Antenna control method for three-dimensional transient imaging geological disaster monitoring radar

Abstract

The present application relates to a three-dimensional transient imaging geological disaster monitoring radar antenna control method, including: determining a reference array element in a spherical array according to a preset desired direction, configuring effective working array elements based on the reference array element; determining the beam width of the spherical array element according to the resolution of the spherical array imaging system, and then determining the effective synthetic aperture angle of the working array element; calculating the path difference, azimuth and elevation angle from any array element in the spherical array to the target point; and dynamically adjusting the working state of the antenna unit by sliding partitions. The radar antenna adopts a spherical array with equal arc length uniform layout, and the array elements adopt a one-transmit-multiple-receive mode, using continuous or pulse signals. The array elements are distributed on the sphere, receiving reflected signals from different directions, and performing coherent superposition processing on the received signals to synthesize an equivalent imaging effect of a large aperture array, thereby improving data acquisition efficiency and obtaining higher imaging quality.

Description

Technical Field

[0001] The present application relates to the field of three-dimensional imaging, and in particular to a three-dimensional transient imaging geological disaster monitoring radar antenna control method. Background Art

[0002] Geological disaster detection radar is widely used in the fields of landslide, debris flow, ground collapse, dangerous rock mass and road safety monitoring. By real-time monitoring of changes in the disaster site, the development trend and potential risks of the disaster are evaluated, providing a scientific basis for rescue decisions. Geological disaster monitoring radar places higher requirements on data real-time and high-resolution imaging. Currently, most linear array antennas are used for imaging, which has problems such as low data transmission and reception efficiency, low imaging quality and limited monitoring range. The three-dimensional transient imaging geological disaster monitoring radar relies on spherical array antenna wide-angle scanning, flexible beam control and one-transmit-multiple-receive scanning mode to achieve transient imaging. Summary of the invention

[0003] The embodiment of the present application provides a three-dimensional transient imaging geological disaster monitoring radar antenna control method, which improves data collection efficiency and obtains higher imaging quality.

[0004] According to one of the solutions of the present application, a three-dimensional transient imaging geological disaster monitoring radar antenna control method is provided, comprising:

[0005] According to a preset desired direction, a reference array element is determined in the spherical array, and effective working array elements are configured based on the reference array element;

[0006] Determine the beam width of the spherical array element according to the resolution of the spherical array imaging system, and then determine the effective synthetic aperture angle of the working array element;

[0007] Calculate the path difference, azimuth and elevation angle from any element of the spherical array to the target point;

[0008] Sliding partitions are used to dynamically adjust the working status of the antenna unit.

[0009] In some embodiments, according to a preset desired direction, a reference array element is determined in the spherical array, and the effective working array element is configured based on the reference array element, including:

[0010] According to the preset desired direction, the far-field observation point outside the spherical array antenna is set to , set the edge Z The axis direction is the reference direction, recorded as 0 degrees, and the target point P The pitch angle with the reference direction is , then the latitude arc corresponding to the selected reference array element m for:

[0011] ;

[0012] Where: , Indicates rounding operation. Indicates that the array elements are equally spaced along the pitch direction.

[0013] In some embodiments, the method further comprises: determining a reference array element in a spherical array according to a preset desired direction, and configuring effective working array elements based on the reference array element.

[0014] Set edge X The axis direction is the azimuth reference direction, recorded as 0 degrees, and the angle between the target point P and the reference direction along the azimuth is , the selected reference array element is:

[0015] ;

[0016] Indicates m The first An array element.

[0017] In some embodiments, determining the beam width of a spherical array element according to the resolution of the spherical array imaging system, and then determining the effective synthetic aperture angle of the working element, includes:

[0018] According to the azimuth angular resolution of the spherical array imaging radar and elevation angular resolution and operating frequency Calculating the beamwidth of a spherical array element and ;

[0019] ;

[0020] ;

[0021] in represents the azimuth beamwidth of the spherical array, Indicates half the beam width in azimuth. represents the azimuth angular resolution of the spherical array, represents the beam width of the spherical array in elevation direction, It indicates half the beam width in elevation direction. represents the angular resolution in elevation direction, represents the operating wavelength of the spherical imaging system, , k Represents the beam width coefficient, which is related to the current distribution on the antenna aperture.

[0022] In some embodiments, the method of determining the beam width of a spherical array element according to the resolution of the spherical array imaging system, and then determining the effective synthetic aperture angle of the working element, further includes:

[0023] According to the beam width, calculate the aperture angle composed of the effective synthetic array elements of the spherical array;

[0024] ;

[0025] represents the effective synthetic array aperture angle composed of the spherical array along the azimuth direction, Represents the effective synthetic array aperture angle along the elevation direction.

[0026] In some embodiments, calculating the path difference from any array element of the spherical array to the target point includes:

[0027] For any array element A on the spherical surface, its position in the spherical array coordinate system is , projected on the XOY plane as , there is a target point in the far field , the projection on the XOY plane is , define the distance of line segment AP as h , then the line segment ; In the triangle middle, , ;but

[0028] ;

[0029] ;

[0030] exist In case,

[0031] .

[0032] In some embodiments, calculating the azimuth from any element of the spherical array to the target point includes:

[0033] For any array element A in the spherical array, the line where OA is located is taken as the local coordinate system where A is located. Z Axis, define the local coordinate system as Axis, then That is AP and The angle of the axis,

[0034] ;

[0035] exist In the case of

[0036] ;

[0037] .

[0038] In some embodiments, calculating the pitch angle from any element of the spherical array to the target point includes:

[0039] Finding vectors in local coordinates ,set up , ;

[0040] ;

[0041] ;

[0042] Passing point A and The plane with normal vector , obtained from the point method of the plane equation The expression is:

[0043] ;

[0044] point To plane The distance d is:

[0045] ;

[0046] Perpendicular to the plane , PB is also perpendicular to the plane , so PB and parallel;

[0047] ;

[0048] ;

[0049] In plane Find any point C on the surface other than points A and B, such as , with vector The direction of the line is taken as the local coordinate system of the array element. The axis direction can be calculated according to the vector product theorem:

[0050] ;

[0051] ;

[0052] exist In the case of

[0053] .

[0054] In some embodiments, the working state of the antenna unit is dynamically adjusted by sliding partitions, including:

[0055] The calculated value of each array element and , the working state of the antenna array element is adjusted according to the antenna aperture angle, and the effective working array element can be obtained by synthesizing the aperture angle and the reference array element;

[0056] when and When it is smaller than the element radiation angle, the element is excited. and When the angle is greater than the element radiation angle, the element is not excited.

[0057] In some embodiments, the reference array element is switched, and when the target moves, each array element and will be changed. Due to the characteristics of the full spatial distribution of spherical array antennas, the spherical array is selected and The array element with the smallest angle facing the target is used as the reference element, and then the effective excitation element under the effective synthetic aperture angle is recalculated to achieve the switching of the effective synthetic array element antenna.

[0058] The three-dimensional transient imaging geological disaster monitoring radar antenna control method of various embodiments of the present application determines a reference array element in a spherical array at least according to a preset expected direction, and configures the effective working array element based on the reference array element; determines the beam width of the spherical array element according to the resolution of the spherical array imaging system, and then determines the effective synthetic aperture angle of the working array element; calculates the path difference, azimuth and pitch angle from any array element in the spherical array to the target point; uses sliding partitions to dynamically adjust the working state of the antenna unit, the radar antenna adopts a spherical array with equal arc length uniform layout, the array element adopts a one-transmit-multiple-receive mode, and uses continuous or pulse signals. Since the array elements are distributed on the sphere, they can receive reflected signals from different directions, and the received signals are coherently superimposed to synthesize an equivalent large-aperture array imaging effect. Compared with existing radars, data acquisition efficiency is improved and higher imaging quality is obtained.

[0059] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions in the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0061] Figure 1 A geometric structure diagram of a spherical array antenna according to an embodiment of the present application is shown;

[0062] Figure 2 A schematic diagram of an effective synthetic aperture angle of an embodiment of the present application is shown;

[0063] Figure 3 A schematic diagram of azimuth angles in a local coordinate system according to an embodiment of the present application is shown;

[0064] Figure 4 A schematic diagram of the pitch angle in a local coordinate system of an embodiment of the present application is shown;

[0065] Figure 5 A schematic diagram of adjusting array element excitation by sliding partitions according to an embodiment of the present application is shown;

[0066] Figure 6 A schematic flow chart of a three-dimensional transient imaging geological disaster monitoring radar antenna control method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0067] Various aspects and features of the present application are described herein with reference to the accompanying drawings.

[0068] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present application will occur to those skilled in the art.

[0069] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0070] These and other characteristics of the present application will become apparent from the following description of a preferred form of embodiment given as a non-limiting example with reference to the accompanying drawings.

[0071] It should also be understood that although the present application has been described with reference to some specific examples, those skilled in the art will be able to readily implement many other equivalent forms of the present application.

[0072] The above and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings.

[0073] Specific embodiments of the present application are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments applied for are merely examples of the present application, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that obscure the present application. Therefore, the specific structural and functional details applied for herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present application in a variety of ways with substantially any suitable detailed structure.

[0074] This specification may use the phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present application.

[0075] 3D transient imaging radar has the advantages of high precision, high resolution, high speed and high reliability. It can obtain a large amount of scanning information in a short time and realize 3D visualization. It is widely used in geological disaster monitoring, road monitoring, tunnel monitoring, slope monitoring and other fields.

[0076] In combination with the above-mentioned background technology, this application describes the corresponding solutions in the form of embodiments to solve the defects in the prior art, but it is not intended to limit the scope of protection of the patent right claimed in this application.

[0077] As one of the solutions, Figures 1 to 6 As shown, the embodiment of the present application provides a three-dimensional transient imaging geological disaster monitoring radar antenna control method, including:

[0078] According to a preset desired direction, a reference array element is determined in the spherical array, and effective working array elements are configured based on the reference array element;

[0079] Determine the beam width of the spherical array element according to the resolution of the spherical array imaging system, and then determine the effective synthetic aperture angle of the working array element;

[0080] Calculate the path difference, azimuth and elevation angle from any element of the spherical array to the target point;

[0081] Sliding partitions are used to dynamically adjust the working status of the antenna unit.

[0082] In view of the contents mentioned above, the present application at least aims to propose a three-dimensional transient imaging geological disaster monitoring radar antenna control method. In view of the problems existing in the prior art, the radar antenna adopts a spherical array with uniform arc length layout, and the array elements adopt a one-transmit-multiple-receive mode, using continuous or pulse signals. Since the array elements are distributed on the spherical surface, they can receive reflected signals from different directions, and perform coherent superposition processing on the received signals, thereby synthesizing an equivalent large-aperture array imaging effect. Compared with existing radars, the data acquisition efficiency is improved and higher imaging quality is obtained.

[0083] The array element arrangement range is as follows Figure 1 The schematic diagram of the spherical array imaging antenna layout is shown in the figure. The azimuth direction is arranged in all directions at a 360° angle, and the elevation direction can generally be arranged at a maximum of 270°. Indicates The azimuth of the array element, Indicates On the basis of ensuring the imaging quality, in order to more flexibly improve the degree of freedom of distribution between array elements and meet the minimum spacing limit of adjacent array elements, the distribution of spherical array elements is divided.

[0084] Exemplary, combined Figure 6 A flow chart of the configuration method of a three-dimensional transient imaging geological disaster monitoring radar antenna control method of an embodiment of the present application is shown. The following takes steps S1 to S4 as an example to further illustrate the three-dimensional transient imaging geological disaster monitoring radar antenna layout method of the present application.

[0085] Step S1: according to a preset desired direction, a reference center array element is determined in the spherical array antenna, and the working array elements of the spherical array antenna are configured based on the reference array element.

[0086] like Figure 1 The figure shows the geometric structure of the spherical array antenna. The array elements are arranged in an equal arc length manner. The azimuth direction is arranged in an all-round angle of 360°. The elevation direction is generally less than 360° due to the limitation of the assembly space. Indicates A The azimuth of the array element, Indicates A The pitch angle of the array element, Indicates the target point P The azimuth of Indicates the target point P The pitch angle, r Indicates the distance from the center of the sphere. Each independent array element is evenly spaced on each dimensional arc to ensure uniform coverage of the entire spherical space. The number and density of array elements will affect the resolution and accuracy of imaging. When arranging the array, it is necessary to make a reasonable layout based on the application scenario and imaging requirements.

[0087] Based on step S1 of the embodiment, the present application may further include step S2.

[0088] Step S2: according to the preset expected direction, a reference array element is determined in the spherical array, and effective working array elements are configured based on the reference array element.

[0089] According to the preset desired direction, the far-field observation point outside the spherical array antenna is set to , set the edge Z The axis direction is the reference direction, recorded as 0 degrees, and the target point P The pitch angle with the reference direction is , then the latitude arc corresponding to the selected reference array element m for:

[0090] (1)

[0091] Where: , Indicates rounding operation. Indicates that the array elements are equally spaced along the pitch direction.

[0092] Set edge X The axis direction is the azimuth reference direction, recorded as 0 degrees, and the angle between the target point P and the reference direction along the azimuth is , then the selected reference array element is:

[0093] (2)

[0094] Indicates m The first The reference array element can be determined according to formulas (1) and (2).

[0095] According to the azimuth angular resolution of the spherical array imaging radar and elevation angular resolution and operating frequency Calculating the beamwidth of a spherical array element and :

[0096] (3)

[0097] (4)

[0098] in, represents the azimuth beamwidth of the spherical array, Indicates half the beam width in azimuth. represents the azimuth angular resolution of the spherical array, represents the beam width of the spherical array in elevation direction, It indicates half the beam width in elevation direction. represents the angular resolution in elevation direction, represents the operating wavelength of the spherical imaging system, , k represents the beam width coefficient, which is related to the current distribution on the antenna aperture and is generally taken as 0.886.

[0099] According to the beam width, calculate the aperture angle composed of the effective synthetic array elements of the spherical array;

[0100] (5)

[0101] represents the effective synthetic array aperture angle composed of the spherical array along the azimuth direction, Represents the effective synthetic array aperture angle along the elevation direction. Figure 2 Shown is a schematic diagram of array element distribution corresponding to the effective synthetic aperture angle.

[0102] Based on step S2 of the embodiment, the present application may further include step S3.

[0103] The spherical array synthetic aperture principle involves the arrangement of the spherical array, signal transmission and reception, and the process of improving imaging resolution through synthetic aperture technology.

[0104] The spherical array is composed of multiple array elements arranged in a spherical shape. This arrangement enables the array to cover a wider range of spatial angles, thereby capturing signals from different directions.

[0105] In the received transmitted signal, due to the different positions of the array elements, the time when the signal arrives at each array element will be different, resulting in phase differences between the signals. In order to achieve coherent superposition, these signals must first be phase compensated so that all signals can be added in phase when superimposed. Phase compensation is usually achieved through signal processing algorithms, including steps such as time delay estimation and phase adjustment.

[0106] Step S3: Calculate the path difference, azimuth angle and elevation angle from any element of the spherical array to the target point.

[0107] Calculate the path difference from any element of the spherical array to the target point: Figure 1 The position of any array element A on the spherical surface shown in the spherical array coordinate system is , projected on the XOY plane as There is a target point in the far field , the projection on the XOY plane is , define the distance of line segment AP as h, then the line segment In the triangle middle, , According to the cosine theorem, the path difference between any array elements can be calculated using formulas (6) and (7);

[0108] (6)

[0109] (7)

[0110] Preferred ;

[0111] Therefore, for the above formula, the path difference of each array element can be calculated according to formula (8);

[0112] (8)

[0113] The phase difference can be calculated through the path difference, and then coherent superposition can be achieved through phase compensation.

[0114] In the local coordinate system, each array element is relative to the target point Azimuth Calculation: Figure 3 As shown in the figure, for any element A in the spherical array, the line where OA is located is taken as the local coordinate system where A is located. Z Axis, define the local coordinate system as Axis, then That is AP and The angle between the axes can be calculated according to formula (9):

[0115] (9)

[0116] in , then

[0117] (10)

[0118] (11)

[0119] in and , Related to, between different array elements , Different from each other, so Is unique.

[0120] In the local coordinate system, each array element is relative to the target point Pitch angle Calculation: First find the vector ,like Figure 4 The settings shown , , then:

[0121] (12)

[0122] (13)

[0123] Passing point A and The plane with normal vector , obtained from the point method of the plane equation The expression is:

[0124] (14)

[0125] point To plane The distance d is:

[0126] (15)

[0127] Perpendicular to the plane , PB is also perpendicular to the plane , so PB and Parallel; Calculate the vector according to formula (16) :

[0128] (16)

[0129] According to formula (17), we can find :

[0130] (17)

[0131] In plane Find any point C on the surface other than points A and B, such as , with vector The direction of the line is taken as the local coordinate system of the array element. The axis direction can be calculated according to the vector product theorem:

[0132] (18)

[0133] (19)

[0134] in , calculated according to formula (20) :

[0135] (20)

[0136] in, and , Regarding different array elements , The angles are different, corresponding to the only .

[0137] Based on step S3 of the embodiment, the present application may further include step S4.

[0138] Step S4: Dynamically adjust the working state of the antenna unit using sliding partitions.

[0139] The calculated value of each array element and , adjust the working state of the antenna array element according to the antenna aperture angle, and the effective working array element can be obtained by synthesizing the aperture angle and the reference array element. Figure 5 The figure shows the schematic diagram of adjusting the excitation of the array element by sliding partitions under the spherical array section. and When it is smaller than the element radiation angle, the element is excited. and When the angle is greater than the element radiation angle, the element is not excited.

[0140] Reference array element switching, when the target moves, each array element and will be changed. Due to the characteristics of the full spatial distribution of spherical array antennas, the spherical array is selected and The array element with the smallest angle (i.e., facing the target object) is used as the reference element, and the effective excitation element under the effective synthetic aperture angle is recalculated to achieve the switching of the effective synthetic array element antenna.

[0141] In some specific embodiments, the present application provides a configuration device for a three-dimensional transient imaging geological disaster monitoring radar antenna, including one or more processing modules, configured to execute the specific implementation methods of steps S1 to S4 in the above text.

[0142] Specifically, one of the inventive concepts of the present application is to establish, on the basis of a three-dimensional transient imaging geological disaster monitoring radar antenna, determine a reference array element in a spherical array at least according to a preset expected direction, and configure the effective working array element based on the reference array element; determine the beam width of the spherical array element according to the resolution of the spherical array imaging system, and then determine the effective synthetic aperture angle of the working array element; calculate the path difference, azimuth and pitch angle from any array element in the spherical array to the target point; use sliding partitions to dynamically adjust the working state of the antenna unit, so that by controlling the excitation of the spherical array antenna element, the effective synthetic array element is quickly switched and scanned, and the coherent superposition processing of the signal is completed. An equivalent large-aperture antenna is simulated through the synthetic aperture to achieve higher resolution and a wider viewing angle range, which can capture and identify smaller and more transient objects, and improve the imaging resolution and clarity.

[0143] The present application also provides a computer-readable storage medium on which computer executable instructions are stored. When the computer executable instructions are executed by a processor, the three-dimensional transient imaging geological disaster monitoring radar antenna control method according to the configuration described above is mainly implemented, which at least includes:

[0144] According to a preset desired direction, a reference array element is determined in the spherical array, and effective working array elements are configured based on the reference array element;

[0145] Determine the beam width of the spherical array element according to the resolution of the spherical array imaging system, and then determine the effective synthetic aperture angle of the working array element;

[0146] Calculate the path difference, azimuth and elevation angle from any element of the spherical array to the target point;

[0147] Sliding partitions are used to dynamically adjust the working status of the antenna unit.

[0148] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A three-dimensional transient imaging geological disaster monitoring radar antenna control method, comprising: According to a preset desired direction, a reference array element is determined in the spherical array, and effective working array elements are configured based on the reference array element; Determine the beam width of the spherical array element according to the resolution of the spherical array imaging system, and then determine the effective synthetic aperture angle of the working array element; Calculate the path difference, azimuth and elevation angle from any element of the spherical array to the target point; Use sliding partitions to dynamically adjust the working status of antenna units; Wherein, according to a preset desired direction, a reference array element is determined in the spherical array, and effective working array elements are configured based on the reference array element, including: According to the preset desired direction, the far-field observation point outside the spherical array antenna is set to , set the edge Z The axis direction is the reference direction, recorded as 0 degrees, and the target point P The pitch angle with the reference direction is , then the latitude arc corresponding to the selected reference array element m for: ； Where: , Indicates rounding operation. Indicates that the array elements are equally spaced along the pitch direction; The beam width of the spherical array element is determined according to the resolution of the spherical array imaging system, and then the effective synthetic aperture angle of the working element is determined, including: According to the azimuth angular resolution of the spherical array imaging radar and elevation angular resolution and operating frequency Calculating the beamwidth of a spherical array element and ; ； ； in represents the azimuth beamwidth of the spherical array, Indicates half the beam width in azimuth. represents the azimuth angular resolution of the spherical array, represents the beam width of the spherical array in elevation direction, It indicates half the beam width in elevation direction. represents the angular resolution in elevation direction, represents the operating wavelength of the spherical imaging system, , k It represents the beam width coefficient, which is related to the current distribution on the antenna aperture; According to the beam width, calculate the aperture angle composed of the effective synthetic array elements of the spherical array; ； represents the effective synthetic array aperture angle composed of the spherical array along the azimuth direction, represents the effective synthetic array aperture angle along the elevation direction; Calculate the path difference from any element of the spherical array to the target point, including: For any array element A on the spherical surface, its position in the spherical array coordinate system is , projected on the XOY plane as , there is a target point in the far field , the projection on the XOY plane is , define the distance of line segment AP as h , then the line segment ; In the triangle middle, , ;but exist In case, ； Calculate the azimuth from any element of the spherical array to the target point, including: For any array element A in the spherical array, the line where OA is located is taken as the local coordinate system where A is located. Z Axis, define the local coordinate system as Axis, then That is AP and The angle of the axis, ； exist In the case of ； ； Calculate the pitch angle from any element of the spherical array to the target point, including: Finding vectors in local coordinates ,set up , ; ； ； Passing point A and The plane with normal vector , obtained from the point method of the plane equation The expression is: ； point To plane The distance d is: Perpendicular to the plane , PB is also perpendicular to the plane , so PB and parallel; ； ； In plane Find any point C on the surface other than points A and B, such as , with vector The direction of the line is taken as the local coordinate system of the array element. The axis direction can be calculated according to the vector product theorem: ； exist In the case of ； The sliding partition is used to dynamically adjust the working status of the antenna unit, including: The calculated value of each array element and , the working state of the antenna array element is adjusted according to the antenna aperture angle, and the effective working array element can be obtained by synthesizing the aperture angle and the reference array element; when and When it is smaller than the array element radiation angle, the array element is excited. and When the angle is greater than the element radiation angle, the element is not excited.

2. The method according to claim 1, wherein: According to a preset desired direction, a reference array element is determined in the spherical array, and effective working array elements are configured based on the reference array element, further comprising: Set edge X The axis direction is the azimuth reference direction, recorded as 0 degrees, and the angle between the target point P and the reference direction along the azimuth is , the selected reference array element is: ； Indicates m The first An array element.

3. According to the method of claim 1, the reference array element switching, when the target moves, each array element and will be changed. Due to the characteristics of the full spatial distribution of spherical array antennas, the spherical array is selected and The array element with the smallest angle facing the target is used as the reference element, and then the effective excitation element under the effective synthetic aperture angle is recalculated to achieve the switching of the effective synthetic array element antenna.

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