector. The right-angle trihedral angle is arranged on each port surface, so that the angle reflector covers a large angle domain range.

[0007] Although the icosahedral angle reflector has entered engineering application, its angle domain range is still not ideal, and the angle reflector still has obvious fluctuations in the angle domain, which easily causes problems such as tracking loss in training. Therefore, how to balance the number of angle reflector combinations, the overall scattering value of the angle reflector and the manufacturing complexity is still one of the main problems in the development field of the angle reflector.

[0008] The right-angled trihedral structure is a widely used structural style in the field of radar corner reflectors. Its simple structure allows for a large radar cross-section, thus overcoming the influence of environmental clutter and forming a strong radar-scattering structure that is easily detected and identified. However, the radar cross-section of a right-angled trihedral reaches its maximum value at the geometric center of the aperture. As the observation angle deviates from the geometric center angle, the radar cross-section gradually decreases, easily leading to target loss during radar detection, identification, and tracking. To overcome this problem and achieve a corner reflector assembly structure with stable angular domain characteristics, theoretically, as many right-angled trihedral reflectors as possible should be arranged on the aperture. However, while keeping the outer contour dimensions of the corner reflector assembly constant, increasing the number of right-angled trihedral reflector units means a smaller edge / aperture size and a smaller scattering cross-section characteristic value, which is detrimental to radar calibration and detection applications. Summary of the Invention

[0009] Based on the above analysis, the embodiments of the present invention aim to provide a quasi-polyhedral omnidirectional radar wave scattering control structure and construction method to solve the problem of difficulty in balancing the scattering cross-section and angular domain characteristics, and to better balance the number of corner reflector units, the size of corner reflector units, and the space utilization rate of omnidirectional corner reflectors.

[0010] On the one hand, the present invention provides a method for constructing a quasi-polyhedral omnidirectional radar wave scattering control structure, comprising the following steps:

[0011] The first step is to construct an octahedral corner reflector frame, which contains eight surfaces, each of which is an equilateral triangle with a side length of a. The three vertices of the octahedron are defined as the X, Y, and Z axes, respectively.

[0012] The second step involves decomposing each surface of the octahedral corner reflector frame into four small equilateral triangles by connecting the midpoints of the three sides of each surface. A corner reflector is positioned at the location of each small equilateral triangle. Each corner reflector comprises three mutually perpendicular plane mirrors, each plane mirror being an isosceles right triangle. Each side of one of the small equilateral triangles forms the base of the isosceles right triangle. The small equilateral triangles constitute the opening of the corner reflector. The side length of the opening of the corner reflector is a / 2, and the edge length of the corner reflector is...

[0013] The third step is to treat the four corner reflectors on each surface as a whole and move them by a distance g along the X, Y, and Z axes in a direction away from the center point of the octahedron.

[0014] The fourth step involves rotating the three non-central corner reflectors on each surface around the edge of the central corner reflector toward the center of the octahedron by an angle α, so that the line connecting the vertex of each corner reflector and the center of the facet points to the center point of the octahedron; thus connecting the edges of the eight surfaces to each other to form the quasi-polyhedral omnidirectional radar wave scattering control structure.

[0015] Furthermore, the value of a ranges from 0.01 to 50 meters.

[0016] Furthermore, the value of g ranges from 0.01 meters to 10 meters.

[0017] Furthermore, in the fourth step, after the three non-central corner reflectors on each surface have been rotated, the structure that extends beyond the quadrant in which the surface is located is cut off.

[0018] Furthermore, the fifth step involves calculating the radar cross-section and the angular domain distribution curve of the quasi-polyhedral omnidirectional radar wave scattering control structure using electromagnetic calculation software, adjusting parameters a, g, and α based on the calculation results, and iterating multiple times to obtain the final structure.

[0019] Furthermore, in the fifth step, if the calculated radar cross section is smaller than the expected value, then the length 'a' is increased, and steps one through five are repeated; if the calculated radar cross section is larger than the expected value, then the length 'a' is decreased, and steps one through five are repeated; if the calculated radar cross section is equal to the expected value, then the final value of 'a' is obtained.

[0020] Furthermore, in the fifth step, the radar cross section angle domain distribution curve is estimated multiple times. If the average value of the curve is less than the preset value, then g is increased and the third to fifth steps are repeated; if the average value of the curve is greater than the preset value, then g is decreased and the third to fifth steps are repeated; if the average value of the curve is equal to the preset value, then g is the final value at this time; the value of α gradually increases from 0, and the variance of the radar cross section angle domain distribution curve is calculated at the same time. When the variance reaches the minimum value, the corresponding α is the final value.

[0021] Furthermore, the plane mirror is made of a flat metal plate.

[0022] Furthermore, the corner reflector is formed by welding, bending, or bonding the metal plate.

[0023] On the other hand, the present invention provides a quasi-polyhedral omnidirectional radar wave scattering control structure, which is obtained according to the construction method described above.

[0024] Compared with existing technologies, this invention employs a combination of corner reflectors with a quasi-dodecahedral shape, arranging right-angled trihedral corner reflectors on the thirty-two faces of the dodecahedron. This arrangement effectively balances the spatial angular distribution characteristics and radar cross-section intensity of the corner reflectors, resulting in a more ideal radar target structure. Compared to the electromagnetic characteristics of currently used icosahedral corner reflectors, the quasi-dodecahedral corner reflector exhibits a smoother angular distribution of its radar cross-section, making it suitable for evaluating the technical capabilities of target detection and identification equipment and technologies, as well as for testing and evaluating tracking and guidance devices.

[0025] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0026] 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.

[0027] Figure 1 A schematic diagram illustrating the construction method of a quasi-dodecahedral corner reflector;

[0028] Figure 2 A schematic diagram showing the decomposition of one surface of an octahedral corner reflector frame into four faces;

[0029] Figure 3 A schematic diagram showing the rotation of the three non-central corner reflectors around the edge of the central corner reflector by an angle α;

[0030] Figure 4 To replicate the rotated four small reflector groups into all eight quadrants of space, a schematic diagram of the geometric model of the quasi-32-sided corner reflector is obtained;

[0031] Figure 5 A schematic diagram of the radar cross-section angular domain distribution curve of a quasi-32-sided corner reflector;

[0032] Figure 6 This is a schematic diagram of the angular domain distribution curve of the radar cross-section of an icosahedral corner reflector with the same outer contour dimensions. Detailed Implementation

[0033] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0034] Example 1

[0035] A specific embodiment of the present invention, such as Figure 1 As shown, a method for constructing a quasi-polyhedral omnidirectional radar wave scattering control structure is disclosed, including the following steps:

[0036] The first step is to construct an octahedral corner reflector frame, which contains eight surfaces, each of which is an equilateral triangle with side length *a*. The lines connecting the three vertices of the octahedron are defined as the X, Y, and Z axes, respectively. The preferred value for *a* is between 0.01 and 50 meters. The lines connecting the three vertices are defined as the origin of the Cartesian coordinate system XYZ, thus ensuring that each surface of the octahedron lies within one quadrant of the XYZ coordinate system.

[0037] As a type of regular polyhedron, the octahedral structure has high space utilization, and the geometric form of a single plane is an equilateral triangle, which is just right for arranging a right-angled trihedral reflector. However, if only eight right-angled trihedral reflectors are arranged in the entire space, the radar cross-section will produce relatively obvious fluctuations in the angular domain.

[0038] The second step involves using lines connecting the midpoints of the three sides of each surface to decompose each surface of the octahedral corner reflector frame into four small equilateral triangles. A corner reflector is placed at the position of each small equilateral triangle. Each corner reflector consists of three mutually perpendicular plane mirrors, each being an isosceles right triangle. Each side of a small equilateral triangle forms the base of an isosceles right triangle. The small equilateral triangles form the opening of the corner reflector. The side length of the opening is a / 2, and the edge length of the corner reflector is...

[0039] Taking the first quadrant along the positive XYZ axes as an example, the surface of the octahedral corner reflector frame in the first quadrant is decomposed into four small equilateral triangles. A corner reflector is placed at the position of each small equilateral triangle, and each small equilateral triangle constitutes the aperture of a corner reflector. The side length of the corner reflector aperture is a / 2, and the edge length of the reflector is... like Figure 2 As shown.

[0040] Since the three surrounding corner reflectors rotate at relatively small angles, the four corner reflectors are basically oriented in the same direction. The four corner reflectors can approximately maintain the scattering cross-sectional value of a corner reflector with one surface of an octahedron as its aperture.

[0041] The structures of other quadrants can be obtained by copying and rotating the first quadrant along the positive XYZ axis.

[0042] The third step involves treating the four corner reflectors on each surface as a single unit and moving them a distance g along the X, Y, and Z axes away from the center point of the octahedron. The preferred value for g is between 0.01 meters and 10 meters.

[0043] Considering that the center directions of the apertures of the four corner reflectors obtained from the decomposition are the same, such as Figure 3 As shown in the left figure, the orientation of the three non-central corner reflector units needs to be rotated. Direct rotation would result in height differences between the eight surfaces, making the surface of the quasi-polyhedral omnidirectional radar wave scattering control structure of this invention uneven. Therefore, it is necessary to move the four corner reflectors as a whole towards a direction away from the center of the octahedron. To ensure that the characteristics in each direction are the same, it is preferable to move the four corner reflectors by a distance g along the X, Y, and Z axes towards the direction away from the center point of the octahedron. Through this step, the eight surfaces of the octahedron are separated by a certain distance.

[0044] The fourth step involves rotating the three non-central corner reflectors on each surface around the edge of the central corner reflector toward the center of the octahedron by an angle α, so that the line connecting the vertex of each corner reflector and the center of the face points to the center point of the octahedron; thus connecting the edges of the eight surfaces to each other to form a quasi-polyhedral omnidirectional radar wave scattering control structure.

[0045] See Figure 2 Of the four corner reflectors on each surface, one is located in the center, and the other three surround the central corner reflector, each sharing an edge with the central corner reflector. See also Figure 3 By rotating the three non-central corner reflectors on each surface by an angle α around the edge of the central corner reflector toward the center of the octahedron, the line connecting the vertex of each corner reflector to the center of the aperture faces the octahedron, thus making the angular domain distribution of the backscattering cross-section of the corner reflector combination more uniform. Performing the same operation on all eight surfaces, by adjusting the values ​​of g and α, the edges of the eight surfaces can be connected to each other, forming a quasi-polyhedral omnidirectional radar wave scattering control structure, such as... Figure 4 As shown.

[0046] In some embodiments, after the three non-central corner reflectors have rotated in the fourth step, there are portions that extend beyond the quadrant in which the surface is located. In this case, it is necessary to cut off the structure extending beyond the quadrant along the coordinate axes to ensure the consistency of the structure in all eight quadrants of the space.

[0047] Furthermore, the construction method of the quasi-polyhedral omnidirectional radar wave scattering control structure in this embodiment 1 also includes a fifth step: calculating the radar cross-section and the angular domain distribution curve of the quasi-polyhedral omnidirectional radar wave scattering control structure using electromagnetic calculation software, adjusting parameters a, g, and α based on the calculation results, and iterating multiple times to obtain the final structure.

[0048] In the fifth step, if the calculated radar cross section is smaller than the expected value, the length 'a' is increased, and steps one through five are repeated; if the calculated radar cross section is larger than the expected value, the length 'a' is decreased, and steps one through five are repeated; if the calculated radar cross section is equal to the expected value, the final value of 'a' is obtained.

[0049] Furthermore, in the fifth step, a multi-radar cross-sectional area angle domain distribution curve estimation design is performed, and the geometric control parameters g and α are adjusted to obtain structural parameters with a more ideal angle domain distribution.

[0050] Specifically, the radar cross section angle domain distribution curve is estimated multiple times. If the average value of the curve is less than the preset value, then g is increased and steps three to five are repeated. If the average value of the curve is greater than the preset value, then g is decreased and steps three to five are repeated. If the average value of the curve is equal to the preset value, then g is the final value. The value of α gradually increases from 0, and the variance of the radar cross section angle domain distribution curve is calculated at the same time. When the variance reaches the minimum value, the corresponding α is the final value.

[0051] exist Figure 5 The displayed radar cross-section angular domain distribution curve shows that the quasi-32-sided corner reflector exhibits a very smooth trend, meeting the conditions for simple function fitting. The computational geometry parameters are a fixed azimuth angle of 45 degrees and a zenith angle increasing from 0 degrees to 90 degrees in 15-degree intervals. For comparison, a 20-sided corner reflector with the same outer contour dimensions is modeled and analyzed; its radar cross-section angular domain distribution curve is shown below. Figure 6 As shown, the distribution exhibits significant fluctuations. Comparative design examples demonstrate that the radar cross-section angular domain distribution characteristics of the quasi-32-sided corner reflector are more stable and smoother than those of the 20-sided corner reflector.

[0052] Based on the designed structure and dimensions of the corner reflector, prototypes were fabricated using machining and other methods. The plane mirror of the corner reflector is made of a flat metal plate, preferably made of materials with good electrical conductivity and corrosion resistance, such as steel and aluminum. According to the geometric arrangement and model of the corner reflector, the corner reflector support was fabricated using machining and 3D printing methods. Thirty-two corner reflectors were then fixed to the support using welding, bending, or bonding methods, thus obtaining a usable quasi-dodecahedral corner reflector.

[0053] For applications in marine and terrestrial environments, necessary requirements such as waterproofing and corrosion resistance must be considered, and structural details such as rainwater drainage holes should be reserved. Necessary radar cross-section measurements are performed on the prepared samples to obtain usable quasi-dodecahedral corner reflector samples.

[0054] Example 2

[0055] Embodiment 2 of the present invention relates to a quasi-polyhedral omnidirectional radar wave scattering control structure, such as... Figure 4 As shown, the control structure is obtained using the construction method described in Example 1. This quasi-polyhedral omnidirectional radar wave scattering control structure includes a corner reflector support and 32 corner reflectors fixed to the support.

[0056] The corner reflector bracket is a frame structure with 32 openings that form an approximate sphere, and can be fabricated using methods such as machining and 3D printing.

[0057] The corner reflector comprises three mutually perpendicular plane mirrors, each of which is an isosceles right triangle. The bases of the three isosceles right triangles form a smaller equilateral triangle, which is positioned at one of the 32 openings. The line connecting the vertex of each corner reflector to the center of the smaller equilateral triangle points to the center point of the corner reflector support.

[0058] In some preferred embodiments, rainwater holes are also included.

[0059] Compared with existing technologies, this invention adopts a quasi-dodecahedral shape, arranging right-angled trihedral corner reflectors on the thirty-two faces of the dodecahedron. This better balances the spatial angular domain stable distribution characteristics of the corner reflectors and the radar scattering cross-section intensity. The back-facing / monostatic radar scattering cross-section of the corner reflector combination is more uniformly distributed in the angular domain, making it a more ideal radar wave scattering structure. It can be applied to radar wave scattering control structural components of ships, vehicles, aircraft, etc., radar image measurement and detection recognition algorithm training of ships, vehicles, aircraft, etc., simulation training of modern strike equipment systems, and passive radar wave jamming devices.

[0060] 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 method for constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure, characterized in that, Comprising the following steps: First step, establishing an octahedral corner reflector framework, said framework comprising eight surfaces, each of said surfaces being an equilateral triangle with side length a, defining three vertex connecting lines of said octahedron as X, Y, Z axes; Second, each surface of the octahedral corner reflector frame is divided into four small equilateral triangles by connecting the midpoints of the three edges of each surface, and a corner reflector is arranged at the position of each small equilateral triangle, wherein the corner reflector comprises three mutually perpendicular plane mirrors, the plane mirrors are isosceles right triangles, and each edge of the small equilateral triangle constitutes a base of the isosceles right triangle; the small equilateral triangle constitutes a mouth surface of the corner reflector; the mouth surface of the corner reflector has a side length of a / 2, and the edge length of the corner reflector is Third step, moving each surface's four said corner reflectors as a whole along X, Y, Z axes in the direction away from the center point of said octahedron by a distance g; Fourth step, rotating each surface's three said corner reflectors other than the central one around the edge of the central said corner reflector towards the center direction of said octahedron by an angle α, so that the connecting line of each said corner reflector's vertex and the center of the face points to the center point of said octahedron; Connecting the edges of the eight surfaces to each other to form said quasi-polyhedral omnidirectional radar wave scattering regulation structure.

2. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure according to claim 1, wherein, The value range of a is 0.01 to 50 meters.

3. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure according to claim 1 or 2, wherein, The value range of g is 0.01 meters to 10 meters.

4. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure according to claim 3, wherein, After the rotation of said three said corner reflectors other than the central one of each surface is completed in the fourth step, the structure exceeding the quadrant where the surface is located is cut off.

5. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure of claim 1, wherein, Further comprising a fifth step, calculating the radar scattering cross-sectional area and the radar scattering cross-sectional area angle domain distribution curve of said quasi-polyhedral omnidirectional radar wave scattering regulation structure according to electromagnetic calculation software, adjusting parameters a, g, α according to the calculation results, and obtaining the final structure through multiple iterations.

6. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure according to claim 5, wherein, In the fifth step, if the calculated radar scattering cross-sectional area is smaller than the expected value, increase the length a, and repeat the first to fifth steps again; if the calculated radar scattering cross-sectional area is larger than the expected value, decrease the length a, and repeat the first to fifth steps again; if the calculated radar scattering cross-sectional area is equal to the expected value, the final value of a is obtained.

7. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure according to claim 6, wherein, In the fifth step, multiple radar scattering cross-sectional area angle domain distribution curve estimations are performed, if the average value of the curve is less than a preset value, increase g and repeat the third to fifth steps again; if the average value of the curve is greater than a preset value, decrease g and repeat the third to fifth steps again; if the average value of the curve is equal to a preset value, the g at this time is the final value; the value of α gradually increases from 0, and the variance of the radar scattering cross-sectional area angle domain distribution curve is calculated at the same time, when the variance reaches a minimum value, the corresponding α is the final value.

8. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure of claim 1, wherein, The plane mirror is composed of a metal flat plate.

9. The method of constructing a quasi-polyhedral omnidirectional radar wave scattering modulation structure according to any one of claims 8, wherein, The corner reflector is formed by welding, bending or bonding of said metal flat plate.

10. A quasi-polyhedral omnidirectional radar wave scattering regulation structure, obtained according to the construction method of any one of claims 1-9.

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