A method and apparatus for array radar pattern synthesis of space-time joint modulation

Abstract

This invention proposes a method and apparatus for synthesizing array radar radiation patterns using space-time joint modulation. The method includes: determining initial values ​​of the array radar element excitation coefficients; acquiring the array far-field radiation pattern under the influence of the initial values ​​of the element excitation coefficients; dividing the array far-field radiation pattern into main lobe and side lobe regions based on its characteristics; setting the random modulation phase of the main lobe region to zero, maintaining the same main lobe phase across different pulses, while modulating the phase of the side lobe region regularly or randomly, while keeping the array far-field radiation pattern amplitude constant, thus obtaining array radiation patterns with different phase characteristics under multiple pulses; performing Fourier transforms on the array radiation patterns under different pulses to obtain the space-time two-dimensional element excitation coefficients; and applying the space-time two-dimensional element excitation coefficients to the array radar system to synthesize the array radar radiation pattern after space-time joint modulation. This invention significantly improves the array radar's resistance to sidelobe clutter and interference.

Description

Technical Field

[0001] This invention belongs to the field of array radar technology, and in particular relates to a method and apparatus for pattern synthesis of array radar using space-time joint modulation. Background Technology

[0002] Radar, as an all-weather, all-time, and long-range detection method, has been widely used in fields such as cruise detection and precision guidance. Array radar, on the other hand, is a radar system containing multiple sets of transmitting and receiving antennas, possessing various performance advantages such as high gain and low sidelobes. However, in practical radar systems, sidelobe interference and clutter in complex electromagnetic environments significantly impact the detection performance of array radar systems. Array pattern synthesis is one of the effective technical means to improve the detection and anti-jamming performance of array radar.

[0003] Array pattern synthesis can achieve the required radiation characteristics of array antennas in different application scenarios by controlling parameters such as array element position, excitation amplitude, and phase. Existing array pattern synthesis methods typically optimize array element parameters only in the spatial dimension, which cannot fully meet the radiation characteristic requirements of practical systems. Especially when the array aperture is limited, it is difficult to achieve ultra-low levels in the pattern sidelobes, which greatly limits the application of array radar in environments with sidelobe interference and clutter. In view of this, this invention adopts the idea of ​​dual-degree-of-freedom optimization control in the spatial and slow-time dimensions, and proposes a space-time joint modulation array radar pattern synthesis method and system, which has the characteristics of simplicity, efficiency, and wide applicability. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention proposes a method and apparatus for combining array radar patterns using space-time joint modulation.

[0005] On one hand, the present invention provides a method for synthesizing the radiation pattern of an array radar using space-time joint modulation, comprising:

[0006] Determine the initial values ​​of the array element excitation coefficients for the array radar;

[0007] Obtain the array far-field pattern under the influence of the initial values ​​of the array element excitation coefficients;

[0008] Based on the characteristics of the array far-field pattern, it is divided into a main lobe region and a side lobe region. The random modulation phase of the main lobe region is set to zero, so that the main lobe phase of the array far-field pattern is the same between different pulses. Meanwhile, the phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array far-field pattern unchanged, so as to obtain array patterns with different phase characteristics under multiple pulses.

[0009] Fourier transform is performed on the array pattern under different pulses to obtain the excitation coefficients of the space-time two-dimensional array elements;

[0010] By applying the excitation coefficients of the two-dimensional array elements in space and time to the array radar system, the combined space-time modulated array radar pattern is obtained.

[0011] On the other hand, the present invention provides a space-time joint modulation array radar pattern synthesis device, comprising:

[0012] The first module is used to determine the initial values ​​of the array element excitation coefficients of the array radar;

[0013] The second module is used to obtain the array far-field pattern under the action of the initial values ​​of the array element excitation coefficients;

[0014] The third module is used to divide the array far-field pattern into a main lobe region and a side lobe region according to the characteristics of the array far-field pattern. The random modulation phase of the main lobe region is set to zero, so that the main lobe phase of the array far-field pattern is the same between different pulses. The phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array far-field pattern unchanged, so as to obtain array patterns with different phase characteristics under multiple pulses.

[0015] The fourth module is used to perform Fourier transform on the array pattern under different pulses, thereby obtaining the excitation coefficients of the space-time two-dimensional array elements.

[0016] The fifth module is used to apply the excitation coefficients of the space-time two-dimensional array elements to the array radar system, and to obtain the array radar pattern after space-time joint modulation.

[0017] Furthermore, in the fourth module, based on the space-time two-dimensional array element excitation coefficient matrix... The relationship between the Fourier transform pairs of the array pattern and the array pattern. Fourier transforms were performed on the array patterns of each pulse with different phase characteristics, and the Fourier transform results were truncated, taking the first few pulses. N A number of values, from which we obtain Spacetime two-dimensional array element excitation coefficient matrix .

[0018] On the other hand, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0019] Determine the initial values ​​of the array element excitation coefficients for the array radar;

[0020] Obtain the array far-field pattern under the influence of the initial values ​​of the array element excitation coefficients;

[0021] Based on the characteristics of the array far-field pattern, it is divided into a main lobe region and a side lobe region. The random modulation phase of the main lobe region is set to zero, so that the main lobe phase of the array far-field pattern is the same between different pulses. Meanwhile, the phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array far-field pattern unchanged, so as to obtain array patterns with different phase characteristics under multiple pulses.

[0022] Fourier transform is performed on the array pattern under different pulses to obtain the excitation coefficients of the space-time two-dimensional array elements;

[0023] By applying the excitation coefficients of the two-dimensional array elements in space and time to the array radar system, the combined space-time modulated array radar pattern is obtained.

[0024] On the other hand, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, performs the following steps:

[0025] Determine the initial values ​​of the array element excitation coefficients for the array radar;

[0026] Obtain the array far-field pattern under the influence of the initial values ​​of the array element excitation coefficients;

[0027] Based on the characteristics of the array far-field pattern, it is divided into a main lobe region and a side lobe region. The random modulation phase of the main lobe region is set to zero, so that the main lobe phase of the array far-field pattern is the same between different pulses. Meanwhile, the phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array far-field pattern unchanged, so as to obtain array patterns with different phase characteristics under multiple pulses.

[0028] Fourier transform is performed on the array pattern under different pulses to obtain the excitation coefficients of the space-time two-dimensional array elements;

[0029] By applying the excitation coefficients of the two-dimensional array elements in space and time to the array radar system, the combined space-time modulated array radar pattern is obtained.

[0030] The beneficial effects obtained by using this invention are:

[0031] This invention introduces a slow-time dimension modulation degree of freedom. It employs a method where the phase of the main lobe region remains unchanged while the phase of the side lobe region is randomly modulated for multiple pulse array patterns. This method solves for the inter-pulse agile space-time two-dimensional array element excitation coefficients, achieving space-time joint modulation synthesis of the array pattern. It has the advantages of simple solution process and good synthesis performance. Compared with the traditional array pattern synthesis method that only uses spatial dimension modulation, it greatly improves the array radar's performance against sidelobe clutter and interference, and is easy to implement in practical applications. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0033] Figure 1 A flowchart illustrating a method for pattern synthesis of an array radar using space-time joint modulation, as provided in one embodiment;

[0034] Figure 2 This is a composite array pattern obtained using the method of the present invention in one embodiment, wherein the number of uniform linear array elements is set. Array element spacing , Using the signal wavelength, the array pattern under 32 pulses in the slow time dimension is spatiotemporally jointly modulated using the method of this invention, and sidelobe regions are set. The phase modulation is The array pattern is synthesized using the obtained two-dimensional excitation coefficient matrix of space and time to obtain the final pattern synthesis result. Among them, (a) is the array pattern space-time joint modulation result when the initial values ​​of the excitation coefficients of the selected array elements are all 1, and (b) is the array pattern space-time joint modulation result when the initial values ​​of the excitation coefficients of the selected array elements are Kaiser windows. Specific implementation methods

[0035] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0036] Figure 1 The flowchart of this invention shows that this invention provides a method for synthesizing the radiation pattern of an array radar using joint space-time modulation, comprising:

[0037] (S1) Determine the initial values ​​of the array element excitation coefficients of the array radar;

[0038] (S2) Obtain the array far-field pattern under the action of the initial values ​​of the array element excitation coefficients;

[0039] (S3) Obtain array patterns with different phase characteristics under multiple pulses;

[0040] Based on the characteristics of the array far-field pattern, it is divided into a main lobe region and a side lobe region. The random modulation phase of the main lobe region is set to zero, so that the main lobe phase of the array far-field pattern is the same between different pulses. Meanwhile, the phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array far-field pattern unchanged, so as to obtain array patterns with different phase characteristics under multiple pulses.

[0041] (S4) Perform Fourier transform on the array pattern under different pulses to obtain the excitation coefficients of the space-time two-dimensional array elements;

[0042] (S5) Apply the excitation coefficients of the two-dimensional array elements in space and time to the array radar system to obtain the array radar pattern after space-time joint modulation.

[0043] The specific structural form of the array radar in this invention is not limited, the number of array elements of the array radar is not limited, and the spacing between array elements is not limited. Those skilled in the art can apply the method of this invention to different forms of array radar.

[0044] Without loss of generality, taking a uniform linear array as an example, that is, the array radar is a uniform linear array, and the number of array elements is... The spacing between array elements is , among which, the The excitation coefficient of each array element is Based on different application scenarios or radar system design requirements, the initial values ​​of the excitation coefficients for all array elements are set to... .

[0045] Initial values ​​of array element excitation coefficients There are no restrictions on the setting method. Depending on the different application scenarios or radar system design requirements, those skilled in the art can make reasonable settings based on their own experience, common knowledge in the field, and conventional methods.

[0046] In one embodiment, the initial value of the array element excitation coefficient is set to... .

[0047] In another embodiment, the initial value of the array element excitation coefficient is set to a length of... The window functions include, but are not limited to, Taylor windows, Hanning windows, and Kaiser windows. .

[0048] In another embodiment, based on the radiation characteristics requirements of the array elements, a set of elements with a length of [missing information] is designed and solved. The excitation coefficient is used as the initial value of the array element excitation coefficient.

[0049] In step (S2) of one embodiment, assuming the array element is an omnidirectional antenna, taking a uniform linear array as an example, the far-field radiation pattern of the array under the action of the initial value of the array element excitation coefficient can be expressed as:

[0050] ;

[0051] in, , Indicates the wavelength of the array radar signal. This indicates the angle between the array normal direction and the beam direction.

[0052] Next, based on the characteristics of the array's far-field pattern, it can be divided into main lobe regions. and the side lobe region The phase of the main lobe region and the phase of the side lobe region of the array far-field pattern are modulated respectively:

[0053] ;

[0054] in, For the first Phase modulation factor of the array far-field pattern under pulse.

[0055] In practice, depending on different application requirements, binary phase shift keying, quadrature phase shift encoding, etc., can be selected, as follows:

[0056] (11)

[0057] In other words, the main lobe is randomly modulated with a phase of 0, maintaining the same main lobe phase across different pulses, while the sidelobe phases are modulated regularly or randomly, while keeping the array pattern amplitude constant. This allows for the synthesis of the... The array pattern with different phase characteristics of each pulse is shown below:

[0058] ;

[0059] Furthermore, the spatiotemporal joint modulation of the array pattern is refined, and in equation (12) Different pattern functions can be selected, as follows:

[0060] ;

[0061] right The array pattern with different phase characteristics of each pulse is subjected to Fourier transform, as follows:

[0062] ;

[0063] in, Indicates along the angle Fourier transform of dimensionality; This indicates that the Fourier transform result is truncated, taking the first few digits. A number; This represents taking the real part of a complex number; from this, we can obtain... Spacetime two-dimensional array element excitation coefficient matrix .

[0064] Finally, the excitation coefficient matrix of the space-time two-dimensional array elements is... By applying the received echo to the array radar, the combined spatial-temporal modulated array radar pattern can be obtained.

[0065] To illustrate the effectiveness of this invention, a specific application example is provided below:

[0066] Figure 2 This is a composite array pattern obtained using the method of the present invention in one embodiment, wherein the number of uniform linear array elements is set. Array element spacing , Using the signal wavelength, the array pattern under 32 pulses in the slow time dimension is spatiotemporally jointly modulated using the method of this invention, and sidelobe regions are set. The phase modulation is The array pattern was synthesized using the solved two-dimensional excitation coefficient matrix to obtain the final pattern synthesis result. (a) shows the array pattern spatial-temporal joint modulation result when all selected element excitation coefficients are initially set to 1, and (b) shows the array pattern spatial-temporal joint modulation result when the selected element excitation coefficients are initially set to a Kaiser window value. Comparing the patterns before and after synthesis, it can be seen that the spatial-temporal joint modulation results in a lower sidelobe level and better resistance to sidelobe clutter and interference.

[0067] On the other hand, one embodiment provides a space-time co-modulated array radar pattern synthesis device, comprising:

[0068] The first module is used to determine the initial values ​​of the array element excitation coefficients of the array radar;

[0069] The second module is used to obtain the array far-field pattern under the action of the initial values ​​of the array element excitation coefficients;

[0070] The third module is used to divide the array far-field pattern into a main lobe region and a side lobe region according to the characteristics of the array far-field pattern. The random modulation phase of the main lobe region is set to zero, so that the main lobe phase of the array far-field pattern is the same between different pulses. The phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array far-field pattern unchanged, so as to obtain array patterns with different phase characteristics under multiple pulses.

[0071] The fourth module is used to perform Fourier transform on the array pattern under different pulses, thereby obtaining the excitation coefficients of the space-time two-dimensional array elements.

[0072] The fifth module is used to apply the excitation coefficients of the space-time two-dimensional array elements to the array radar system, and to obtain the array radar pattern after space-time joint modulation.

[0073] Furthermore, in the fourth module, based on the space-time two-dimensional array element excitation coefficient matrix... The relationship between the Fourier transform pairs of the array pattern and the array pattern. Fourier transforms were performed on the array patterns of each pulse with different phase characteristics, and the Fourier transform results were truncated, taking the first few pulses. N A number of values, from which we obtain Spacetime two-dimensional array element excitation coefficient matrix .

[0074] The implementation methods of the above modules and the construction of the model can all adopt the methods described in any of the foregoing embodiments, and will not be repeated here.

[0075] On the other hand, the present invention provides a computer device including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the space-time joint modulation array radar pattern synthesis method provided in any of the above embodiments. The computer device can be a server. The computer device can be an embedded system, such as an FPGA, or it can be an offline processing system that applies coefficients to an online system. The computer device includes a processor, a memory, a network interface, and a database connected via a system bus. The processor of the computer device provides computational and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device stores sample data. The network interface of the computer device is used for communication with external terminals via a network connection.

[0076] On the other hand, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps of the array radar pattern synthesis method of space-time joint modulation provided in any of the above embodiments.

[0077] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0078] Matters not covered in this invention are common knowledge.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for synthesizing the radiation pattern of an array radar using space-time joint modulation, characterized in that, include: Determine the initial values ​​of the array element excitation coefficients for the array radar, wherein the array radar is a uniform linear array, and the number of array elements is set to be... The spacing between array elements is , among which, the The excitation coefficient of each array element is Based on different application scenarios or radar system design requirements, the initial values ​​of the excitation coefficients for all array elements are set to... ; Obtain the array far-field pattern under the influence of the initial values ​​of the array element excitation coefficients; Based on the characteristics of the array's far-field radiation pattern, it is divided into a main lobe region and a side lobe region. The random modulation phase of the main lobe region is set to zero, ensuring that the main lobe phase of the array's far-field radiation pattern is the same across different pulses. Meanwhile, the phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array's far-field radiation pattern constant. This yields array radiation patterns with different phase characteristics under multiple pulses, where... For the first The phase modulation factor of the array far-field pattern under each pulse modulates the phase of the sidelobe region in a regular or random manner. in This represents the sidelobe region of the array's far-field pattern; This indicates the angle between the array normal direction and the beam direction; No. The array pattern with different phase characteristics of the pulses is as follows: in Different pattern functions were selected, as follows: Fourier transform is performed on the array pattern under different pulses to obtain the excitation coefficients of the space-time two-dimensional array elements; By applying the excitation coefficients of the two-dimensional array elements in space and time to the array radar system, the combined space-time modulated array radar pattern is obtained.

2. The array radar pattern synthesis method based on spatiotemporal joint modulation according to claim 1, characterized in that, Set the initial values ​​of the array element excitation coefficients .

3. The array radar pattern synthesis method based on spatiotemporal joint modulation according to claim 1, characterized in that, The initial value of the array element excitation coefficient is set to a length of... The window functions include Taylor window, Hanning window, and Kaiser window.

4. The array radar pattern synthesis method based on spatiotemporal joint modulation according to claim 1, characterized in that, Based on the requirements of the array element radiation characteristics, a set of lengths was designed and solved. The excitation coefficient is used as the initial value of the array element excitation coefficient.

5. The array radar pattern synthesis method based on spatiotemporal joint modulation according to any one of claims 1 to 4, characterized in that, right The excitation coefficients of the space-time two-dimensional array elements are obtained by performing Fourier transforms on the array pattern with different phase characteristics of each pulse. : in, Indicates along the angle Fourier transform of dimensionality; This indicates that the Fourier transform result is truncated, taking the first few digits. N A number; This indicates taking the real part of a complex number; Therefore, we obtain Spacetime two-dimensional array element excitation coefficient matrix .

6. A space-time co-modulated array radar pattern synthesis device, used to implement the space-time co-modulated array radar pattern synthesis method as described in claim 1, characterized in that, include: The first module is used to determine the initial values ​​of the array element excitation coefficients of the array radar; The second module is used to obtain the array far-field pattern under the action of the initial values ​​of the array element excitation coefficients; The third module is used to divide the array far-field pattern into a main lobe region and a side lobe region according to the characteristics of the array far-field pattern. The random modulation phase of the main lobe region is set to zero, so that the main lobe phase of the array far-field pattern is the same between different pulses. The phase of the side lobe region is modulated regularly or randomly, while keeping the amplitude of the array far-field pattern unchanged, so as to obtain array patterns with different phase characteristics under multiple pulses. The fourth module is used to perform Fourier transform on the array pattern under different pulses, thereby obtaining the excitation coefficients of the space-time two-dimensional array elements. The fifth module is used to apply the excitation coefficients of the space-time two-dimensional array elements to the array radar system, and to obtain the array radar pattern after space-time joint modulation.

7. The array radar pattern synthesizer with space-time joint modulation according to claim 6, characterized in that, In the fourth module, based on the space-time two-dimensional array element excitation coefficient matrix The relationship between the Fourier transform pairs of the array pattern and the array pattern. Fourier transforms were performed on the array patterns of each pulse with different phase characteristics, and the Fourier transform results were truncated, taking the first few pulses. N A number of values, from which we obtain Spacetime two-dimensional array element excitation coefficient matrix .

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