Angle measurement method for arbitrary subarray architecture radar

Abstract

This invention provides an angle measurement method, storage medium, and electronic device applicable to radars with arbitrary subarray architectures, relating to the field of radar technology. In this invention, firstly, the radar array is divided into several subarrays based on mission requirements, and subarray-level beamforming is performed to construct a subarray echo signal vector model. Secondly, a calibration signal inversion method is used to estimate the subarray phase center. Thirdly, a subarray phase gradient vector is constructed. Finally, a weighted phase gradient method is used to estimate the phase gradient centroid to obtain the target angle measurement result. This method uses the phase gradient as the basis for angle measurement. It normalizes the phase difference between subarrays by the spacing between adjacent subarrays, ensuring that the phase difference between different subarray spacings is only related to the target angle and independent of the subarray length. Therefore, it can be applied to radar antenna arrays with arbitrary subarray divisions, reducing antenna design limitations. Furthermore, the subarray synthesis further reduces the computational scale and improves the real-time computing performance of the system.

Description

Technical Field

[0001] This invention relates to the field of radar technology, and more specifically to an angle measurement method, storage medium, and electronic device suitable for radar with arbitrary subarray architecture. Background Technology

[0002] Digital beamforming (DBF) is a technology that uses digital technology to achieve beamforming. It retains all the information of the antenna array element signals and can use advanced digital signal processing techniques to process the array signals, resulting in excellent beamforming performance. In modern radar systems, to enhance detection power and improve angle measurement accuracy, radar antennas typically contain hundreds or even tens of thousands of elements, making it difficult to employ digital beamforming methods at the element level. Usually, large arrays are divided into subarrays, with analog phase shifters used for beamforming within each subarray, and digital beamforming used between subarrays. This significantly reduces the number of receiving channels required, saving hardware costs.

[0003] However, due to limitations in the structure of T / R components and power divider networks, antenna arrays often cannot be arbitrarily divided into subarrays in practice, especially large two-dimensional area arrays. Therefore, it is not advisable to improve beam performance solely by optimizing the subarray division method. Many phased array radars use monopulse angle measurement technology, which requires the simultaneous formation of sum and difference beams. During subarray simulation and synthesis, there is only one power divider network, making it impossible to simultaneously form sum and difference beams for angle measurement using amplitude weighting during full array element processing. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides an angle measurement method, storage medium, and electronic device suitable for radars with arbitrary subarray architectures, solving the technical problem of antenna design limitations on subarray partitioning.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An angle measurement method applicable to radars with arbitrary subarray architecture, comprising:

[0009] Based on the task requirements, the array is divided into several subarrays, and subarray-level beamforming is performed to construct the subarray echo signal vector model.

[0010] Based on the partitioned subarray structure, the phase center of the subarray is estimated using the calibration signal inversion method;

[0011] Construct the phase vector of the subarray echo signal, and construct the subarray phase gradient vector in combination with the subarray phase center;

[0012] The spacing between the phase centers of adjacent subarrays is calculated to construct the subarray gain normalization vector, and the phase gradient centroid is estimated using the weighted phase gradient method to obtain the target angle measurement results.

[0013] Preferably, based on task requirements, the N linearly uniformly distributed array elements are divided into M subarrays, N m Let m be the number of array elements contained in the m-th subarray. The process of performing subarray-level beamforming to construct a subarray echo signal vector model includes:

[0014] Model the radar echo signal of N linearly uniformly distributed array elements as follows: Where d is the element spacing, λ is the radar operating wavelength, and θ t Let be the angle of incidence of the target, the subscript t indicates that the angle corresponds to the target, e is the natural constant, sin is the sine function, j is the imaginary unit, and the superscript T indicates transpose;

[0015] Synthesize the echo signal of the m-th subarray Where the subscripts m,k correspond to the k-th element of the m-th subarray, and the element indices in the entire array are... w m,k s is the amplitude weighting value for this array element. m,k For the echo signal of this array element, a m,k The subarray synthesis guide vector is, which is The I in m,k elements, θ b The angle at which the synthesized beam points to the center is indicated by the subscript b, which indicates that the angle corresponds to the beam center angle.

[0016] The synthesized signals of each subarray are constructed as signal vectors to build the subarray echo signal vector model X = [x1,...,x...]. m ,...,x M ] T .

[0017] Preferably, the subarray phase center is estimated using the calibration signal inversion method based on the partitioned subarray structure, including:

[0018] Definition from Angle calibration signal The subscript 'c' indicates that the angle is the calibration signal angle;

[0019] Subarray synthesis is performed based on the partitioned subarray structure to obtain the subarray synthesis result of the calibration signal. Where e m,k For the I m,k The calibration signal received by each array element is the I-th value of the calibration signal E. m,k One element;

[0020] Estimate the phase center of each subarray Where φ c =angle(y' m ) represents the calibration signal y' received by the m-th subarray. m The phase value, where angle represents the phase of the signal;

[0021] Repeat the above operation for P calibration signals at different angles to obtain... in The position vector of the phase center of the m-th subarray is estimated from P calibration signals at different angles.

[0022] Preferably, the step of constructing the phase vector of the subarray echo signal and constructing the subarray phase gradient vector in combination with the subarray phase center includes:

[0023] The phase vector Φ of the subarray echo signal is constructed as Φ = [angle(x1), angle(x2), ..., angle(x... M )] T ;

[0024] Constructing the phase gradient vector in Let be the phase gradient of the m-th subarray.

[0025] Preferably, the subarray gain normalized vector is represented as follows: in is the normalized gain coefficient of the m-th subarray.

[0026] Preferably, the step of estimating the phase gradient centroid using the weighted phase gradient method to obtain the target angle measurement result includes:

[0027] Estimating the centroid of the phase gradient Where ||·||1 is the first norm;

[0028] Obtain target angle measurement results Where arcsin is the arcsine function.

[0029] An angle measurement system suitable for radar with arbitrary subarray architecture, comprising:

[0030] The subarray echo signal vector model construction module is used to divide the subarray into several subarrays based on task requirements and perform subarray-level beamforming to construct the subarray echo signal vector model.

[0031] The subarray phase center estimation module is used to estimate the subarray phase center based on the partitioned subarray structure and by using the calibration signal inversion method.

[0032] The subarray phase gradient vector construction module is used to construct the phase vector of the subarray echo signal and construct the subarray phase gradient vector in combination with the subarray phase center;

[0033] The target angle measurement result acquisition module is used to calculate the distance between the phase centers of adjacent subarrays to construct the subarray gain normalization vector, and to estimate the phase gradient centroid using the weighted phase gradient method to obtain the target angle measurement result.

[0034] A storage medium storing a computer program for angle measurement applicable to radar with arbitrary subarray architecture, wherein the computer program causes a computer to execute the angle measurement method applicable to radar with arbitrary subarray architecture as described above.

[0035] An electronic device, comprising:

[0036] One or more processors; a memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including an angle measurement method applicable to an arbitrary subarray radar as described above.

[0037] (III) Beneficial Effects

[0038] This invention provides an angle measurement method, storage medium, and electronic device suitable for radars with arbitrary subarray architectures. Compared with existing technologies, it has the following advantages:

[0039] In this invention, the system first divides the array into several subarrays based on mission requirements and performs subarray-level beamforming to construct a subarray echo signal vector model. Secondly, it uses a calibration signal inversion method to estimate the subarray phase center. Thirdly, it constructs the subarray phase gradient vector. Finally, it uses a weighted phase gradient method to estimate the phase gradient centroid to obtain the target angle measurement result. This method uses the phase gradient as the basis for angle measurement. By normalizing the phase difference between adjacent subarrays through the spacing between them, the phase difference between different subarray spacings is only related to the target angle and is independent of the subarray length. Therefore, it can be applied to radar antenna arrays with arbitrary subarray divisions, reducing antenna design limitations. Furthermore, the subarray synthesis further reduces the computational scale and improves the system's real-time computing performance. Attached Figure Description

[0040] 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 these drawings without creative effort.

[0041] Figure 1A flowchart illustrating an angle measurement method applicable to radar with arbitrary subarray architecture, provided by an embodiment of the present invention;

[0042] Figure 2 The radiation patterns of the full array and subarrays provided in the embodiments of the present invention;

[0043] Figure 3 This is a schematic diagram of the subarray phase center provided in an embodiment of the present invention;

[0044] Figure 4 This is a comparison chart of angle measurement error results for targets at different angles, provided in an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] This application provides an angle measurement method, storage medium, and electronic device suitable for radar with arbitrary subarray architecture, thus solving the technical problem of antenna design limiting subarray division.

[0047] The technical solution in this application embodiment is to solve the above-mentioned technical problems, and the core technical improvement is as follows:

[0048] This invention employs phase gradient as the basis for angle measurement. It normalizes the phase difference between subarrays through subarray spacing, ensuring that the phase difference between different subarray spacings depends only on the target angle and is independent of the subarray length. Therefore, angle measurement using phase gradient is applicable to radar antenna arrays with arbitrary subarray divisions, reducing antenna design limitations. Furthermore, this invention further reduces the computational scale by synthesizing subarrays, improving the system's real-time computing performance.

[0049] The phase value is a parameter corresponding to the wavelength. The phase gradient method normalizes the phase using the subarray spacing, which requires high accuracy for the subarray spacing. In order to achieve high-precision estimation of the subarray spacing, this embodiment of the invention uses the calibration signal inversion method. The subarray spacing is inverted and calculated using a series of calibration signals at different angles. Then, the phase center estimate of the subarray is obtained by combining the inversion results of multiple calibration signals.

[0050] Furthermore, considering the differences in signal quality obtained with different subarray lengths, directly calculating the mean is easily affected by estimates with poor signal quality. Therefore, this embodiment of the invention also normalizes the subarray gain and calculates the centroid after weighting the phase gradient of the subarray to ensure robustness in angle measurement.

[0051] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0052] Example 1:

[0053] like Figure 1 As shown, this embodiment of the invention provides an angle measurement method applicable to radars with arbitrary subarray architectures, including:

[0054] S1. Based on the task requirements, divide the array into several subarrays and perform subarray-level beamforming to construct the subarray echo signal vector model.

[0055] S2. Based on the partitioned subarray structure, the phase center of the subarray is estimated using the calibration signal inversion method;

[0056] S3. Construct the phase vector of the subarray echo signal, and construct the subarray phase gradient vector in combination with the subarray phase center;

[0057] S4. Calculate the distance between the phase centers of adjacent subarrays to construct the subarray gain normalization vector, and use the weighted phase gradient method to estimate the phase gradient centroid to obtain the target angle measurement result.

[0058] The embodiments of the present invention utilize synthesized subarrays to reduce system complexity, adapt arbitrary subarray partitioning architecture through subarray phase center estimation, and achieve angle measurement through phase gradient method, thereby reducing the requirement for uniform partitioning of antenna elements when synthesizing radar system subarrays.

[0059] The following sections will detail each step of this method with specific examples:

[0060] In step S1, based on the task requirements, the system is divided into several subarrays, and subarray-level beamforming is performed to construct the subarray echo signal vector model. The relevant steps are as follows:

[0061] S11. Based on task requirements, divide the N linearly uniformly distributed array elements into M subarrays, N m Let m be the number of array elements contained in the m-th subarray.

[0062] For example, in this embodiment of the invention, the antenna consists of N = 64 antenna elements, with an element spacing of d = 0.05 m and an operating wavelength of λ = 0.1 m. The antenna elements are divided into M = 8 subarrays, with each subarray containing N elements. mThe numbers are 4, 8, 8, 12, 8, 12, 4, 8.

[0063] S12. Model the radar echo signal of N linearly uniformly distributed array elements as... Where d is the element spacing, λ is the radar operating wavelength, and θ t Let be the angle of incidence of the target, the subscript t indicates that the angle corresponds to the target, e is the natural constant, sin is the sine function, j is the imaginary unit, and the superscript T indicates transpose.

[0064] S13. Synthesize the echo signal of the m-th subarray. Where the subscripts m,k correspond to the k-th element of the m-th subarray, and the element indices in the entire array are... w m,k s is the amplitude weighting value for this array element. m,k For the echo signal of this array element, a m,k The subarray synthesis guide vector is, which is The I in m,k elements, θ b The angle at which the synthesized beam points to the center is indicated by the subscript b, which indicates that the angle corresponds to the beam center angle.

[0065] Continuing with the above example, this embodiment of the invention specifically uses a Taylor window amplitude weight with a sidelobe level of -40dB. The synthesized beam pointing towards the center angle θ b =45°. For example... Figure 2 As shown, Figure 2 The images show the beam patterns of the entire array and its eight subarrays. Different subarray widths correspond to different main lobe widths.

[0066] S14. Construct the composite signal of each subarray into a signal vector form to build the subarray echo signal vector model X = [x1,...,x] m ,...,x M ] T .

[0067] In step S2, based on the divided subarray structure, the phase center of the subarray is estimated using the calibration signal inversion method. The relevant steps are as follows:

[0068] S21, Definition from Angle calibration signal The subscript 'c' indicates that the angle is the calibration signal angle.

[0069] S22. Based on the subarray structure divided in S1, perform subarray synthesis to obtain the subarray synthesis result of the calibration signal. Where e m,k For the I m,k The calibration signal received by each array element is the I-th value of the calibration signal E. m,k Each element.

[0070] S23. Estimate the phase center of each subarray. Where φ c =angle(y' m ) represents the calibration signal y' received by the m-th subarray. m The phase value, angle represents the phase of the signal.

[0071] S24. Repeat the operations of S21 to S23 above for P calibration signals at different angles to obtain... in The position vector of the phase center of the m-th subarray is estimated from P calibration signals at different angles.

[0072] Continuing with the above example, in this embodiment of the invention, P is set to 7, and the calibration signal angles are 44.1000, 44.4000, 44.7000, 45.0000, 45.3000, 45.6000, and 45.900 degrees. Array element signals are generated using the aforementioned calibration signals, and then subarray echo signals are generated by combining a beamforming vector with a beam center of 45 degrees and a weighted vector. The phase of each subarray at each angle is obtained. Using the subarray phase and the target angle, the phase center position of the subarray is inverted to obtain: 0.1303, 0.4573, 0.8438, 1.3396, 1.8207, 2.2890, 2.7180, and 2.9937 meters. Figure 3 As shown, Figure 3 This example shows the relative positional distribution of the phase center and array elements.

[0073] In step S3, the phase vector of the subarray echo signal is constructed, and the subarray phase gradient vector is constructed in conjunction with the subarray phase center. The relevant steps are as follows:

[0074] S31. Construct the phase vector Φ of the subarray echo signal = [angle(x1), angle(x2), ..., angle(x...] M )] T .

[0075] S32. Construct the phase gradient vector in Let be the phase gradient of the m-th subarray.

[0076] In step S4, the spacing between the phase centers of adjacent subarrays is calculated to construct the subarray gain normalization vector, and the phase gradient centroid is estimated using the weighted phase gradient method to obtain the target angle measurement result. The relevant steps are as follows:

[0077] S41. Construct the subarray gain normalization weight vector. in is the normalized gain coefficient of the m-th subarray.

[0078] Continuing with the example above, here f m The values ​​are 6.3033, 8.7979, 14.4901, 13.6360, 12.9237, 10.8410, and 4.4792, respectively.

[0079] S42. Estimating the phase gradient centroid Where ||·||1 is the first norm.

[0080] S43. Obtain the target angle measurement result. Where arcsin is the arcsine function.

[0081] Continuing with the example above, after generating target element echoes at different angles from 43.5 degrees to 46.5 degrees, subarray synthesis with a beam center of 45 degrees is performed for each echo angle. The phase values ​​of each subarray are then combined with the phase center to construct the phase gradient, and the angle measurement result is obtained by weighting the subarray gains. For example... Figure 4 As shown, Figure 4 This shows the error distribution of the angle measurement results in this example. It can be seen that when directly using the subarray phase center for angle measurement, the target angle measurement deviation exceeds ±0.1° for different angles, while when using the subarray phase center obtained by this method for angle measurement, the target angle measurement deviation for different angles is ±0.01°. That is, it has better performance for target angle measurement at different angles.

[0082] Thus, this embodiment of the invention completes the entire process of an angle measurement method applicable to radar with arbitrary subarray architecture.

[0083] Example 2:

[0084] This invention provides an angle measurement system suitable for radars with arbitrary subarray architecture, comprising:

[0085] The subarray echo signal vector model construction module is used to divide the subarray into several subarrays based on task requirements and perform subarray-level beamforming to construct the subarray echo signal vector model.

[0086] The subarray phase center estimation module is used to estimate the subarray phase center based on the partitioned subarray structure and by using the calibration signal inversion method.

[0087] The subarray phase gradient vector construction module is used to construct the phase vector of the subarray echo signal and construct the subarray phase gradient vector in combination with the subarray phase center;

[0088] The target angle measurement result acquisition module is used to calculate the distance between the phase centers of adjacent subarrays to construct the subarray gain normalization vector, and to estimate the phase gradient centroid using the weighted phase gradient method to obtain the target angle measurement result.

[0089] Example 3:

[0090] This invention provides a storage medium storing a computer program for angle measurement applicable to radar with arbitrary subarray architecture, wherein the computer program causes a computer to execute the angle measurement method applicable to radar with arbitrary subarray architecture as described in Embodiment 1.

[0091] Example 4:

[0092] This invention provides an electronic device, comprising:

[0093] One or more processors; a memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including an angle measurement method for performing an arbitrary subarray radar as described in Embodiment 1.

[0094] It is understood that the angle measurement system, storage medium, and electronic device provided in the embodiments of the present invention for radar with arbitrary subarray architecture correspond to the angle measurement method provided in the embodiments of the present invention for radar with arbitrary subarray architecture. The explanations, examples, and beneficial effects of the relevant contents can be referred to the corresponding parts of the angle measurement method, and will not be repeated here.

[0095] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0096] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of angle measurement suitable for any subarray architecture radar, characterized in that, include: Based on the task requirements, the array is divided into several subarrays, and subarray-level beamforming is performed to construct the subarray echo signal vector model. Based on the partitioned subarray structure, the phase center of the subarray is estimated using the calibration signal inversion method; Construct the phase vector of the subarray echo signal, and construct the subarray phase gradient vector in combination with the subarray phase center; The spacing between the phase centers of adjacent subarrays is calculated to construct the subarray gain normalization vector, and the phase gradient centroid is estimated by the weighted phase gradient method to obtain the target angle measurement result; Based on the task requirements, N linearly uniformly distributed array elements are divided into M subarrays. For the first The number of array elements contained in each subarray. The subarray-based subarray structure, using the calibration signal inversion method to estimate the subarray phase center, includes: Definition from Angle calibration signal subscript This indicates that the angle is the calibration signal angle. For the spacing between array elements, For radar operating wavelength, e is a natural constant, and sin is the sine function. j The unit is the imaginary unit, and the superscript T indicates transpose; Subarray synthesis is performed based on the partitioned subarray structure to obtain the subarray synthesis result of the calibration signal. subscript Corresponding to the The first of the sub-arrays There are one array element, and the array element sequence number in the entire array is... ; For the first The calibration signal received by each array element has a value that is the calibration signal. The One element; This is the amplitude weighting value for the array element; The subarray synthesis guide vector is, which is The first in One element, The angle at which the synthesized beam points to the center is indicated by the subscript. This indicates that the beam pointing towards the center corresponds to the beam center angle; Estimate the phase center of each subarray ,in Indicates the first The calibration signal received by each subarray phase value, Indicates the phase of the signal; Repeat the above operation for P calibration signals at different angles to obtain... ,in The first value is obtained by estimating the calibration signals at P different angles. The phase center position vector of each subarray; The construction of the phase vector of the subarray echo signal, and the construction of the subarray phase gradient vector in combination with the subarray phase center, includes: Constructing the phase vector of the subarray echo signal ; Constructing the phase gradient vector ,in For the first The phase gradient of the subarray; The subarray gain normalization vector is represented as follows: ,in For the first Normalized gain coefficient of the subarray; The step of estimating the phase gradient centroid using the weighted phase gradient method to obtain the target angle measurement result includes: Estimating the centroid of the phase gradient ,in It is a norm; Obtain target angle measurement results ,in It is an arcsine function.

2. The angle measurement method applicable to radar with arbitrary subarray architecture as described in claim 1, characterized in that, The process of performing subarray-level beamforming to construct a subarray echo signal vector model includes: Model the radar echo signal of N linearly uniformly distributed array elements as follows: ,in The angle of incidence of the target, subscript t This indicates that the angle of incidence corresponds to the target; Synthesis of the first Individual array echo signal ,in For the first The first of the sub-arrays The echo signal of each array element; The synthesized signals of each subarray are constructed as signal vectors to build the subarray echo signal vector model. .

3. An angle measurement system suitable for radar with arbitrary subarray architecture, characterized in that, An angle measurement method for performing an arbitrary subarray radar as described in claim 1 includes: The subarray echo signal vector model construction module is used to divide the subarray into several subarrays based on task requirements and perform subarray-level beamforming to construct the subarray echo signal vector model. The subarray phase center estimation module is used to estimate the subarray phase center based on the partitioned subarray structure and by using the calibration signal inversion method. The subarray phase gradient vector construction module is used to construct the phase vector of the subarray echo signal and construct the subarray phase gradient vector in combination with the subarray phase center; The target angle measurement result acquisition module is used to calculate the distance between the phase centers of adjacent subarrays to construct the subarray gain normalization vector, and to estimate the phase gradient centroid using the weighted phase gradient method to obtain the target angle measurement result.

4. A storage medium, characterized in that, It stores a computer program for angle measurement applicable to radar with arbitrary subarray architecture, wherein the computer program causes a computer to execute the angle measurement method applicable to radar with arbitrary subarray architecture as described in claim 1 or 2.

5. An electronic device, characterized in that, include: One or more processors; Memory; And one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including an angle measurement method for an arbitrary subarray radar as described in claim 1 or 2.

Images