65 results about "Electromagnetic vector sensor" patented technology

The invention provides a method for estimating parameters of a space stretching electromagnetic vector sensor array. The method comprises the steps of receiving K unrelated incoming signals through a receiving array, and constructing guide vectors of the incoming signals corresponding to the array; expressing the guide vectors of the incoming signals as a product of a spatial domain function array and a polarizational domain function vector; computing a covariance matrix of the received data; analyzing features of the covariance matrix of the received data to obtain signal subspace and noise subspace; constructing a multi-signal classified MUSIC spatial-polarizational domain combination zero spectrum function, and maximizing the spatial-polarizational domain combination zero spectrum function; performing MUSIC dimension reduction process to separate a spatial domain spectrum and a polarizational domain spectrum by means of the self-conjugate moment Rayleigh-Ritz entropy theorem, performing traversal search within value ranges of variables and estimating signal parameters. By means of the method, four-dimensional MUSIC search is transformed into two-dimensional spatial domain search and two-dimensional polarizational domain search, and therefore, calculated quantity is decreased.

The invention discloses a bidimensional wave arrival direction estimation method based on a non-concentric electromagnetic vector array radar. The bidimensional wave arrival direction estimation method mainly solves the problems of serious cross coupling and low estimated accuracy of a polarization array radar in the process of target positioning and tracking. The method includes a first step of building receiving data of a sparse uniform non-concentric electromagnetic vector sensor array, a second step of carrying out eigenvalue decomposition to the received data to obtain a signal subspace, a third step of obtaining dim direction cosine precision estimation according to signal subspace tectonic rotation invariant relationship equation, and through utilization of the least square algorithm, a fourth step of obtaining non-dim-direction cosine rough estimation through utilization of the signal subspace, and a fifth step of combining the dim direction cosine precision estimation and the non-dim-direction cosine rough estimation, the bidimensional wave arrival direction estimation can be obtained. The bidimensional wave arrival direction estimation method effectively expands array physical apertures on the condition of not adding array elements and complexity of hardware, enables the bidimensional wave arrival direction estimation accuracy to be greatly improved, and can be applied to accurate positioning and tracking of the radar to targets.

The invention discloses an electromagnetic vector sensor array amplitude and phase error self-correcting method based on array rotation. The method includes: an electromagnetic vector sensor with amplitude and phase errors is used as a receiving array and installed on a rotation device to receive a transverse electromagnetic wave calibration source signal, two groups of sampling data of an array output signal are received before the array rotates and after the array rotates 90 degrees around a z axis in clockwise mode, a sampling signal autocorrelation matrix formed by the two groups of sampling data is calculated, characteristic decomposition is performed on the sampling signal autocorrelation matrix to obtain signal guiding vector estimation values before and after rotation of an array and estimate an amplitude and phase error matrix, and an array element to be corrected receives an inverse matrix of a data premultiplication amplitude and phase error matrix so as to achieve correction of amplitude and phase errors. The electromagnetic vector sensor array amplitude and phase error self-correcting method based on the array rotation can estimate amplitude errors and signal arrival angles of the signal of the electromagnetic vector sensor, has high parameter estimation accuracy, does not need iterative operation, and is small in calculated amount.

The invention discloses a method for self-correcting a coupling error of an electromagnetic vector sensor array. According to the method, an ideal electromagnetic vector sensor is additionally arranged to be used as an auxiliary array element and forms a receiving array with the electromagnetic vector sensor array to be corrected, the receiving array receives the completely polarized transverse electromagnetic wave signal data of a far field, the autocorrelation matrix of the sample data is calculated, the real electromagnetic field vector and electromagnetic vector having errors of the signal are estimated through a subspace method, the obtained estimated value of the real electromagnetic field vector and the estimated value of the electromagnetic field vector having errors are used to estimate the coupling error variance, the coupling error matrix is constructed according to the coupling error variance and the inverse matrix is calculated, and the data received by the electromagnetic vector sensor to be corrected are pre-multiplied by the inverse matrix of the coupling error matrix so as to correct the coupling error. The method disclosed by the invention has a simple solving process and small calculated amount, the real electromagnetic filed vector and the electromagnetic field vector having coupling errors of the signal can be estimated, and higher coupling error estimation accuracy can be achieved.

The invention relates to a tensor modeling based DOA and polarized parameter estimation method of a polarized array, belongs to the techcnial field of radar array signal processing, and aims at solving the problem that a present DOA and polarized estimation method of the polarized array via an electromagnetic vector sensor needs to search/solve DOA and polarized parameters in a combined way and ishigh in calculating complexity. The method comprises that 1) a 4D tensor covariance is constructed according to received data; 2) two dimensions of the obtained 4D tensor covariance are transposed and then projected into a 2D matrix according to the sequence in the spatial and polarization domains; 3) singular value decomposition or characteristic value decomposition is carried out on the 2D matrix in the step 2), and a DOA estimated value is solved further; and 4) the DOA estimated value obtained in the step 3) is used to estimate an array guiding matrix, and the polarized parameter vector is estimated. The method can be used to solve the DOA and polarization parameter of the polarized array structure in any linear arrangement independently, and the computing complexity is reduced.

The invention relates to a method for multi-parameter joint estimation of a distributed type electromagnetic vector sensor array and belongs to the field of array signal processing. Received data of the distributed type electromagnetic vector sensor array are constructed, covariance matrixes are performed on received data of an electric dipole and a magnetic dipole respectively and adding summation is performed, a covariance matrix sum only containing an information source azimuth parameter is obtained, a sparse signal reconstruction method is utilized to estimate the information source incident azimuth; and the estimation of polarization parameters is obtained by utilizing maxtrix relations of autocovariance and cross covariance of an electric dipole array and a magnetic dipole array. According to the method, the joint estimation of multi-dimensional parameters is converted into substep estimation of a plurality of one-dimensional parameters, the calculation complexity of the method is lowered; by distributed placing of electric dipole and magnetic dipole sensors, not only is the cross coupling influence between array elements reduced, but also the array physical pore diameter is extended effectively, and the parameter estimation accuracy is improved greatly.

The invention discloses a direction-of-arrival estimation method based on a coprime-type L-type electromagnetic vector sensor array, mainly to solve the problems of serious electromagnetic component mutual coupling and low angle measurement precision of the electromagnetic vector sensor array in the prior art. The realization process comprises steps: 1) a coprime-type L-type electromagnetic vectorsensor array is constructed; 2) a receiving data model of target signals is built, and a signal subspace matrix of the array is calculated; 3) the ambiguous direction cosine estimation values for thetarget signals by two sparse scalar uniform linear subarrays are calculated; 4) an ambiguous direction cosine estimation value for the target signals by a triangular electromagnetic vector sensor iscalculated; and 5) the target signal direction cosine estimation value is subjected to ambiguity resolution, and a two-dimensional spatial direction of arrival of the target is obtained. The sparse scalar uniform linear array is adopted, the pore size is larger, the angle measurement precision is higher, phase centers of an electric dipole and a magnetic ring are separated, mutual coupling betweenreceiving signal electromagnetic components is reduced, and the method can be used for angle positioning on the target by a radar.

The invention discloses a two-dimensional AoA (Angle of Arrival) estimation method based on a separate electromagnetic vector sensor array. The two-dimensional AoA estimation method based on the separate electromagnetic vector sensor array is mainly used for solving the problem that the two-dimensional AoA estimation accuracy is low in a process that a non-time-domain invariable-rotation target is positioned and tracked by vector sensor arrays. The method comprises the steps: (1) constructing received data of the separate electromagnetic vector sensor array; (2) carrying out eigenvalue decomposition on the received data so as to obtain signal subspaces; (3) aiming at the signal subspaces, obtaining a first-dimension ambiguous direction-cosine fine estimate by using space-domain rotation invariance; (4) obtaining an unambiguous direction-cosine rough estimate by using a vector cross multiplication method; (5) obtaining a second-dimension ambiguous direction-cosine fine estimate by using a phase interference method; and (6) obtaining a two-dimensional AoA estimate through combining ambiguous direction-cosine fine estimates and the unambiguous direction-cosine rough estimate. The method has the advantage that the two-dimensional AoA estimation accuracy of the non-time-domain invariable-rotation target is increased greatly and can be applied to the precise positioning and tracking of targets by using radar.

The invention discloses a wave arrival direction estimation method based on an L-shaped electromagnetic vector sensor array, which mainly solves the problem that the mutual coupling is large and the parameter estimation precision is not consistent in a two-dimensional wave arrival direction estimation method of an existing nested array, and the realization steps are as follows: (1) constructing anL-shaped electromagnetic vector sensor array; (2) establishing a received data model of a target signal; (3) calculating the signal subspace matrix of the array; (4) calculating the cosine estimationvalue of the L-shaped array on the target signal; (5) calculating a fuzzy direction cosine estimation value of a single split electromagnetic vector sensor for a target signal; (6) calculating the cosine estimation value of the target signal direction after de-blurring; (7) obtaining the two-dimensional wave arrival direction of the target. According to the invention, the two-dimensional wave arrival direction estimation of the L-shaped electromagnetic vector sensor array is realized, and the method can be used for target positioning in radar and communication.

The invention relates to a UAV (unmanned aerial vehicle) group mounted polarization array attitude measurement and target detection method, and the invention reveals the change rule between the attitude position of a multi-loss electromagnetic vector sensor and the receiving of signals, and achieves the attitude measurement of a platform according to the signals of a plurality of earth satellite navigation systems which achieves the cooperative navigation or the spectrum of a UAV base station signal and maximization. A feature value algorithm is employed for calculating a general electromagnetic wave generalized spatial spectrum, and the polarization signal of a blind signal, the position of a plane, and the frequency shift information are obtained. The installation attitude and position information of a sensor in a plane body is maintained, and the method achieves the multi-target DOA under the conditions that the position of a UAV is not accurate and there is the frequency shift problem.

The invention discloses a direction of arrival estimation method based on a nested electromagnetic vector sensor array, and mainly solves the problems that mutual coupling between each electromagneticcomponent of the electromagnetic vector sensor array is more serious and hardware implementation of the electromagnetic vector sensor array is complicated. The implementation process comprises the steps of constructing a nested electromagnetic vector sensor array; obtaining fuzzy estimates of a target direction cosine using ESPRIT algorithm; pairing fuzzy estimation values of the target directioncosine; obtaining no fuzzy estimation values of the target direction cosine using a vector cross product algorithm of a single separated electromagnetic vector sensor; conducting fuzzy resolution onthe fuzzy estimation values of the target direction cosine, conducting trigonometric operations, and obtaining two-dimensional direction of arrival estimation values of a spatial target. According tothe direction of arrival estimation method based on the nested electromagnetic vector sensor array, the complexity of the mutual coupling and hardware implementation between various electromagnetic components is reduced, the aperture of the whole array is expanded, the accuracy of angle measurement is improved, and the method can be used for angle positioning of a target by a radar.

The invention relates to a decoherence ESPRIT parameter estimation method of an L type electromagnetic vector sensor array. The array receives K coherent narrow-band stable far-field electromagnetic wave signals, and a reception array obtains synchronous sampling data for N times; six subarray data corresponding to an electric dipole subarray and a magnetic dipole subarray of coordinates x, y and z is extracted; a subarray data covariance matrix processes and recovers a rank of a data covariance matrix, and a data covariance matrix after decoherence is obtained; characteristic decomposition is carried out on the data covariance matrix after decoherence to obtain a signal subspace, and the signal subspace is divided into blocks according to structural characteristics of the array; the divided signal subspace is used to estimate a rotation invariant relation matrix in directions x and v; and cosines in directions of axes x and y are obtained, and paired cosines are used to estimate a 2D arrival angle. According to the invention, decoherence is carried out by utilizing a rotation invarirance of the electromagnetic vector sensor subarray, the disadvantage of aperture loss is avoided, a parameter pairing method is simple and effective, and a parameter estimating precision is high.

An electromagnetic vector sensor (EMVS) system, having a plurality of EMVS devices consisting of a plurality of loop antenna elements spatially orthogonally integrated with and electrically isolated from a plurality of dipole antenna elements, mounted on a rotatably adjustable platform having a true north orientation, including active circuitry residing in antenna housings, and external executing software programs causing the active circuitry in cooperation with the EMVS device and receivers to determine angle of arrival and resolution of incoming wave vectors and polarization of incoming signals and to perform accurate high frequency geolocation signal processing; the programs which perform calibration and antenna element placement determination operations, also cause the system to collect data of known transmitted high frequency skywave signals, and estimate direction of arrival of unknown signals by detecting, resolving and measuring components of an electric field and a magnetic field at a single point.

The invention provides a co-prime array coherent signal arrival angle estimation method based on an electromagnetic vector sensor and mainly solves a problem of information loss caused by holes in virtual arrays of co-prime arrays and estimation of coherent sources in a method in the prior art. The method is characterized in that an electromagnetic vector sensor co-prime array is constructed as areceiving array; receiving data of the electromagnetic vector sensor mutual array is divided into six sub-array data, and subarray data covariance matrix vectorization and de-redundancy are performed;receiving data of a uniform sub-array virtual array is constructed through filling array elements; a Toeplitz covariance matrix of a receiving signal of the uniform sub-array virtual array is solved;de-coherent full-rank Toeplitz matrices are obtained by arithmetic averaging, feature decomposition is performed, and the MUSIC method is utilized to estimate the angle of arrival of the signal. Themethod is advantaged in that angle of arrival estimation of the coherent signal can be achieved if the number of signal sources is greater than the number of physical array elements, and estimation accuracy and the estimated number of arrival angles are improved.

The invention relates to an electromagnetic vector sensor array space rotation decoherence direction finding method. An electromagnetic vector sensor linear array is randomly distributed on an x axis to receive K coherent narrowband steady far-field electromagnetic wave signals, and N-order synchronization sampling data is acquired by the array; self orthogonal vector characteristics of the electromagnetic vector sensor array are utilized, electromagnetic vector sensor array data is divided into 6 subarray data, according to subarray space rotation invariable characteristics, a rank of a data covariance matrix is recovered through space rotation decoherence processing to acquire the data covariance matrix after decoherence; a noise subspace is acquired through the data covariance matrix after decoherence, a MUSIC space spectrum is constructed through utilizing the noise subspace, and arrival angle estimation is realized through one-dimensional spectrum peak search of an angle domain. The method is advantaged in that the space rotation decoherence method has no array aperture loss and has a higher spatial resolution compared with a space smooth decoherence method, limit that the space smooth decoherence method is only applicable to uniform arrays is broken, and the space rotation decoherence method is applicable to uniform and non-uniform arrays.

The invention discloses a broadband coherent source positioning method for an electromagnetic vector sensor array, and the method comprises the steps: receiving K far field, coherent and broadband electromagnetic signals through a uniform six-component electromagnetic vector sensor linear array; enabling six channels to perform the Fourier transform to obtain a plurality of broadband coherent signals, wherein the six channels at each frequency point to have the rotation invariant relation; performing the mean decoherent operation through the receiving signal data correlation matrix of the sixchannels; employing MUSIC spectrum peak for searching to obtain AOA (angle of arrival) estimated values at all frequency points, wherein the AOA estimated value of each signal is obtained through thearithmetic averaging of the AOA estimated value at all frequency points. The method enables the broadband signal to be converted into a plurality of narrow band signals through the Fourier transform,and then achieves the decoherent operation via vector rotation through the vector characteristics of an electromagnetic vector sensor, so there is no array aperture loss. The method improves the parameter estimation precision through the arithmetic averaging of the AOAs at all frequency points, and can effectively estimate the AOA of a broadband coherent source.

Provided is a decoherence two-dimensional MUSIC parameter estimation method of an electromagnetic vector sensor array. The method includes: an L-shape array receives K far-field narrowband coherent signals and obtains synchronization data for N times by employing a reception array; respectively extracting data of 6 sub-arrays of electric dipoles in the directions of the x-axis, the y-axis, and the z-axis and magnetic dipoles in the directions of the x-axis, the y-axis, and the z-axis, and obtaining a cross-covariance data matrix before transformation, after transformation, and before and after transformation through arithmetic mean of a covariance matrix of the sub-array data by employing the spatial rotation invariant characteristic of the sub-arrays; obtaining a data covariance matrix after decoherence through covariance matrixes before transformation, after transformation, and before and after transformation to recover the rank of the data covariance matrixes; and performing singular value decomposition on the data covariance matrixes after decoherence to obtain a signal subspace and a noise subspace, constructing a MUSIC spatial spectrum by employing the noise subspace, and accomplishing estimation of two-dimensional direction of arrival through spectrum peak search. The method can be applied to uniform arrays and non-uniform arrays, the loss of array aperture is avoided, the spectrum peak is sharp, and the spatial resolution is high.

The invention relates to an MIMO-Y type antenna array forming method based on electromagnetic vector sensors. The method includes the steps of firstly, calculating the incidence signal spatial guide vector when a plurality of antennas of a receiving end are in a Y type array; secondly, calculating the Y type array guide vector based on the electromagnetic vector sensors; thirdly, calculating the Y type array space fading relevancy function; fourthly, calculating the space fading relevancy when array elements of the Y type array are electromagnetic vector sensor units. By introducing the algorithm of the electromagnetic vector sensors (EVSs) into the Y type antenna array, system modeling for the MIMO is expanded, and the antenna design of an MIMO multi-antenna system terminal is optimized.

The invention provides a transformer bushing insulation partial discharge monitoring system and method. The method comprises the following steps of: sending out a discharge signal by a partial discharge source; sending out an ultrahigh-frequency electromagnetic wave signal by an ultrahigh-frequency sensor, and combining the ultrahigh-frequency electromagnetic wave signal with an ultrasonic signalsent by an ultrasonic sensor as auxiliary judgment signals; denoising a partial discharge signal, extracting an accurate partial discharge signal capable of reflecting a partial discharge problem in atransformer, and further extracting characteristic parameter information in the partial discharge signal; and finally, detecting a high-frequency current signal of a high-frequency current sensor, and judging whether a partial discharge signal exists in an internal insulation system of the transformer or not in combination with the ultrasonic signal sent by the ultrasonic sensor. According to theinvention, an electromagnetic vector sensor and an acousto-optic signal characteristic transformer partial discharge fault detection and positioning technology are utilized to establish a transformerpartial discharge detection method by combining inspection general measurement and accurate determination phase positioning.

The invention discloses an electromagnetic vector sensor array-based anti-independent saturated interference communication method and belongs to the communication, signal analysis, parameter estimation and electronic confrontation field. With the electromagnetic vector sensor array-based anti-independent saturated interference communication method adopted, anti-saturated interference beams can be formed, and anti-interference communication can be realized. The method of the invention includes the following steps that: desired signals are sent by communication base stations in a plurality of different sites, wherein the desired signals are coherent signals; an electromagnetic vector sensor array is adopted as a receiving end, the high-order cumulant of received data is calculated, independent interference is filtered out through using a characteristic that the electric field steering vector of independent signals is perpendicular to the electromagnetic steering vector of the independent signals, so that the estimated value of the direction vector of the desired signals and a signal source position are obtained; and a weight vector is calculated according to a beamforming criterion, anti-interference beams are formed, anti-interference communication is realized, and whether signals are spoof signals can be detected according to the signal source position. The electromagnetic vector sensor array-based anti-independent saturated interference communication method of the invention is applicable to the anti-independent saturated interference communication technologies of aircrafts such as an unmanned aerial vehicle.

The invention proposes an electromagnetic vector-sensor linear array de-coherent multiple signal classification (MUSIC) parameter estimating method. M electromagnetic vector-sensor linear arrays distributed randomly on the y axis receive K coherent narrow bands and the electromagnetic signals of a stable far-field; the arrays obtain synchronous sampling data for N times; according to the rotation invariant feature of the sub-matrixes, the data covariance matrixes before and after the transform and the data covariance matrixes before and after the transform are obtained; based on the data covariance matrixes before and after the transform, the data covariance matrix after the de-coherent is obtained; singular value decomposition is performed to the data covariance matrix after the de-coherent to obtain the signal subspace and noise subspace; the noise subspace is used to construct the MUSIC spatial spectrum; and through the one-dimensional MUSIC spectrum peak, the arrival angle is searched and obtained. The method of the invention is combined with the use of space rotation de-coherent and the thought of the smooth sliding of a previous and after item, which means that on the premise of no loss of the array aperture, the precision of parameter estimation is increased greatly, and the method holds true for both uniform and non-uniform linear arrays.

The embodiment of the invention discloses an electromagnetic vector sensor array element attitude and position six-dimensional error correction method, and relates to the field of signal analysis and parameter estimation. A MUSIC algorithm for polarized array DOA estimation can reduce the number of parameters needing to be searched based on the multi-linear relationship of data. Complete electromagnetic information received by an electromagnetic vector sensor under a reference attitude at a single position in a space can be converted into a received signal under any attitude. By use of a polarized array received data multidimensional linear structure, a polarization domain MUSIC algorithm is applicable to frequency-hopping and broadband signals. There is no need for a special calibration signal source. During use of the system, a reference signal is obtained, and the position error parameters of sensors are obtained. The system realizes automatic correction of the six-dimensional space parameter error of array elements. Under the condition of using multiple single-frequency signal sources, a multi-electromagnetic-vector-sensor array is synthesized from single electromagnetic vector sensors by means of quick and slow sampling. The six-dimensional parameters of attitude and position of an aircraft can be measured by mounting the single electromagnetic vector sensors on the aircraft.