An angle measurement method, device and equipment based on four-channel array synthetic multi-beam and a medium

Abstract

The present application relates to the field of azimuth measurement, and in particular to a kind of angle measurement method, device, equipment and medium based on four-channel array synthesis multi-beam.The four-way original baseband complex signal is reconstructed by adjacent channel complex domain coherent weighting superposition to expand the number of full-space direction-finding beam to eight-way;Through the closed-loop adaptive amplitude equalization processing based on amplitude difference margin, the amplitude of composite beam is dynamically adjusted, so that the amplitude of composite beam is always lower than the amplitude of original beam in amplitude domain and remains within the preset amplitude difference range;The beam channel number corresponding to the two values with the maximum amplitude in the eight-way beam and the difference value between the two values are extracted to construct a three-dimensional coupled feature vector, the channel number is used to complete the angle domain interval discrimination, and the difference value is used to complete the accurate positioning in the interval;Different working frequency points are respectively used to participate in composite beam reconstruction using corresponding pre-calibrated complex weighting coefficients, which improves the reliability of full-space angle measurement.

Description

Technical Field

[0001] This invention relates to the field of orientation measurement, and specifically to an angle measurement method, apparatus, device, and medium based on a four-channel array synthesized multibeam. Background Technology

[0002] The TCAS (Traffic Collision Avoidance System) is a core airborne device for preventing dangerous approach and collisions between aircraft in mid-air. It can operate independently of the ground air traffic control system. Utilizing a 1030 / 1090MHz interrogation-response mechanism, the system acquires information such as the distance, altitude, and orientation of nearby intruding aircraft, performs conflict detection, traffic alerts, and collision avoidance commands, and guides pilots to take evasive maneuvers. It is a key technological means to ensure flight safety and prevent mid-air collisions.

[0003] Azimuth measurement is a core component of TCAS target situation display. The accuracy of angle measurement directly determines the accuracy of the target azimuth calculation results, which is a crucial foundation for ensuring a realistic situational view and stable target tracking. If the discrete error threshold of angle estimation exceeds the limit, it will induce target azimuth jumps and threat area discrimination shifts, significantly reducing the reliability of the crew's situational awareness and seriously affecting the flight operation experience.

[0004] Existing mature TCAS azimuth estimation architectures generally employ a four-element square planar array + four-beam single-dimensional amplitude comparison angle measurement architecture, relying on the difference in RF amplitude between the main beam and adjacent beams to match an offline OBA offset calibration table to complete the arrival angle fitting calculation. However, the four-beam amplitude comparison algorithm has strict boundary constraints on the consistency of array unit radiation pattern amplitude. Array manufacturing tolerances, assembly positioning deviations, and RF channel consistency can all cause non-consistent distortion of the radiation pattern gain curves of array units in the same batch or across batches. The global OBA calibration table generated by the unified reference array calibration cannot be adapted to all individual array hardware. The experimentally measured extreme angle error of some arrays can reach 20°, making the angle measurement accuracy unable to meet the system design requirements. Summary of the Invention

[0005] The purpose of this invention is to provide an angle measurement method, device, equipment, and medium based on a four-channel array synthesized multibeam, which solves the problems in the prior art.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, embodiments of the present invention provide an angle measurement method based on a four-channel array synthesized multibeam, comprising:

[0008] The target radio frequency signal received by the four-element antenna array is down-converted and quadrature demodulated to obtain four native baseband complex signals and the first amplitude value of each native baseband complex signal.

[0009] Based on the original baseband complex signal and the pre-calibrated complex weighting coefficients corresponding to the current operating frequency, the original baseband complex signals of adjacent channels are coherently weighted and superimposed in the complex domain to obtain four composite baseband signals and the second amplitude value of each composite baseband signal. The complex weighting coefficients are pre-solved based on the full spatial scanning data with the optimization objectives of minimizing the smoothness of the composite beam pattern and the global angle measurement error.

[0010] Based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value in the same angular domain, amplitude equalization processing is performed on each second amplitude value to obtain the balanced second amplitude values ​​of the four channels.

[0011] Construct a three-dimensional coupling feature vector by taking the beam channel numbers corresponding to the two largest values ​​in the set of all first amplitude values ​​and all equalized second amplitude values, and the difference between the two values.

[0012] The estimated azimuth angle of the target wave is obtained by traversing and matching the three-dimensional coupled feature vector and the pre-constructed angle mapping database at the current operating frequency. The angle mapping database is pre-constructed based on the eight-beam amplitude domain data of the full-space sweep of the reference array. Each standard sample in the angle mapping database contains a standard three-dimensional feature vector and its corresponding theoretical azimuth angle.

[0013] Preferably, the step of performing amplitude equalization processing on each second amplitude value based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value within the same angular domain to obtain four-channel equalized second amplitude values ​​includes:

[0014] The first amplitude value and the second amplitude value are dB domain amplitude observation values ​​obtained after performing dB domain conversion on the modulus of the baseband complex signal;

[0015] For any composite baseband signal generated by the coherent superposition of the native baseband complex signals of two adjacent channels, the angular domain range defined by the two adjacent channels constituting the composite baseband signal is determined as the current angular domain range of the composite baseband signal.

[0016] Select the first amplitude value that is within the current angular domain range and has the largest amplitude value from the four first amplitude values ​​as the reference amplitude value;

[0017] The dB-domain difference calculation is performed between the reference amplitude value and the maximum value among the four second amplitude values ​​to obtain the amplitude difference margin.

[0018] Based on the comparison result between the amplitude difference margin and the preset amplitude constraint threshold, the adaptive equalization attenuation factor is updated in a closed-loop iterative manner.

[0019] In the dB domain, the updated adaptive equalization attenuation factor is subtracted from the four second amplitude values ​​to obtain the four equalized second amplitude values.

[0020] Preferably, updating the adaptive equalization attenuation factor according to a closed-loop iterative method based on the comparison result between the amplitude difference margin and the preset amplitude constraint threshold includes:

[0021] The initial value of the adaptive equalization attenuation factor is set to a preset fixed value;

[0022] When the amplitude difference margin is less than the preset amplitude constraint threshold, it is determined that the composite beam gain is too high, and the adaptive equalization attenuation factor is increased by a preset step size.

[0023] When the amplitude difference margin is greater than the sum of the preset amplitude constraint threshold and the preset amplitude redundancy threshold, it is determined that the equalization attenuation is excessive, and the adaptive equalization attenuation factor is reduced by a preset step size.

[0024] When the amplitude difference margin is greater than or equal to the preset amplitude constraint threshold and less than or equal to the sum of the preset amplitude constraint threshold and the preset amplitude redundancy threshold, the adaptive equalization attenuation factor remains unchanged.

[0025] Preferably, the method further includes:

[0026] Set the upper and lower limits of the adaptive equalization attenuation factor;

[0027] After each update of the adaptive equalization attenuation factor, it is determined whether the updated adaptive equalization attenuation factor exceeds the upper limit value or the lower limit value.

[0028] If the updated adaptive equalization attenuation factor is greater than the upper limit value, then the adaptive equalization attenuation factor is limited to the upper limit value;

[0029] If the updated adaptive equalization attenuation factor is less than the lower limit value, then the adaptive equalization attenuation factor is limited to the lower limit value.

[0030] Preferably, the angle mapping database includes a first sample set independently constructed for the 1030MHz frequency point and a second sample set independently constructed for the 1090MHz frequency point; according to the current working frequency point, standard samples of the corresponding frequency point are selected from the first sample set or the second sample set to participate in the traversal matching.

[0031] Preferably, the step of performing traversal matching based on the three-dimensional coupling feature vector and a pre-constructed angle mapping database at the current operating frequency to obtain the target arrival azimuth angle includes:

[0032] A weighted Euclidean distance similarity matching algorithm is adopted. According to the preset peak index dimension weight, sub-peak index dimension weight, and amplitude difference dimension weight, the weighted Euclidean distance value between the three-dimensional coupled feature vector and the standard three-dimensional feature vector contained in each standard sample in the angle mapping database is calculated, and the weighted Euclidean distance value is used as the similarity value.

[0033] Traverse all storage units of the angle mapping database and select the standard sample with the smallest weighted Euclidean distance value;

[0034] The theoretical azimuth angle bound to the selected standard sample is extracted as the estimated result of the target wave azimuth angle.

[0035] Preferably, the method further includes:

[0036] The target's azimuth angle, slant range information, and altitude information are fused to reconstruct the target's spatial coordinates.

[0037] The reconstructed target spatial coordinates are then fed into the Kalman track filtering module for continuous and stable track tracking.

[0038] Secondly, embodiments of the present invention provide an angle measuring device based on a four-channel array synthesized multibeam, comprising:

[0039] The receiving and processing module is used to perform down-conversion and quadrature demodulation on the target radio frequency signal received by the four-element antenna array to obtain four native baseband complex signals and the first amplitude value of each native baseband complex signal.

[0040] The superposition module is used to perform complex domain coherent weighted superposition of the original baseband complex signals of adjacent channels based on the original baseband complex signals and the pre-calibrated complex weighting coefficients corresponding to the current operating frequency, to obtain four composite baseband signals and a second amplitude value of each composite baseband signal. The complex weighting coefficients are pre-solved based on full-space scanning data with the optimization objectives of minimizing the smoothness of the composite beam pattern and the global angle measurement error.

[0041] The equalization processing module is used to perform amplitude equalization processing on each second amplitude value based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value in the same angular domain, so as to obtain the equalized second amplitude values ​​of the four channels.

[0042] The module is used to construct a three-dimensional coupling feature vector by taking the beam channel number corresponding to the two largest values ​​in the set of all first amplitude values ​​and all equalized second amplitude values ​​and the difference between the two values.

[0043] The traversal matching module is used to perform traversal matching based on the three-dimensional coupled feature vector and the pre-constructed angle mapping database at the current operating frequency to obtain the estimated result of the target arrival azimuth angle. The angle mapping database is pre-constructed based on the eight-beam amplitude domain data of the full-space scanning of the reference array. Each standard sample in the angle mapping database contains a standard three-dimensional feature vector and its corresponding theoretical azimuth angle.

[0044] Thirdly, embodiments of the present invention provide an electronic device, including: at least one processor, at least one memory, and computer program instructions stored in the memory, which, when executed by the processor, implement the method of the first aspect described above.

[0045] Fourthly, embodiments of the present invention provide a storage medium storing computer program instructions, which, when executed by a processor, implement the method of the first aspect described above.

[0046] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0047] Without increasing antenna elements or RF channels, four native baseband complex signals are coherently weighted and superimposed in the complex domain of adjacent channels to reconstruct four composite beams, expanding the number of direction-finding beams in the entire spatial domain to eight, thereby increasing the angular domain sampling density. By performing closed-loop adaptive amplitude equalization based on amplitude difference margin on the composite beams, the composite beam amplitude remains lower than the native beam amplitude under dynamic conditions and stays within a preset amplitude difference range, avoiding amplitude aliasing caused by channel gain drift or signal strength changes. The beam channel numbers corresponding to the two largest amplitude values ​​among the eight beams and their difference are extracted to construct a three-dimensional coupling feature vector. The channel numbers are used to determine angular domain intervals, and the difference is used to achieve angle positioning within the interval, reducing the interference of single-dimensional amplitude disturbances on angle estimation. For the 1030MHz and 1090MHz dual-frequency points, corresponding complex weighting coefficients are pre-calibrated to participate in the composite beam reconstruction, eliminating the impact of antenna characteristic differences between frequency points on angle measurement consistency. Ultimately, this ensures that the angle estimation remains stable under individual differences in array hardware and channel amplitude and phase drift, thereby improving the reliability of full-space angle measurement. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0049] Figure 1 This is a flowchart illustrating the angle measurement method based on a four-channel array synthesized multibeam provided by the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0051] It should be noted that, in this document, relational terms such as "first" and "second" are used merely 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..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0052] It should be noted that all actions involving the acquisition of signals, information, or data in this invention are carried out in compliance with the relevant data protection laws and regulations of the locality and with authorization from the owner of the relevant device.

[0053] Example 1

[0054] Please see Figure 1 This invention provides an angle measurement method based on a four-channel array synthesized multibeam, comprising:

[0055] S1. Perform down-conversion and quadrature demodulation on the target RF signal received by the four-element antenna array to obtain four native baseband complex signals and the first amplitude value of each native baseband complex signal;

[0056] Among them, the four-element antenna array is a receiving array composed of four antenna elements arranged in a square geometric topology. The four elements are evenly distributed along the orthogonal reference angle domain, and each element corresponds to channels Ch1, Ch2, Ch3, and Ch4, respectively, for receiving 1030MHz interrogation signals and 1090MHz response signals in space.

[0057] Down-conversion and quadrature demodulation: The radio frequency signal received by the antenna is filtered and amplified, and then mixed with the local oscillator signal for down-conversion to an intermediate frequency signal; then the intermediate frequency signal is demodulated to obtain the original baseband complex signal.

[0058] The original baseband complex signal: The complex form of the baseband signal obtained after down-conversion and quadrature demodulation, where the real part is the in-phase component and the imaginary part is the quadrature component, is represented as follows. ,in Corresponding to four antenna channels respectively, this complex signal completely preserves the amplitude and phase information of the original radio frequency signal.

[0059] First amplitude value: for the original baseband complex signal Modulo value Then converted to dB domain The resulting dB-domain amplitude observations are transformed to map linear amplitudes to the logarithmic domain, enabling subsequent amplitude comparisons and difference operations to exhibit linear superposition properties in the logarithmic domain.

[0060] In step S1, each of the four antenna elements independently receives the target radio frequency signal in the spatial domain, performs down-conversion and quadrature demodulation through its respective radio frequency front-end, and synchronously outputs four native baseband complex signals. , , , The magnitude of each complex signal is calculated and converted in dB domain to obtain the first amplitude value of the four channels. , , , This serves as the original data reference for subsequent beam reconstruction and angle calculation. Simultaneous acquisition across four channels ensures that the phase relationship of the signals received from each channel at the same time is fully preserved, a prerequisite for subsequent complex-domain coherent superposition processing. After converting the amplitude to the dB domain, the amplitude difference calculation and attenuation equalization calculation in subsequent steps can be implemented in this logarithmic domain using simple addition and subtraction, avoiding the computational complexity caused by multiplication and division operations in the linear domain.

[0061] S2. Based on the original baseband complex signal and the pre-calibrated complex weighting coefficients corresponding to the current operating frequency, the original baseband complex signals of adjacent channels are coherently weighted and superimposed in the complex domain to obtain four composite baseband signals and the second amplitude value of each composite baseband signal. The complex weighting coefficients are pre-solved based on the full spatial scanning data with the optimization objectives of minimizing the smoothness of the composite beam pattern and the full-domain angle measurement error.

[0062] Among them, the complex weighting coefficient is a pre-calibrated complex multiplier used to jointly adjust the amplitude and phase of the native baseband complex signal. This coefficient is in complex form and has both amplitude scaling and phase rotation functions.

[0063] Current operating frequency: The radio frequency at which the TCAS system operates in real time, including two operating states: 1030MHz interrogation frequency and 1090MHz response frequency. The system automatically identifies and determines the current frequency based on the processing object of the current receiving channel.

[0064] Adjacent channels: In a square planar array, two adjacent channels in clockwise or counterclockwise order form four pairs of adjacent relationships: Ch1 ​​and Ch2, Ch2 and Ch3, Ch3 and Ch4, and Ch4 and Ch1.

[0065] Coherent weighted superposition in the complex domain: The original baseband complex signals of two adjacent channels are multiplied by the corresponding complex weighting coefficients and then complex addition is performed. Since the signals are in complex form, the phase of each signal is included in the operation during the superposition process. In-phase components are superimposed and enhanced, while quadrature components are canceled or retained, thereby achieving beam pointing shift and pattern reconstruction.

[0066] Composite baseband signal: A new complex signal generated by coherently weighted superposition of the original baseband complex signals from adjacent channels in the complex domain, denoted as... , , , ,in For the corresponding frequency point The complex weighting coefficients.

[0067] The second amplitude value is the dB domain amplitude observation value obtained after taking the modulus value of the composite baseband signal and performing dB domain conversion. It has the same physical dimensions and mathematical form as the first amplitude value and can be directly used in subsequent comparisons and difference calculations.

[0068] Full-space scan data: Eight-beam amplitude response data are collected in a standard test environment using a reference array and a standard RF channel as the hardware platform, with preset angle steps in the omnidirectional angle range from 0° to 360°. This data is used to solve for the optimal weighting coefficients and to construct an angle mapping database.

[0069] Composite beam pattern smoothness: a measure of the continuity of the amplitude response of a composite beam in the angular domain. The higher the pattern smoothness, the slower the amplitude change at adjacent angles, the smaller the depth of the beam crossover point, and the lower the sensitivity of the angle estimate to amplitude disturbances.

[0070] Global angle measurement error: The statistical value of the deviation between the estimated angle and the actual angle of arrival using the composite beam angle measurement method in the entire airspace. Minimizing this deviation is the optimization objective to achieve balanced angle measurement performance of the weighting coefficient across all azimuth angles.

[0071] In step S2, the optimal complex weighting coefficients are selected from the pre-calibrated dual-frequency reconstruction coefficient matrix based on the current operating frequency of the system. Weighted superposition operations are performed on the native baseband complex signals of four adjacent channels to generate four composite baseband signals. , , , The magnitude values ​​of the four composite baseband signals were calculated and converted in the dB domain to obtain the second amplitude values ​​of the four signals. , , , The four native beams and four composite beams together form an eight-beam array covering the entire 360° airspace, doubling the airspace sampling density compared to the native four beams. Independent weighting coefficients at both frequencies ensure that the optimal radiation patterns at 1030MHz and 1090MHz are matched, eliminating beam distortion caused by differences in antenna radiation characteristics during frequency switching.

[0072] In some possible implementations, the complex weighting coefficients are obtained in advance according to the following steps:

[0073] Four native baseband complex signals of a standard array at various angles are collected in the entire spatial domain by stepping at a fixed angle, and used as a full spatial domain scanning sample set;

[0074] The candidate complex weighting coefficients are substituted into the coherent weighted superposition formula of adjacent channels to calculate the four composite baseband signals. The modulus values ​​of each original baseband signal and composite baseband signal are taken and converted to the dB domain to obtain the eight-dimensional amplitude vector at each angle.

[0075] Based on the eight-beam amplitude response collected and statistically averaged by the same batch of standard reference arrays under the same test conditions, an ideal eight-dimensional amplitude vector is constructed at each angle. The weighted sum of squared Euclidean distances between the eight-dimensional amplitude vector and the ideal eight-dimensional amplitude vector is calculated in the entire spatial domain as the cost function of angle measurement error.

[0076] The sum of the first-order difference squares of the dB domain amplitude of each composite beam at adjacent angular positions is calculated in the entire spatial domain and used as the cost function for pattern smoothness.

[0077] The angle measurement error cost function and the direction pattern smoothness cost function are weighted and merged into a single cost function. The training set and the validation set are divided from the full-space scanning sample set by cross-validation. The weight value that minimizes the angle measurement error on the validation set is selected as the final value of the regularization weight coefficient in the single cost function.

[0078] With the constraint that the magnitude of the candidate complex weighting coefficient is no greater than 1, numerical optimization is performed at multiple initial points within the complex plane range that satisfies the constraint. The solution that minimizes the single cost function is selected as the optimal complex weighting coefficient for the current operating frequency. The above process is performed independently for the two operating frequencies of 1030MHz and 1090MHz to obtain the optimal complex weighting coefficients corresponding to the two frequencies and store them as a reconstruction coefficient matrix.

[0079] Specifically, during the pre-calibration phase, a standard four-element antenna array is installed on a microwave anechoic chamber turntable. Using a reference RF channel as the receiving link, a continuous wave test signal is generated by a signal source and radiated into space via a standard transmitting antenna. The turntable moves in fixed-angle steps. exist to Rotate across the entire airspace, stepping at each angular position. The native baseband complex signals received by the four antenna elements are simultaneously acquired at the location, denoted as... The above-mentioned full-space data acquisition was performed independently at the two operating frequencies of 1030MHz and 1090MHz to obtain the sample sets for each frequency.

[0080] Weighting coefficients of candidate complex numbers Substituting into the formula for coherent superposition of adjacent channels subscript Pick Four composite baseband signals were calculated. The modulus values ​​of the four native baseband signals and the four composite baseband signals were taken and subjected to dB-domain conversion to obtain eight amplitude observation values. This constitutes the eight-dimensional amplitude vector at that angle. .

[0081] Define an ideal eight-dimensional magnitude vector : Independent of the current candidate coefficient The calibration procedure determines that the eight-beam amplitude response, acquired and statistically averaged under the same test conditions as the standard reference array from the same batch as the array to be calibrated, is used as the theoretical amplitude reference for each angle. The angle measurement error cost function is defined as the eight-dimensional amplitude vector of each beam channel. With the ideal magnitude vector The sum of the squared weighted Euclidean distances between them over the entire airspace:

[0082] ;

[0083] in Preset weighting coefficients for each beam channel are used to balance the differences in the contribution of different beams to the angle measurement accuracy.

[0084] Define the pattern smoothness cost function as the sum of squares of the absolute values ​​of the first-order differences in the amplitude of the composite beam at adjacent angular positions:

[0085] ;

[0086] in, Indicates the weighting coefficient of the current candidate Under the action, by adjacent channels and The synthesized composite beam has the following characteristics in the direction of arrival: The measured value of the amplitude in the dB domain. This index directly constrains the rate of change of the composite beam amplitude in the angular domain; the smaller the first-order difference, the flatter the radiation pattern and the smoother the amplitude change at adjacent angles.

[0087] The two optimization objectives mentioned above are weighted and combined into a single cost function:

[0088] ;

[0089] In the pre-calibration phase, cross-validation is used to determine the regularization weight coefficients. The full-space scanning data is evenly divided into a training set and a validation set according to angles. Different angles are then used on the training set. Each value is optimized to select the one that minimizes the angle measurement error of the validation set. As the final value.

[0090] Set amplitude constraints for complex weighting coefficients To ensure that the contribution of adjacent channels in the composite beam does not become excessively dominant by a single channel, and to maintain the main lobe pointing of the composite beam within the angular domain between the two primary beams, multiple initial search points are selected in a gridded manner within a complex plane region that satisfies the amplitude constraints. Local numerical optimization based on gradient descent is then performed on each initial search point to select the point that satisfies the amplitude constraints. The solution that yields the minimum value is used as the optimal complex weighting coefficient for the current frequency. This multi-initial-value strategy is used to avoid local minima caused by the non-convexity of the cost function in the complex plane.

[0091] The above-described full-spatial-domain scan, ideal amplitude vector calibration, cost function construction, cross-validation parameter determination, and numerical optimization with multiple initial values ​​were independently performed on the two operating frequencies of 1030MHz and 1090MHz to obtain the optimal complex weighting coefficients for each frequency. and The reconstructed coefficient matrix is ​​stored in the system's non-volatile memory.

[0092] S3. Based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value in the same angular domain, perform amplitude equalization processing on each second amplitude value to obtain the equalized second amplitude values ​​of the four channels.

[0093] Among them, the preferred first amplitude value in the same angular domain is: for any composite beam, its main lobe points to the angular domain interval between two adjacent original beams that synthesize the composite beam, and the largest of the four first amplitude values ​​in the angular domain interval is selected as the reference amplitude value of the composite beam.

[0094] Amplitude Margin: Within the same angular domain, the difference between the reference amplitude value and the maximum value among the four secondary amplitude values ​​is determined by... The calculations show that the amplitude of the composite beam is relatively high or low compared to the amplitude of the original beam.

[0095] Amplitude equalization processing: The adaptive equalization attenuation factor is dynamically adjusted through a closed-loop iterative method to perform overall attenuation or enhancement of the four second amplitude values, so that the amplitude of the composite beam is always lower than the amplitude of the original beam in the same angular domain and remains within the preset amplitude domain constraint threshold.

[0096] Equalized second amplitude value: Original second amplitude value minus adaptive equalization attenuation factor The adjusted amplitude value obtained later is expressed as , , , This value is used to replace the original second magnitude value in subsequent feature extraction.

[0097] In step S3, the angular domain range of each composite beam is determined, which is the spatial interval defined by the two adjacent primary beams that synthesize the composite beam. Within this interval, the largest of the four first amplitude values ​​is selected as the reference amplitude value. .calculate ,like Below the preset range constraint threshold ,Will Increasing the step size results in greater attenuation of the composite beam; if Higher than ,Will Reducing the step size by one results in less composite beam attenuation; if lie in Within the range, maintain Unchanged. This closed-loop iterative mechanism ensures that the composite beam amplitude is adjusted in real time to be lower than the original main beam and within the preset amplitude difference range, guaranteeing the monotonic uniqueness of the eight-beam amplitude matching decision logic and eliminating the risk of lookup mismatch caused by amplitude aliasing.

[0098] In some embodiments, the step of performing amplitude equalization processing on each second amplitude value based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value within the same angular domain to obtain four-channel equalized second amplitude values ​​includes:

[0099] The first amplitude value and the second amplitude value are dB domain amplitude observation values ​​obtained after performing dB domain conversion on the modulus of the baseband complex signal;

[0100] For any composite baseband signal generated by the coherent superposition of the native baseband complex signals of two adjacent channels, the angular domain range defined by the two adjacent channels constituting the composite baseband signal is determined as the current angular domain range of the composite baseband signal.

[0101] Select the first amplitude value that is within the current angular domain range and has the largest amplitude value from the four first amplitude values ​​as the reference amplitude value;

[0102] The dB-domain difference calculation is performed between the reference amplitude value and the maximum value among the four second amplitude values ​​to obtain the amplitude difference margin.

[0103] Based on the comparison result between the amplitude difference margin and the preset amplitude constraint threshold, the adaptive equalization attenuation factor is updated in a closed-loop iterative manner.

[0104] In the dB domain, the updated adaptive equalization attenuation factor is subtracted from the four second amplitude values ​​to obtain the four equalized second amplitude values.

[0105] The current angular domain range is defined as follows: In a four-element square planar array, the four native beams are arranged in a clockwise or counterclockwise order. The main lobe pointing of two adjacent native beams divides the 360° full space into four consecutive angular domain intervals. Any composite baseband signal is generated by the coherent weighted superposition of the complex signals of the native baseband from two adjacent channels. Its main lobe pointing is located within the angular domain interval between the main lobe pointing of the two adjacent native beams, and this interval is determined as the current angular domain range of the aforementioned composite baseband signal.

[0106] Reference amplitude value: Within the angular domain corresponding to the current composite beam, all four native beams respond to incoming signals within this range. The amplitude values ​​of different native beams exhibit a monotonic increasing or decreasing relationship with the direction of arrival. The largest amplitude value within this angular domain is selected from the four initial amplitude values ​​as the reference amplitude value. , representing the energy intensity of the native beam with the strongest response in the current angular domain.

[0107] Preset range constraint threshold : A fixed threshold can be configured for the project, typically ranging from 3dB to 6dB. It is required that the dB domain amplitude of the four composite beams is lower than the amplitude of the native main beam in the same angular domain at any azimuth angle. This ensures that the native beam always maintains a clear dominant position relative to the composite beam in amplitude sequencing.

[0108] Specifically, the baseband equivalent gain of the four composite beams, after coherent weighted superposition in the complex domain, inherently increases. Without intervention, the amplitude of the composite beams may approach or even exceed that of the original primary beam in certain angular domains, thus determining the primary-secondary relationship between the original beams and the composite beams in the eight-beam amplitude ranking. For each composite beam, its current angular domain range is first determined, and within this range, the maximum value from the four primary amplitude values ​​is selected as the reference amplitude value. This ensures that the comparison reference is strictly limited to the same local angular domain. Calculation Later and Comparison, difference direction driven Iterate along the direction of error reduction to form a negative feedback closed loop. Subtract the second amplitude value from all four paths uniformly. The equalized second amplitude value is obtained so that the amplitude of the composite beam is continuously constrained under the original main beam in the entire space domain and the preset amplitude difference is maintained, thus eliminating the risk of amplitude aliasing.

[0109] In some implementations, updating the adaptive equalization attenuation factor according to a closed-loop iterative method based on the comparison result between the amplitude difference margin and the preset amplitude constraint threshold includes:

[0110] The initial value of the adaptive equalization attenuation factor is set to a preset fixed value;

[0111] When the amplitude difference margin is less than the preset amplitude constraint threshold, it is determined that the composite beam gain is too high, and the adaptive equalization attenuation factor is increased by a preset step size.

[0112] When the amplitude difference margin is greater than the sum of the preset amplitude constraint threshold and the preset amplitude redundancy threshold, it is determined that the equalization attenuation is excessive, and the adaptive equalization attenuation factor is reduced by a preset step size.

[0113] When the amplitude difference margin is greater than or equal to the preset amplitude constraint threshold and less than or equal to the sum of the preset amplitude constraint threshold and the preset amplitude redundancy threshold, the adaptive equalization attenuation factor remains unchanged.

[0114] Among them, adaptive equilibrium attenuation factor This is a real-time adjustable amplitude attenuation parameter, measured in dB, used to uniformly attenuate the amplitudes of the four composite beams. Before the initial amplitude equalization process, It has not undergone any iterative updates and needs to be assigned a preset fixed value. As the initial state, the amplitude of the composite beam is made to be below the amplitude of the original main beam in the same angular domain at the initial moment, and the amplitude difference is close to the constraint threshold, so as to shorten the convergence time of subsequent closed-loop iterations.

[0115] Preset step size : For each iteration update This is a fixed adjustment amount, measured in dB. The step size must strike a balance between convergence speed and steady-state accuracy: an excessively large step size may lead to… It oscillates back and forth around the threshold and cannot be stable. If the step size is too small, the convergence is slow and it cannot quickly follow the channel gain drift.

[0116] Specifically, the RF channel gain drifts with temperature, device aging, and signal strength changes. A fixed attenuation factor cannot adapt to this drift, and the amplitude difference between the composite beam and the original main beam will continuously deviate from the preset threshold, entering the aliasing region or the excessive attenuation region. This embodiment compares the gain within each update cycle. and and Relationship-driven Closed-loop update: when the magnitude difference margin is below the lower limit, it increments positively; when it is above the upper limit, it increments negatively; and when it falls into the stable range, it remains unchanged. This three-branch update strategy enables... The automatic convergence process aims to stabilize the amplitude margin within a suitable value within the steady-state range. The hysteresis effect eliminates boundary oscillations. This closed-loop mechanism keeps the relative amplitude of the composite beam and the original beam constant across the entire operating range, without the need for manual intervention or offline recalibration.

[0117] In some embodiments, the method further includes:

[0118] Set the upper and lower limits of the adaptive equalization attenuation factor;

[0119] After each update of the adaptive equalization attenuation factor, it is determined whether the updated adaptive equalization attenuation factor exceeds the upper limit value or the lower limit value.

[0120] If the updated adaptive equalization attenuation factor is greater than the upper limit value, then the adaptive equalization attenuation factor is limited to the upper limit value;

[0121] If the updated adaptive equalization attenuation factor is less than the lower limit value, then the adaptive equalization attenuation factor is limited to the lower limit value.

[0122] Specifically, by setting and Two boundary values, in each After the update, a limit judgment will be performed: if Forced ;like Forced If the updated value is within the upper or lower limit, it remains unchanged. The value is determined based on the receiver noise floor of the composite beam channel to ensure that the amplitude of the attenuated composite beam is at least higher than the noise floor by a certain margin. The value of this value is determined based on the amplitude safety margin of the composite beam relative to the original beam, ensuring that the amplitude of the composite beam will not threaten the dominance of the original beam in any angular domain. This amplitude limiting protection mechanism provides a safety boundary for closed-loop iteration, preventing the system from entering a runaway state under extreme conditions and ensuring... It is constrained to the effective working range under all conditions.

[0123] S4. Construct a three-dimensional coupling feature vector by taking the beam channel numbers corresponding to the two largest values ​​in the set of all first amplitude values ​​and all equalized second amplitude values ​​and the difference between the two values.

[0124] Among them, the beam channel number is an index identifier that uniformly encodes the eight direction-finding beams. The original beams use numbers 1 to 4 to correspond to Ch1 to Ch4 respectively, and the composite beams use numbers 12, 23, 34, and 41 to correspond to the four composite beams respectively. This number uniquely identifies the spatial pointing position of each beam.

[0125] 3D Coupled Feature Vector: A combined vector consisting of three-dimensional features. ,in The beam channel number is the one with the maximum amplitude. The beam channel number is the second largest amplitude value. This represents the dB difference between the maximum amplitude value and the second largest amplitude value.

[0126] In step S4, the first amplitude value of the four channels is... With the second amplitude value of the four-way equalization Eight amplitude values ​​were collected into a set to be sorted. This set was then sorted in descending order to obtain an ordered arrangement from largest to smallest. The beam channel number corresponding to the first value after sorting was extracted as the peak beam index. The second-ranked beam channel number after sorting is extracted as the sub-peak beam index. Perform dB-domain difference calculation on the amplitude values ​​of the first and second positions after sorting. This yields the amplitude difference characteristics that characterize the degree to which the incoming wave deviates from the center beam. , , Combined into a three-dimensional coupled feature vector This three-dimensional feature utilizes both beam spatial distribution information and amplitude relative difference information, giving it a stronger resistance to amplitude disturbances compared to traditional single amplitude ratio features.

[0127] S5. Based on the three-dimensional coupling feature vector and the pre-constructed angle mapping database at the current operating frequency, a traversal matching is performed to obtain the estimated result of the target arrival azimuth angle. The angle mapping database is pre-constructed based on the eight-beam amplitude domain data of the full-space scanning of the reference array. Each standard sample in the angle mapping database contains a standard three-dimensional feature vector and its corresponding theoretical azimuth angle.

[0128] Among them, the angle mapping database: based on the reference array, the scanning is carried out in the entire spatial range with a preset angle step. The eight-channel amplitude data collected at each incoming wave angle are organized into a standard sample set in the form of three-dimensional coupled feature vectors. Each sample contains a standard three-dimensional feature vector and its corresponding theoretical azimuth angle. Independent datasets are constructed according to two working frequencies of 1030MHz and 1090MHz.

[0129] Standard Sample: The basic storage unit in the angle mapping database, containing two fields: the standard three-dimensional feature vector and the theoretical azimuth angle corresponding to that feature vector.

[0130] Traversal matching: The measured 3D coupled feature vector is compared one by one with all standard samples in the database. The similarity cost between each standard sample and the measured feature is calculated. The sample with the smallest cost value is found by comparing all samples.

[0131] In step S5, the corresponding angle mapping database is selected based on the system's current operating frequency, and the measured three-dimensional coupled feature vector is... As input for the query. For each standard sample in the database. The weighted Euclidean distance cost between the measured and actual features is calculated. After traversing all samples in the database, the standard sample with the lowest cost is selected. The theoretical azimuth angle bound to this standard sample is extracted and output as the estimated azimuth angle of the current target wave. Independent databases are constructed for each frequency point, coupled with adaptive weighting, ensuring that angle matching at each working frequency point uses a standard feature set consistent with the beam characteristics of that frequency point, avoiding matching deviations caused by differences in beam patterns between the two frequencies.

[0132] In some implementations, the angle mapping database includes a first sample set independently constructed for the 1030MHz frequency point and a second sample set independently constructed for the 1090MHz frequency point; according to the current operating frequency point, standard samples of the corresponding frequency point are selected from the first sample set or the second sample set to participate in the traversal matching.

[0133] In some implementations, the step of performing traversal matching based on the three-dimensional coupling feature vector and a pre-constructed angle mapping database at the current operating frequency to obtain the target arrival azimuth angle includes:

[0134] A weighted Euclidean distance similarity matching algorithm is adopted. According to the preset peak index dimension weight, sub-peak index dimension weight, and amplitude difference dimension weight, the weighted Euclidean distance value between the three-dimensional coupled feature vector and the standard three-dimensional feature vector contained in each standard sample in the angle mapping database is calculated, and the weighted Euclidean distance value is used as the similarity value.

[0135] Traverse all storage units of the angle mapping database and select the standard sample with the smallest weighted Euclidean distance value;

[0136] The theoretical azimuth angle bound to the selected standard sample is extracted as the estimated result of the target wave azimuth angle.

[0137] Among them, the weighted Euclidean distance value is the three-dimensional coupled feature vector. Compared with a standard three-dimensional feature vector in the database The weighted Euclidean distance between them is calculated using the following formula:

[0138] ;

[0139] in These are the preset weights corresponding to the peak index dimension, the sub-peak index dimension, and the amplitude difference dimension, respectively. The smaller this distance value, the higher the similarity between the 3D coupled feature vector and the standard sample in the database.

[0140] Specifically, the angle mapping database pre-stores standard three-dimensional feature vectors for all discrete azimuth angles across the entire spatial domain. During matching, the three-dimensional coupled feature vectors... With each standard sample in the database Calculate the weighted Euclidean distance separately The errors in the three dimensions are weighted by their respective values ​​before being summed by squares. Weighting, where weights are set to ensure that high-confidence dimensions dominate the cost value, while disturbances from low-confidence dimensions are suppressed by the weights. Traverse all. After the sample, Minimum means that the standard three-dimensional feature vector of the standard sample is closest to the three-dimensional coupled feature vector in the three-dimensional feature space, and the theoretical azimuth angle it is bound to is the smallest. This is the estimated result for the direction of arrival. The database is constructed independently by frequency point to ensure that the standard features used for matching correspond to the beam response characteristics at the same frequency point as the complex weighting coefficients used in actual measurements, avoiding feature mismatch caused by frequency switching. This matching process combines discrete index combination discrimination with continuous amplitude difference precise positioning, and uses continuous amplitude difference values ​​to complete fine interpolation within the angular domain interval based on coarse positioning.

[0141] In some embodiments, the method further includes:

[0142] The target's azimuth angle, slant range information, and altitude information are fused to reconstruct the target's spatial coordinates.

[0143] The reconstructed target spatial coordinates are then fed into the Kalman track filtering module for continuous and stable track tracking.

[0144] Specifically, the azimuth angle of a single frame Slope distance and altitude information Spatial coordinate fusion is performed to obtain a three-dimensional coordinate vector. After the reconstructed 3D coordinate vector is fed into the Kalman trajectory filtering module, the target motion model within the module forms prior constraints on the state prediction of the target's position and velocity. During the measurement update phase, the reconstructed 3D coordinates are used as the observation values ​​for optimal fusion. The Kalman gain is adaptively adjusted based on the relative magnitude of the measurement noise covariance and the state prediction covariance at the current moment: when the measurement noise is high, the gain decreases, and the filtered output is biased towards the predicted value; when the measurement noise is low, the gain increases, and the filtered output is biased towards the measured value.

[0145] After the above processing, the target position estimate output in each frame is a weighted fusion result of historical state prediction and current frame measurement. Random errors in single-frame azimuth measurements are smoothly filtered out by the state information of adjacent frames. The frame-by-frame position change of the filtered track in space conforms to kinematic laws, and there will be no sudden changes in target position caused by discrete jumps in single-frame angle estimates. This closed-loop processing effectively suppresses errors in the azimuth measurement stage at the back end, and the output target track appears as a stable and continuous motion trajectory on the airspace monitoring screen.

[0146] Example 2

[0147] This invention provides an angle measuring device based on a four-channel array synthesized multibeam, comprising:

[0148] The receiving and processing module is used to perform down-conversion and quadrature demodulation on the target radio frequency signal received by the four-element antenna array to obtain four native baseband complex signals and the first amplitude value of each native baseband complex signal.

[0149] The superposition module is used to perform complex domain coherent weighted superposition of the original baseband complex signals of adjacent channels based on the original baseband complex signals and the pre-calibrated complex weighting coefficients corresponding to the current operating frequency, to obtain four composite baseband signals and a second amplitude value of each composite baseband signal. The complex weighting coefficients are pre-solved based on full-space scanning data with the optimization objectives of minimizing the smoothness of the composite beam pattern and the global angle measurement error.

[0150] The equalization processing module is used to perform amplitude equalization processing on each second amplitude value based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value in the same angular domain, so as to obtain the equalized second amplitude values ​​of the four channels.

[0151] The module is used to construct a three-dimensional coupling feature vector by taking the beam channel number corresponding to the two largest values ​​in the set of all first amplitude values ​​and all equalized second amplitude values ​​and the difference between the two values.

[0152] The traversal matching module is used to perform traversal matching based on the three-dimensional coupled feature vector and the pre-constructed angle mapping database at the current operating frequency to obtain the estimated result of the target arrival azimuth angle. The angle mapping database is pre-constructed based on the eight-beam amplitude domain data of the full-space scanning of the reference array. Each standard sample in the angle mapping database contains a standard three-dimensional feature vector and its corresponding theoretical azimuth angle.

[0153] It should be noted that each module and unit in the angle measurement device based on four-channel array synthesized multibeams in this embodiment corresponds one-to-one with each step in the angle measurement method based on four-channel array synthesized multibeams in the aforementioned embodiment. Therefore, the specific implementation of this embodiment can refer to the implementation of the aforementioned angle measurement method based on four-channel array synthesized multibeams, and will not be repeated here.

[0154] Example 3

[0155] This embodiment provides an electronic device, including at least one processor and a memory. Optionally, the device further includes a communication component. The processor, memory, and communication component are connected via a bus.

[0156] In a specific implementation, at least one processor executes computer execution instructions stored in memory 302, causing at least one processor to perform the above-described method.

[0157] The specific implementation process of the processor can be found in the above method embodiments, and its implementation principle and technical effect are similar, so it will not be repeated here.

[0158] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0159] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0160] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0161] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0162] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0163] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0164] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0165] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0166] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0167] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0168] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0169] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0170] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An angle measurement method based on four-channel array synthesized multibeams, characterized in that, include: The target radio frequency signal received by the four-element antenna array is down-converted and quadrature demodulated to obtain four native baseband complex signals and the first amplitude value of each native baseband complex signal. Based on the original baseband complex signal and the pre-calibrated complex weighting coefficients corresponding to the current operating frequency, the original baseband complex signals of adjacent channels are coherently weighted and superimposed in the complex domain to obtain four composite baseband signals and the second amplitude value of each composite baseband signal. The complex weighting coefficients are pre-solved based on the full spatial scanning data with the optimization objectives of minimizing the smoothness of the composite beam pattern and the global angle measurement error. Based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value in the same angular domain, amplitude equalization processing is performed on each second amplitude value to obtain the balanced second amplitude values ​​of the four channels. Construct a three-dimensional coupling feature vector by taking the beam channel numbers corresponding to the two largest values ​​in the set of all first amplitude values ​​and all equalized second amplitude values, and the difference between the two values. The estimated azimuth angle of the target wave is obtained by traversing and matching the three-dimensional coupled feature vector and the pre-constructed angle mapping database at the current operating frequency. The angle mapping database is pre-constructed based on the eight-beam amplitude domain data of the full-space sweep of the reference array. Each standard sample in the angle mapping database contains a standard three-dimensional feature vector and its corresponding theoretical azimuth angle.

2. The method according to claim 1, characterized in that, The step of performing amplitude equalization processing on each second amplitude value based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value within the same angular domain to obtain four-channel equalized second amplitude values ​​includes: The first amplitude value and the second amplitude value are dB domain amplitude observation values ​​obtained after performing dB domain conversion on the modulus of the baseband complex signal; For any composite baseband signal generated by the coherent superposition of the native baseband complex signals of two adjacent channels, the angular domain range defined by the two adjacent channels constituting the composite baseband signal is determined as the current angular domain range of the composite baseband signal. Select the first amplitude value that is within the current angular domain range and has the largest amplitude value from the four first amplitude values ​​as the reference amplitude value; The dB-domain difference calculation is performed between the reference amplitude value and the maximum value among the four second amplitude values ​​to obtain the amplitude difference margin. Based on the comparison result between the amplitude difference margin and the preset amplitude constraint threshold, the adaptive equalization attenuation factor is updated in a closed-loop iterative manner. In the dB domain, the updated adaptive equalization attenuation factor is subtracted from the four second amplitude values ​​to obtain the four equalized second amplitude values.

3. The method according to claim 2, characterized in that, The step of updating the adaptive equalization attenuation factor according to the comparison result between the amplitude difference margin and the preset amplitude constraint threshold in a closed-loop iterative manner includes: The initial value of the adaptive equalization attenuation factor is set to a preset fixed value; When the amplitude difference margin is less than the preset amplitude constraint threshold, it is determined that the composite beam gain is too high, and the adaptive equalization attenuation factor is increased by a preset step size. When the amplitude difference margin is greater than the sum of the preset amplitude constraint threshold and the preset amplitude redundancy threshold, it is determined that the equalization attenuation is excessive, and the adaptive equalization attenuation factor is reduced by a preset step size. When the amplitude difference margin is greater than or equal to the preset amplitude constraint threshold and less than or equal to the sum of the preset amplitude constraint threshold and the preset amplitude redundancy threshold, the adaptive equalization attenuation factor remains unchanged.

4. The method according to claim 2, characterized in that, The method further includes: Set the upper and lower limits of the adaptive equalization attenuation factor; After each update of the adaptive equalization attenuation factor, it is determined whether the updated adaptive equalization attenuation factor exceeds the upper limit value or the lower limit value. If the updated adaptive equalization attenuation factor is greater than the upper limit value, then the adaptive equalization attenuation factor is limited to the upper limit value; If the updated adaptive equalization attenuation factor is less than the lower limit value, then the adaptive equalization attenuation factor is limited to the lower limit value.

5. The method according to claim 1, characterized in that, The angle mapping database includes a first sample set independently constructed for the 1030MHz frequency point and a second sample set independently constructed for the 1090MHz frequency point; according to the current working frequency point, standard samples of the corresponding frequency point are selected from the first sample set or the second sample set to participate in the traversal matching.

6. The method according to claim 1, characterized in that, The step of traversing and matching based on the three-dimensional coupled feature vector and the pre-constructed angle mapping database at the current operating frequency to obtain the target's azimuth angle includes: A weighted Euclidean distance similarity matching algorithm is adopted. According to the preset peak index dimension weight, sub-peak index dimension weight, and amplitude difference dimension weight, the weighted Euclidean distance value between the three-dimensional coupled feature vector and the standard three-dimensional feature vector contained in each standard sample in the angle mapping database is calculated, and the weighted Euclidean distance value is used as the similarity value. Traverse all storage units of the angle mapping database and select the standard sample with the smallest weighted Euclidean distance value; The theoretical azimuth angle bound to the selected standard sample is extracted as the estimated result of the target wave azimuth angle.

7. The method according to claim 1, characterized in that, The method further includes: The target's azimuth angle, slant range information, and altitude information are fused to reconstruct the target's spatial coordinates. The reconstructed target spatial coordinates are then fed into the Kalman track filtering module for continuous and stable track tracking.

8. An angle measuring device based on a four-channel array synthesized multibeam, characterized in that, include: The receiving and processing module is used to perform down-conversion and quadrature demodulation on the target radio frequency signal received by the four-element antenna array to obtain four native baseband complex signals and the first amplitude value of each native baseband complex signal. The superposition module is used to perform complex domain coherent weighted superposition of the original baseband complex signals of adjacent channels based on the original baseband complex signals and the pre-calibrated complex weighting coefficients corresponding to the current operating frequency, to obtain four composite baseband signals and a second amplitude value of each composite baseband signal. The complex weighting coefficients are pre-solved based on full-space scanning data with the optimization objectives of minimizing the smoothness of the composite beam pattern and the global angle measurement error. The equalization processing module is used to perform amplitude equalization processing on each second amplitude value based on the amplitude difference margin between all second amplitude values ​​and the preferred first amplitude value in the same angular domain, so as to obtain the equalized second amplitude values ​​of the four channels. The module is used to construct a three-dimensional coupling feature vector by taking the beam channel number corresponding to the two largest values ​​in the set of all first amplitude values ​​and all equalized second amplitude values ​​and the difference between the two values. The traversal matching module is used to perform traversal matching based on the three-dimensional coupled feature vector and the pre-constructed angle mapping database at the current operating frequency to obtain the estimated result of the target arrival azimuth angle. The angle mapping database is pre-constructed based on the eight-beam amplitude domain data of the full-space scanning of the reference array. Each standard sample in the angle mapping database contains a standard three-dimensional feature vector and its corresponding theoretical azimuth angle.

9. An electronic device, characterized in that, include: At least one processor, at least one memory, and computer program instructions stored in the memory, which, when executed by the processor, implement the method as described in any one of claims 1-7.

10. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, The method as described in any one of claims 1-7 is implemented when the computer program instructions are executed by the processor.

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