943 results about "Array element" patented technology

The invention relates to the technical field of defect detection, and discloses a flange forging defect detection method and system. The method comprises the following steps: performing three-dimensional scanning and material acoustic characteristic measurement on a to-be-detected wind power flange to obtain layer partition sound isolation path data; generating an array element excitation control file of the double-array phased array ultrasonic detection system; applying the array element excitation control file to a double-array phased array ultrasonic detection system, and performing micro defect feature enhancement on a received echo signal to obtain a feature-enhanced signal data set; performing ultrasonic emission and data acquisition on the wind power flange to obtain a global detection data set; and inputting the global detection data set into the two-stage defect detection model for defect feature extraction and classification evaluation, and generating a defect detection evaluation report. According to the method, the detection rate and the classification accuracy of the micro forging defects are improved.

The invention discloses a composite board ultrasonic defect detection method which comprises the following steps: S1, fixing a carbon fiber circumferential winding composite pressure container on a bracket, and establishing a coordinate system with the axis of the container as a z axis; s2, a 40 MHz dry coupling phased array ultrasonic probe is attached to the scanning starting point, and the contact angle of the probe is recorded; s3, moving the probe along the spiral track of the outer surface of the container at the speed of 20mm / s, and collecting A-scanning echo signals of all array elements; s4, performing pulse compression and time domain deconvolution processing on the acquired signal to obtain a time domain echo sequence; s5, delay time is calculated according to the shell curvature, the array element signals are compensated, and focusing B-scanning data are generated; s6, splicing the B-scanning data at the step length of 0.5 mm * 0.5 mm, and reconstructing C-scanning data corresponding to the space coordinates; and S7, inputting the C-scanning data into the trained Transform network, and outputting defect types, sizes and three-dimensional coordinates. The method realizes high-frequency ultrasonic composite board defect accurate detection, remarkably improves the microcrack recognition rate, and is widely applied to safety evaluation scenes of high-pressure hydrogen storage tanks and pressure vessels.

The invention relates to the technical field of TDOA (time difference of arrival) positioning, and provides an ultrasonic three-dimensional positioning method based on beam enhancement and TDOA, which comprises the following steps: extracting initial space parameters based on beam scanning of an array receiving signal, carrying out iterative optimization on beam weight to adjust a direct wave component and suppress reflection interference, constructing a closed-loop optimization mechanism, and carrying out beam enhancement and TDOA positioning. Calculating an enhanced signal and an array element reliability measurement index through frequency domain segmentation and energy normalization; forming an optimization array based on the array element reliability measurement index, extracting a time delay parameter from the optimization array, constructing a distance measurement equation set, and calculating an initial estimation value of a target position by adopting a weighted optimization algorithm; and constructing a residual error model, constructing an optimized weight matrix by combining an array element reliability measurement index and a signal quality index, iteratively calculating a target coordinate until a convergence condition is met, and outputting a final three-dimensional coordinate. According to the method, the comprehensive performance of ultrasonic three-dimensional positioning in the aspects of anti-interference performance, stability and positioning precision in a complex environment is improved, and error source control is realized.

The invention discloses a rubber-lined pipeline defect detection method and system, and the method comprises the steps: arranging an ultrasonic probe array, obtaining large-area scanning information of a rubber-lined pipeline, collecting an ultrasonic signal, an echo signal and a resonance signal, generating a resonance signal curve, and reflecting a mapping image of the interior of the rubber-lined pipeline. And calculating a half-power bandwidth and a damping characteristic parameter, generating a corresponding characteristic vector through the identification model, identifying and positioning defects in the rubber-lined pipeline, evaluating the severity of the defects, and outputting an identification result. Through the structural design of arranging a plurality of array elements of the array probe, the coverage range is increased, ultrasonic wave emission and receiving are carried out on the rubber-lined pipeline from different angles and positions, the probability of discovering small-area debonding is improved, in addition, the machine learning technology is combined, an intelligent recognition model is trained, rich features are provided, and the detection accuracy is improved. The capability of identifying different types of defects is enhanced, the sensitivity to different types of defects is improved, and the risk of missing detection of small-area debonding is reduced.

The invention provides a high-imaging-resolution method for identifying a lead sealing defect part of a cable, and relates to the field of nondestructive testing. Comprising the steps that a linear array probe array is utilized, a plurality of array elements emit ultrasonic waves to a to-be-detected defect part at the same time, and a received echo signal reflects the waveform shape and the waveform phase of the defect. A two-dimensional image is preprocessed through a synthetic aperture focusing technology, a combined image is reprocessed through a phase coherence technology, the quality and accuracy of the image are further improved, and a high-resolution three-dimensional image is constructed in combination with an imaging synthetic aperture focusing technology. The ultrasonic phased array technology, the SAFT technology, the phase coherence technology and the synthetic aperture focusing technology are combined, the imaging resolution is effectively improved, the method has remarkable advantages especially when defect parts in complex structures such as cable lead seals are recognized, the imaging quality is optimized, a two-dimensional image is converted into a high-resolution three-dimensional image, and finally an accurate defect recognition result is obtained.

The invention discloses a projection dimensionality reduction rapid calculation method and system for a large-scale spherical column phased array scanning beam dynamic activation subarray plane, and belongs to the field of phased array measurement and control performance modeling, and the method comprises the steps: S1, setting parameters of a scheduling problem model; s2, acquiring orbit data of the aircraft, obtaining a visible time window set and calculating a visible arc section; s3, establishing a phased array resource set, and searching for an activated array element; and S4, establishing a large-scale phased-array antenna multi-beam scheduling objective function, and obtaining a final calculation result. According to the invention, the multi-beam measurement and control performance can be improved.

The invention provides an acoustic array adaptive calibration correction system applied to an underwater moving target, which relates to the technical field of marine equipment and comprises a multi-source excitation and environment perception module, an intelligent array perception and diagnosis module, an adaptive position inversion and uncertainty quantification module and a closed-loop calibration execution and self-learning optimization module. The multi-source excitation and environment perception module is responsible for providing reference signals required by calibration and establishing a correlation model of environment and formation distortion, and the intelligent array perception and diagnosis module realizes multi-modal data acquisition, array element health state monitoring and formation geometry self-perception. The adaptive position inversion and uncertainty quantization module completes signal processing, position estimation and error quantization propagation, and the closed-loop calibration execution and self-learning optimization module executes a compensation strategy, verifies a calibration effect and continuously optimizes system performance through online learning; the system solves the problem that a traditional method cannot process environment time varying, multi-sensor conflicts and uncertainty quantization.

The invention relates to a nonlinear ultrasonic guided wave phased array imaging method based on mixed array elements and time reversal. The method comprises the following steps: exciting a fundamental wave and receiving a second harmonic wave at piezoelectric array elements of the fundamental wave and the second harmonic wave of an ultrasonic guided wave by using a center frequency respectively; full-matrix data of ultrasonic guided wave signals in the detected workpiece are obtained in a one-transmitting and one-receiving mode; a fundamental wave signal is suppressed and a second harmonic signal is enhanced by adopting a pulse inversion mode; for the full-matrix data after pulse inversion, utilizing continuous wavelet transform filtering to extract a second harmonic signal; respectively calculating the distance from the discretized imaging area to the excitation array element and the distance from the discretized imaging area to the receiving array element; and for each discrete pixel point, according to an excitation signal of a distance forward propagation fundamental wave and a received second harmonic signal back propagation, a pixel value is calculated by using a time domain topology energy equation, and local acoustic nonlinear imaging of the plate-shaped structure is realized.

The invention discloses a sparse cloth double-array element multi-frequency ambiguity resolution interference angle measurement method and system, relates to the technical field of radar measurement, realizes design of a multi-frequency signal frequency selection criterion, and further realizes non-ambiguity and high-precision angle measurement of all angles in an angle range required by engineering. According to the technical scheme, a physical baseline length and a reference frequency are set according to a layout space; deriving a plurality of signal carrier frequency design criteria according to the Chinese remainder theorem; calculating the carrier phase difference of the double-array-element receiving signals under different signal carrier frequencies; and reconstructing the congruence equation set, and solving the congruence equation set to solve ambiguity so as to obtain a target angle estimation value.

The invention relates to the technical field of signal analysis, in particular to a GNSS (Global Navigation Satellite System) detection method and system based on machine learning, and the method comprises the steps: receiving a navigation radio-frequency signal containing reality and deception, and carrying out the down-conversion of an RF (Radio Frequency) front end to obtain intermediate-frequency data; gNSS signal capture is completed by searching correlation peaks in frequency and code phases based on intermediate frequency data; in the capturing stage, a motion state, a correlation peak number, a noise value, capturing parameters and peak + / -1 chip sampling features are extracted and input into a machine learning classification model to judge whether cheating exists or not; if so, separating the deception signal from the real signal, and respectively sending the deception signal and the real signal into independent tracking channels; measuring an array element carrier relative phase by an array antenna, establishing a phase center model, and correcting to obtain an effective phase center and a differential baseline; according to the method, a deception azimuth angle and a pitch angle are obtained, a beam weight is calculated, a deception direction is subjected to null setting, a real direction is subjected to main lobe protection, and a weight value is fed back in real time to improve a signal carrier-to-noise ratio and locking stability. According to the invention, the problem that the existing commercial GNSS signal is low in power and easy to be interfered by deception is solved.

The invention discloses a large-scale phased array multi-channel partition beam control method and device based on an FPGA and a storage medium. The method comprises the steps that a control instruction of an antenna control unit is acquired; analyzing the control instruction which is verified to be correct, judging an instruction type according to an analysis result, when the instruction type is a beam switching instruction, determining a beam control parameter in the instruction, and calculating a base code of the phased-array antenna according to the beam control parameter; the array elements of the phased-array antenna are divided into a plurality of areas, according to the base codes and the position coordinates of the array elements, the wave control codes of the array elements are calculated in parallel by adopting a multi-channel partitioning method, and the wave control codes are normalized and then written into a beam forming chip in parallel; and after the operation is completed, a corresponding response instruction is sent to the antenna control unit. The method has the advantages of being high in beam switching speed, small in resource consumption and good in universality, an array can form a sparse array in the mode of sending a control instruction, and therefore side lobes are restrained, and power consumption is reduced.

The invention relates to an ultrasonic phased array full-focusing imaging method for acoustic wave multi-path propagation compensation of a layered composite material, which is characterized by comprising the following steps of: arranging an ultrasonic phased array probe with N array elements on a composite material piece to be detected, obtaining complete echo data by taking each array element as a transmitting array element and taking all array elements as receiving array elements in sequence in a full-matrix acquisition mode; a two-dimensional pixel grid is established in an imaging area, a Monte-Carlo perturbation mechanism used for representing the acoustic wave propagation uncertainty in the layered composite material is introduced into a propagation model for each emission array element-receiving array element-pixel point combination, and the acoustic beam emission direction, the propagation path and the equivalent acoustic velocity are subjected to random perturbation, so that the acoustic wave propagation uncertainty in the layered composite material can be represented. Generating a plurality of equivalent sound wave propagation paths, calculating two-way propagation time of each path, and performing weighted statistics on energy contributions of different paths according to array element sound beam directivity to obtain equivalent propagation time delays of pixel points; and performing delay correction on a full-matrix echo signal by using the equivalent propagation time delay, and performing coherent superposition on signals of all transmitting-receiving array element combinations to realize dynamic focusing of a full-pixel grid, and finally reconstructing an ultrasonic full-focusing imaging image with high resolution and high signal-to-noise ratio. The time delay error caused by propagation path deviation and sound velocity non-uniformity in the layered composite material can be effectively compensated, the focusing precision and spatial resolution of full-focusing imaging are improved, meanwhile, an existing TFM imaging frame does not need to be changed, and the method has good engineering implementability and popularization and application value.

The invention discloses a broadband digital beam forming method based on a Farrow filter, and the method comprises the following steps: carrying out the DDC down-conversion and phase shift processing of a signal after the analog-to-digital conversion of a broadband signal is completed through an ADC; calculating the delay inequality of each array element signal relative to a reference array element, and decomposing the delay inequality into an integer sampling period and a fractional delay component; a fourth-order Lagrange type Farrow filter oriented to FPGA / DSP optimization is adopted to carry out fractional time delay compensation, and coefficients of the Farrow filter are dynamically adjusted through a polynomial expansion formula; and finally, performing complex weighted synthesis on each channel filtering signal to generate a directional wave beam. According to the method, high-precision fractional delay adjustment is achieved, the Farrow filter is adopted, the tedious process of recalculating coefficients can be omitted, only the P value is changed, and high-precision beam direction control can be achieved under the condition of low calculation amount.

The invention discloses a passive synthetic aperture method and device based on R-L deconvolution beam domain processing, a medium and equipment, and the method comprises the steps: constructing a formation distortion model of a towed array under disturbance, and processing a discretized formation distortion model through a Kalman filter, so as to obtain the absolute coordinates of each array element; determining a receiving signal time domain solution of each array element based on the sound pressure expression and the absolute coordinates; based on an ETAM algorithm, obtaining beam output of overlapped sub-arrays in adjacent time samples, and performing R-L iteration on the beam output to obtain a phase compensation factor; and performing phase compensation based on the wave beam output of the phase compensation factor to obtain each phase correction wave beam and the wave beam output of the synthetic aperture. The passive synthetic aperture algorithm and the R-L deconvolution wave beam forming technology are effectively combined, so that the accuracy of the phase compensation factor after formation distortion is generated is improved to the maximum extent, and the accuracy of the phase correction wave beam is improved. Therefore, the algorithm provided by the invention still provides high-precision target positioning under the condition that the ETAM algorithm fails.

The invention discloses an imaging method, system and device for correcting range migration based on frequency domain phase multiplication, and the method comprises the following steps: carrying out the range pulse compression of echo data of each receiving array element in a range frequency domain; performing data preprocessing according to a phase center approximation method to obtain equivalent transmit-receive combined synthetic aperture sonar data; deriving a secondary distance compression item at the reference distance in the two-dimensional frequency domain, and performing secondary distance compression processing; deriving a space-variant migration phase term of range migration correction corresponding to each target with different distances; carrying out filtering processing on the two-dimensional frequency domain sonar data; a filtered result is converted to a range-direction time domain and an azimuth-direction Doppler domain, data of targets at corresponding distances are extracted, and the data extracted each time are combined in sequence; and for the data after range migration correction, azimuth pulse compression is carried out in a range time domain and an azimuth Doppler domain, and the data is converted to a two-dimensional time domain to obtain a sonar image.

The invention discloses a multi-strategy joint improved sparse area array optimization method and system, and the method comprises the steps: calculating the peak side lobe level of each initial array element distribution, and obtaining the current lowest peak side lobe level and the optimal array element distribution corresponding to the lowest peak side lobe level, updating the positions of the array elements according to an ascending stage, a descending stage and a landing stage in the improved dandelion optimization algorithm; starting a Cauchy spiral inverse cumulative distribution variation strategy to vary the positions of the array elements, calculating the target lowest peak side lobe level of the updated array element distribution, and if the value of the target lowest peak side lobe level is greater than the value of the lowest peak side lobe level, replacing the updated array element distribution; and updating the global optimal array element distribution position and the corresponding lowest peak sidelobe level. The efficiency of the algorithm in the aspects of global search and local development is improved, the algorithm is prevented from being caught in local optimum too early, and therefore the solving precision and the convergence speed of the algorithm are improved.

The embodiment of the invention provides a transducer echo line sequence test method and a transducer echo line sequence test device, and the method comprises the steps: enabling a detection surface and a horizontal plane to form a first angle in an echo detection state, comparing waveform data of feedback signals obtained by reflecting the ultrasonic signals emitted by the plurality of test array elements through the detection surface with preset qualified data to determine a performance result of the transducer; in the line sequence detection state, a second angle is formed between the detection surface and the horizontal plane, and the actual flight time difference value of each adjacent test array element in the plurality of test array elements is determined according to waveform data of feedback signals obtained by reflecting ultrasonic signals emitted by the plurality of test array elements through the detection surface, and according to a comparison relation between a difference value between the actual flight time difference value and the theoretical flight time difference value and a preset threshold value, whether welding of each test array element is correct or not is determined. Therefore, an echo performance detection function and a multi-array element line sequence detection function can be integrated.

The invention relates to a sparse cloth double-array-element phase comparison and double-frequency phase solution ambiguity radar angle measurement method and device, and belongs to the technical field of radar measurement. The method specifically comprises the following steps of: 1, performing phase comparison measurement on sparse cloth double array elements at a dual-carrier frequency and a lower dual-channel to obtain a phase difference between the array elements so as to obtain a fuzzy coefficient containing a phase error; according to the fuzzy coefficient, determining constraint conditions of dual-frequency and carrier wave values; step 2, under the constraint condition determined in the step 1, selecting a radar signal working frequency, and constructing a virtual short baseline according to the dual-array-element phase difference under different frequencies; and step 3, based on a virtual baseline ambiguity resolution method, calculating to obtain a non-ambiguity high-precision one-dimensional angle measurement angle.

The invention provides a method and a system for array shape estimation and target detection during steering of towed line array sonar. The method comprises the following steps: S1, modeling a distorted towed line array into a parabola model; s2, parabola parameter values and other parameter values are set; s3, calculating the position coordinates of each array element and the corresponding position slope; s4, calculating to obtain a gradient vector of the target function; s5, judging whether the absolute value of the gradient vector of the target function is smaller than an estimation error threshold or not, and if yes, outputting a current parabola parameter value; if not, the parameter value of the parabola is updated again, and the steps S2-S4 are repeated. According to the method, the formation estimation problem is converted into a least square optimization problem, an iterative solving algorithm of the problem is given through a forward and backward propagation calculation method, only the shipborne or towed active sonar on the ship is used for transmitting pulse signals, an existing towed line array does not need to be transformed, the algorithm principle is simple, the calculation amount is small, and the method is suitable for large-scale popularization and application. And engineering realization is easy.

The invention relates to the technical field of underwater acoustic signal processing in a sonar system, in particular to a large-aperture array robust adaptive waveform recovery method based on focusing covariance sparse reconstruction, and the method comprises the steps: carrying out the time-frequency transformation of all array element receiving time domain data, and obtaining array element domain-frequency domain data; constructing sampling covariance matrixes corresponding to different frequency points according to the array element domain-frequency domain data; constructing a multi-frequency-point focusing covariance matrix according to the sampling covariance matrix and the array manifold vector corresponding to each frequency point; constructing a sparse dictionary matrix adaptive to the focusing covariance matrix according to the linear relation between the focusing covariances of the frequency points, and obtaining a sparse expression of the focusing covariance matrix; according to the sparse representation form of the focusing covariance matrix, utilizing a sparse criterion to carry out iterative reconstruction on the focusing covariance matrix; and robust adaptive waveform recovery is carried out by using the focusing covariance matrix after sparse iteration reconstruction. According to the method, the short-time adaptive waveform recovery performance of the large-aperture array is remarkably improved.

The invention discloses an underwater sound environment sensing method based on multi-array-element sparse channel estimation. An underwater sound receiving end receives signals transmitted through an underwater sound multipath channel through a multi-array-element array; performing Hilbert transform on the receiving signal of each array element to obtain an analysis signal, and calculating a cross-correlation function of the analysis signal and the transmitting signal; based on the cross-correlation function, sparse channel parameters, including path amplitude and time delay, of each array element are estimated by adopting an orthogonal matching pursuit algorithm combined with a constant false alarm detection dynamic threshold value; the method comprises the following steps: constructing an array response vector by using sparse channel parameters of a multi-array element array, and searching and estimating angles of arrival, including a direction angle and a pitch angle, of a multipath signal through a spatial spectrum peak value; and based on the arrival angles, amplitudes and time delays of the direct path and the reflection path, inverting an underwater environment structure through a ray acoustic theory, including a reflection point distance and a reflection surface normal vector, so as to realize three-dimensional perception of the underwater reflector. According to the invention, multipath resolution can be improved, and false alarm and missing detection can be effectively reduced.

A sonar platform self-noise interference removal method and system, a device, and a storage medium. The method comprises: mounting a hydrophone array on one side of a sonar platform; dividing a sonar platform space into a grid, and constructing matrix A1 using an acoustic transfer function between each point on the grid and each array element; dividing a target radiation sound source space into a grid, and constructing matrix A2 using an acoustic transfer function between each point on the grid and each array element; concatenating matrix A1 and matrix A2 to form matrix A; using an acoustic transfer function of a unit point sound source at the position of an i-th array element at each point in the sonar platform space to construct matrix B1i, and constructing an all-zero matrix B2; concatenating matrix B1i and the all-zero matrix B2 to form matrix Bi; solving using matrix A and matrix Bi to obtain a weighting coefficient qi: assuming that a signal acquired by the hydrophone array is matrix X, and thus a self-noise component on the i-th array element is expressed as ni＝qiX, subtracting ni from a signal received by the i-th array element to obtain a signal not containing the self-noise component; and implementing removal of self-noise on each array element.

The invention relates to the technical field of full-focusing phased arrays, and discloses an on-line automatic bar flaw detection method and device based on a full-focusing phased array technology. According to the method, after water immersion type coupling is carried out, array elements of a concave array phased array probe are excited in a plane wave emission mode, multi-angle acoustic beams are formed, and full-matrix echo data are captured; for transverse wave detection, the sound field uniformity is improved by adopting a grouped alternate emission mechanism. Full-domain dynamic focusing is realized through coherent superposition processing, and real-time alarm and mark spraying are carried out on standard exceeding defects in combination with encoder data. The device comprises an off-line automatic calibrator, a conveying roller way, a steel splitting instrument platform, a pinch roll system, a lifting transverse moving platform, an ultrasonic detection host, a mark spraying system, a water circulation system and a PLC system, and efficient and accurate on-line bar flaw detection is achieved.

The invention provides a DOA estimation and error correction method and device based on joint sparse recovery, and the method comprises the steps: receiving a target signal through a linear array, building an array signal model fusing a phase error, and constructing an optimization model based on multiple measurement vectors; and compensating the phase error in each step of iteration by using an iterative optimization solution algorithm to enable the DOA to gradually approach a true value, thereby obtaining estimation results of the spatial spectrum and the phase error. The method provided by the invention has the advantages that random phase errors caused by array element position errors, system frequency errors, sound wave propagation errors and the like in DOA estimation are corrected. Under the condition that phase errors exist, a signal model and an optimization problem are constructed, and the phase errors and a DOA estimation value are solved through an iterative algorithm, so that a high-precision and low-sidelobe DOA estimation result is obtained. The method is suitable for DOA estimation under the conditions of small snapshots, strong noise and random phase errors.

The invention provides a phased array composite material ultrasonic flaw detector control method and system, and relates to the technical field of ultrasonic detection, and the technical scheme is characterized in that multi-point distance data between a phased array probe and a detected curved surface of a composite material component is acquired; calculating local geometric parameters of a measured curved surface below the phased array probe based on the multi-point distance data; the actual transit time of ultrasonic echoes from a characteristic reflector in the composite material component is obtained; according to the calculated local geometric parameters and the obtained actual transit time of the ultrasonic echoes, the equivalent propagation sound velocity for representing propagation of the ultrasonic waves in the composite material component is determined; and calculating excitation delay time for each array element of the phased array probe according to the calculated local geometric parameters and the determined equivalent propagation sound velocity. The phased array composite material ultrasonic flaw detector control method and the phased array composite material ultrasonic flaw detector control system provided by the invention have the advantages of improving the detection sensitivity and the accuracy of defect evaluation.

The invention discloses a GNSS anti-interference closed-loop phase self-correction method based on deep learning, and relates to the technical field of satellite navigation and artificial intelligence, and the method comprises the steps: obtaining an anti-interference array output signal and weight information through an array antenna and space-time adaptive processing; extracting a carrier-to-noise ratio, a weight phase feature and historical positioning quality, and constructing a deep learning feature vector; reasoning an array element-level phase correction reference quantity by using a multi-layer perceptron model, and realizing accurate phase compensation of an array output signal by combining phase error layered modeling, quick-change disturbance prediction and weight sensitivity estimation; an anti-interference perception observation covariance dynamic scaling mechanism is introduced into RTK positioning calculation; on-line learning and model updating are triggered through a positioning quality evaluation result, so that the system has an adaptive evolution capability. According to the method, the GNSS carrier phase quality and the positioning precision under the strong interference condition can be remarkably improved, deep fusion of anti-interference processing and high-precision positioning is realized, and the method has important engineering application value.

The invention relates to the field of underwater sound signal processing, in particular to an underwater DOA (direction of arrival) estimation method based on graph nerves and a convolutional neural network, which comprises the following steps: 1, establishing a linear array, and enabling narrow-band signals to simultaneously reach an underwater sound array; 2, performing signal preprocessing to obtain a signal covariance matrix, and performing normalization processing; 3, extracting correlation between array elements and spatial features of array signals, and performing data supplementation on sparse linear array information; 4, forming a double-branch structure, enhancing the information aggregation capability, and extracting features from a space path and a time domain path; and 5, constructing an adjacent matrix, filling node features of damaged array elements, adopting a double-branch structure, extracting spatial features and time domain features, carrying out feature integration, and outputting a DOA estimation result. The spatial correlation between array elements is extracted and the array sparsity problem is processed by using the graph neural network, and the time domain features of the signals are extracted in combination with the convolutional neural network, so that more accurate and more robust DOA estimation can be realized under the conditions of low signal-to-noise ratio and array sparsity.

The invention relates to the technical field of array signal processing, in particular to a space-frequency power inversion anti-interference method fusing SMI-LDL decomposition. The problems that an existing space-time anti-interference technology is high in calculation complexity, and real-time processing is difficult to achieve in limited resources of a navigation receiver are mainly solved. The method comprises the following steps: firstly, converting a radio frequency signal received by an array into a digital intermediate frequency signal and carrying out sliding window partitioning processing; windowing the data block and performing FFT (Fast Fourier Transform) to obtain a frequency domain array; then calculating an auto-covariance matrix R of other array elements except the reference array element and a cross-covariance matrix r of the reference array element and other array elements; lDL decomposition is carried out on the auto-covariance matrix to obtain a lower triangular matrix L and a diagonal matrix D, and inversion is carried out on the lower triangular matrix L and the diagonal matrix D respectively, so that huge operand caused by direct inversion of the covariance matrix is avoided; and finally, calculating an optimal weighting vector according to a power inversion criterion, and performing spatial filtering on the frequency domain data.

A method for processing multi-dimensional data, comprising the steps providing a non-procedural declarative definition of a data array, the definition being syntactically in the form of a query wherein respective values of individual array elements are defined using query conditions constraining the values; generating a naïve query representing a straight-forward generation and computation of the query; optimizing the naïve query using a query optimizer, yielding a procedural execution plan arranged to, when run, determine the respective values of the array elements; and calculating the respective values of the array elements by executing or running computer code of the execution plan.

The invention relates to a phased array tracking method based on four-dimensional joint weighted dynamic pre-switching, and belongs to the technical field of phased array communication. The method comprises the following steps: updating space-time correlation parameters to a target historical motion track database, and generating a target state prediction value based on a UKF prediction method; starting a four-dimensional joint gradient weighting program, carrying out linear phase interpolation of a time delay dimension, and generating a control signal with a continuous phase; solving a mutual coupling matrix, establishing a cross-array-plane phase mapping model based on cubic spline interpolation, and compensating a residual phase error; according to the real-time radar cross section, the number of effective array elements participating in beam forming is dynamically adjusted, a final beam pointing signal is generated, and stable relay tracking of the current period is completed. The method solves the problems of phase jump and signal attenuation during multi-array-plane switching, and is suitable for continuous tracking in a high-speed moving scene of the unmanned aerial vehicle.