Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

30 results about "Spectral function" patented technology

Low-redundancy high-order direction finding method and system based on co-prime characteristics, and computer storage medium

The invention discloses a low-redundancy high-order direction finding method and system based on co-prime characteristics and a computer storage medium, and the method comprises the steps: receiving signals from a plurality of signal sources through employing a low-redundancy array obtained through improvement based on a co-prime array, and obtaining a received signal; calculating a fourth-order cumulant matrix of the received signal according to the received signal; obtaining a covariance matrix according to the fourth-order cumulant matrix; according to the covariance matrix, calculating to obtain a characteristic value and a characteristic vector of the covariance matrix; dividing the feature vector into a signal subspace and a noise subspace according to the size of the feature value; constructing a spectral function according to the projection of the steering vector on the noise subspace; and searching peak values of the spectral function in all possible directions, and determining the direction of the signal source. According to the low-redundancy array obtained based on improvement of the co-prime array, on the basis that the number of receiving array elements is reduced, the number of estimated signal sources is increased, the fourth-order cumulant is adopted, and the positioning precision in a non-Gaussian noise environment can be improved.
Owner:GUANGDONG UNIV OF TECH

Chirp grating design method and device, equipment and storage medium

The invention discloses a chirp grating design method and device, equipment and a storage medium, and relates to the technical field of optical fibers, and the disclosed chirp grating design method comprises the steps: analyzing a preset target spectrum function to obtain a target grating structure parameter; layering the initial grating into a plurality of sub-grating regions with uniform periods based on the target grating structure parameters, and establishing a layered transmission matrix model; determining a refractive index modulation depth range of each sub-gate region according to the layered transmission matrix model; and performing iterative optimization on grating structure parameters of the initial grating according to the layered transmission matrix model, the target spectral function, the refractive index modulation depth range and a preset error function to obtain a target grating. The performance of the chirp grating can be optimized.
Owner:WUHAN RAYCUS FIBER LASER TECHNOLOGY CO LTD

Forward modeling method for multidirectional sea wave induction electromagnetic field

The invention discloses a forward modeling simulation method for a multidirectional sea wave induction electromagnetic field. The method comprises the following steps: expressing energy distribution of different propagation directions and frequency components through a spectral function; setting external environment input required by forward modeling according to the seawater depth and geomagnetic field parameters of the research area; after parameter setting is completed, electromagnetic response calculation is carried out on each frequency-direction sampling point; component response is called on a preset frequency set and a preset direction set, linear superposition is carried out by adopting a frequency direction correspondence method, and a total electromagnetic field is obtained; and outputting time sequences and frequency spectrum results of the wind wave induction electromagnetic field, the surge induction electromagnetic field and the mixed wave induction electromagnetic field, thereby providing a reference basis for noise analysis, background interference suppression and target signal identification in electromagnetic detection. According to the method, the limitation of a traditional model is broken through, the electromagnetic interference characteristics under the complex sea condition are represented more truly, and reliable support is provided for noise suppression and target recognition in electromagnetic detection.
Owner:OCEAN UNIV OF CHINA

Passive positioning method based on Wi-Fi beam forming feedback information

The invention provides a passive positioning method based on a wireless fidelity (Wi-Fi) beam forming feedback information (BFI). The passive positioning method comprises the following steps of: firstly, carrying out passive positioning on the basis of the Wi-Fi beam forming feedback information (BFI); the method comprises the following steps: firstly, pre-determining the position of a transceiver, and respectively extracting BFIs of a direct path and a target reflection path of the transceiver; compared with extraction of channel state information (CSI), the BFI is inherent information in a Wi-Fi communication protocol, special acquisition hardware does not need to be additionally deployed, the BFI can be directly extracted from the communication process, the hardware cost and the deployment threshold of a positioning system are greatly reduced, and large-scale popularization and application are easier to realize. And secondly, by constructing a BFI covariance matrix, high-dimensional matrix operation in a traditional MUSIC algorithm is converted into low-dimensional matrix processing, and the calculation complexity is remarkably reduced. And finally, constructing a spectral function to respectively obtain an angle of departure (AOD) of a direct path of the transceiver and a target reflection path and a flight time difference of the two paths, substituting the parameters into the elliptic constraint model for calculation, and finally solving to obtain an estimated position of the target. According to the method designed by the invention, the real-time performance and the deployment flexibility of the system are greatly improved under the condition that the calculation complexity is remarkably reduced and the support of specific hardware is not needed.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

A non-rigid point cloud registration method and storage medium

ActiveCN116681744BImage enhancementImage analysisPoint cloudSpectral function
The application discloses a non-rigid point cloud registration method and a storage medium, and the non-rigid point cloud registration method comprises the following steps: establishing a first neural network for generating a high-dimensional feature embedding matrix, and training the first neural network according to a first target, wherein the first target is to make the Euclidean distance between each two high-dimensional feature embeddings in the generated high-dimensional feature embedding matrix equal to the geodesic distance of the corresponding two points in the input point cloud; establishing a second neural network for generating a high-dimensional feature descriptor matrix, and training the second neural network based on the high-dimensional feature embedding matrix; inputting two point clouds to be registered into the trained first neural network and second neural network to obtain two high-dimensional feature embedding matrices and two high-dimensional feature descriptor matrices; further calculating a spectral function mapping, and then calculating a corresponding relationship mapping of the two point clouds to be registered. The application not only improves the calculation efficiency, but also has robustness in processing noise and various incompleteness.
Owner:TSINGHUA SHENZHEN INTERNATIONAL GRADUATE SCHOOL

A profiling control method, device and storage medium for a harvesting machine header

The present application relates to a method, device and storage medium for contour following control of a harvesting machine header. The method includes the steps of: obtaining geographical information of a target plot; generating a ground spectral function of the target plot according to the geographical information; obtaining initial motion data of the harvesting machine; generating virtual operation parameters of the harvesting machine according to the initial motion data; obtaining real-time motion data of the harvesting machine; and adjusting the real-time motion data in real time according to the virtual operation parameters. The method, device and storage medium for contour following control of a harvesting machine header provided by the embodiments of the present application can adjust control parameters according to the traveling speed of the harvesting machine to ensure that the header will not respond too slowly during high-speed movement or overshoot too much during low-speed movement.
Owner:LOVOL HEAVY IND CO LTD

Low-redundancy high-order direction-of-arrival measurement method and system based on co-prime characteristics and computer storage medium

The application discloses a low-redundancy high-order measurement direction method and system based on the coprime characteristic and a computer storage medium, and the method comprises the following steps: receiving signals from multiple signal sources by using a low-redundancy array improved based on a coprime array to obtain received signals; calculating a fourth-order cumulant matrix of the received signals according to the received signals; obtaining a covariance matrix according to the fourth-order cumulant matrix; calculating eigenvalues and eigenvectors of the covariance matrix according to the covariance matrix; dividing the eigenvectors into a signal subspace and a noise subspace according to the sizes of the eigenvalues; constructing a spectral function according to projections of the steering vectors on the noise subspace; searching for peak values of the spectral function in all possible directions to determine the directions of the signal sources. The low-redundancy array improved based on the coprime array can not only expand the estimated number of signal sources on the basis of reducing the number of received array elements, but also adopt the fourth-order cumulant, so that the positioning precision in a non-Gaussian noise environment can be improved.
Owner:GUANGDONG UNIV OF TECH

A sound vector array DOA estimation method based on quaternion matrix dimension reduction

The purpose of this invention is to provide a method for DOA estimation of acoustic vector arrays based on quaternion matrix dimensionality reduction, comprising the following steps: constructing a CAACIS acoustic vector coprime array at the receiver; establishing a quaternion model of the received signal based on the array output; estimating the quaternion covariance matrix; performing dimensionality reduction on the quaternion covariance matrix to obtain a virtual array received signal model of the acoustic vector coprime array; reconstructing the Hermitian-Toeplitz matrix; performing eigenvalue decomposition on the Hermitian-Toeplitz matrix and constructing a spatial spectral function; and obtaining the DOA estimation result through spectral peak search. This invention addresses the problem of how to achieve multi-objective DOA estimation with both low complexity and good performance based on a quaternion framework under acoustic vector coprime arrays.
Owner:HARBIN ENG UNIV

A method for calculating lattice thermal conductivity of rare earth oxides based on first principle

The application discloses a method for calculating lattice thermal conductivity of rare earth oxide based on first principle. The method comprises the following steps: establishing a crystal structure model of the rare earth oxide, and constructing a supercell model after structure optimization; calculating second-order interatomic force constants by using a first principle method to obtain a phonon dispersion relation, and calculating third-order interatomic force constants to obtain a phonon scattering rate; solving the lattice thermal conductivity by using a Wigner transport equation, wherein the lattice thermal conductivity comprises a particle contribution described by a diagonal item of a phonon spectral function and a wave contribution described by a non-diagonal item, and the two are added to obtain a thermal conductivity contribution of each phonon mode; and integrating and summing all phonon modes in a Brillouin zone to output a frequency, temperature and direction dependence of the total lattice thermal conductivity. The application can accurately predict the lattice thermal conductivity and anisotropy of the rare earth oxide in a wide temperature range without an empirical parameter.
Owner:SHANGHAI UNIV

Method and device for multi-target super-resolution positioning by frequency-modulated continuous wave radar

A method and apparatus for super-resolution localization of multiple targets using frequency-modulated continuous wave radar includes: determining the number K of targets based on the number of eigenvalues ​​satisfying a condition in the covariance matrix of the acquired radar array signal; finding the frequency values ​​corresponding to the K largest spectral peaks based on the acquired number of targets K, using these frequency values ​​as coarsely estimated intermediate frequency (IF) values, and determining the final IF value using the coarsely estimated IF values; calculating the distance of the corresponding target relative to the center O of the antenna array based on the final IF value; obtaining the noise subspace of the array signal and the steering vector related to the target distance and angle based on the eigenvalues ​​of the covariance matrix of the array signal, constructing a MUSIC spectral function, and determining the estimated value of the target echo signal direction; and then determining the position of the corresponding target. This invention has higher range and angle resolution and lower algorithm complexity, enabling super-resolution localization of multiple targets.
Owner:NAT UNIV OF DEFENSE TECH

A DOA estimation method based on reorganized nested arrays

ActiveCN114035148BDirection findersComplex mathematical operationsNested arraysSpectral function
This invention discloses a direction-of-arrival (DOA) estimation method based on a reorganized nested array configuration. The method comprises the following steps: reordering two subarrays of a nested array to construct a reorganized nested array configuration; calculating the differential co-array and its maximum continuous degree of freedom of the reorganized nested array; spatially sampling the target radiator based on the reorganized nested array and vectorizing the covariance matrix of the antenna array's received signal; reconstructing the incident signal components based on a compressed sensing method; and constructing a spectral function and performing a spectral peak search to estimate the DOA of the target radiator. The invention proposes a differential co-array with a hole-free characteristic in the reorganized nested array configuration, which expands the array's degrees of freedom and effective array aperture, enabling high-precision underdetermined DOA estimation.
Owner:JINLING INST OF TECH

Frequency super-resolution time-frequency analysis method based on eigenvalue decomposition

The invention belongs to the field of digital signal time-frequency analysis, and provides a frequency super-resolution time-frequency analysis method based on eigenvalue decomposition, which comprises the steps of intercepting a signal sequence along a time axis, constructing a virtual matrix, carrying out eigendecomposition on a covariance matrix, constructing a noise matrix, calculating pseudo-spectrum functions and combining the pseudo-spectrum functions along the time axis to form a time-frequency graph. The method does not depend on the number of time domain sampling points, geometric structure information of signals is extracted through subspace decomposition insensitive to noise, limitation of an STFT time window is broken through, high-frequency resolution can still be achieved under the condition of a short window, the time-frequency contradiction problem of STFT is relieved, and the method has the advantages of being simple in structure and convenient to operate. And a new technical approach is provided for accurate detection and parameter extraction of non-cooperative signals in an optical down-conversion electric field measurement system.
Owner:BEIHANG UNIV

Wave direction angle analysis method and equipment

The invention discloses a wave direction angle analysis method and equipment, and belongs to the field of wave test simulation. The method comprises the following steps: 1) generating a target area wave height data array; 2) performing forward and backward smoothing on the wave height data array of the target area to obtain a doubled data array; 3) calculating a covariance matrix of the doubled data array; 4) calculating an optimized covariance matrix by using a spatial smoothing method; 5) calculating all eigenvalues and eigenvectors of the optimized covariance matrix; 6) arranging according to the sizes of the characteristic values, distinguishing signal subspaces / noise subspaces, and constructing a noise matrix; 7) performing translation and reciprocal weighting processing on the characteristic value of the noise subspace to obtain a weighted noise matrix; 8) constructing a spectral function by using an orthogonal relationship between the wave steering vector and the weighted noise matrix, and 9) calculating the spectral function corresponding to all angles, wherein the angle corresponding to the peak value of the spectral function is the oblique wave direction estimation angle.The method can quickly and accurately calculate the wave field direction angle in real time.
Owner:DALIAN UNIV OF TECH

Method and device for rapidly extracting moire fringe alignment deviation based on graphics processor

The invention provides a method, a device and equipment for rapidly extracting a moire fringe alignment deviation based on a graphics processor, and the method comprises the steps: receiving two groups of moire fringe signals which are obtained by analyzing two groups of moire fringe patterns representing an alignment state; performing parallel collaborative fast Fourier transform on the two groups of moire fringe signals by using a graphics processor to respectively obtain frequency domain representations corresponding to the two groups of moire fringe signals; calculating to obtain a frequency spectrum function representing the phase deviation of the two groups of moire fringe signals based on the two groups of frequency domain representations by using a graphics processor; wherein the frequency spectrum function is used for determining the phase deviation between the two groups of moire fringe signals, and the phase deviation is used for representing the alignment deviation.
Owner:INST OF OPTICS & ELECTRONICS CHINESE ACAD OF SCI

Unmanned aerial vehicle monitoring method based on extended Kalman filter and MUSIC algorithm

The invention discloses an unmanned aerial vehicle monitoring method based on an extended Kalman filter and a MUSIC algorithm, and the method comprises the steps: a data center processes an echo signal through the MUSIC algorithm, obtains a spectral function, uniformly takes a plurality of angle values in a search window, and substitutes the angle values into a spectral function curve, and the angle value spacing is a step length; finding out a candidate peak in the spectral function curve and matching the candidate peak with the unmanned aerial vehicle, wherein a direction angle of the candidate peak is a measurement azimuth angle of the matched unmanned aerial vehicle; and then, based on the EKF in combination with the measured azimuth angle, obtaining the state vector of the unmanned aerial vehicle, and fitting the flight path of the unmanned aerial vehicle according to the state vectors at multiple moments. The search window and the step length at each moment can be adjusted for spectral function curve fitting at the next moment. According to the search window and the step length dynamically adjusted according to the target state, the accuracy of the result is improved on the premise of controlling the calculation amount; according to the method, a plurality of maximum values in the curve can be processed, and track aliasing is effectively avoided; a result is obtained through EKF, noise influence is reduced, and authenticity is guaranteed.
Owner:HOHAI UNIV

Sleep and emotion regulation control method and system based on specific spectrum function

The invention provides a sleep and emotion regulation control method and system based on a specific spectrum function, and belongs to the technical field of medical equipment.The method specifically comprises the steps that a user is regulated and controlled according to regulation and control user data and in combination with the consistent degree of sleep feature signals of the user in the light sleep stage, and the sleep state of the user is adjusted and controlled; the method comprises the following steps: determining a stopping control method for sleep and emotion regulation and control processing with a specific spectrum function, carrying out stopping control processing on a regulation and control user based on the stopping control method, and according to stopping control data of the regulation and control user, when determining that personalized sleep staging model construction processing needs to be carried out, according to the stopping control data of the regulation and control user, establishing a personalized sleep staging model according to the stopping control data of the regulation and control user. According to the method, the pause matching condition of the regulation and control user is determined, the construction processing target of the personalized sleep staging model is determined based on the pause matching condition and the stability condition of the sleep feature signal, and the reliability degree in the sleep and emotion regulation and control process based on the specific spectrum function is improved.
Owner:松研科技(杭州)有限公司

A sleep and mood regulation control method and system based on specific spectral function

The application provides a sleep and emotion regulation control method and system based on specific spectral function, and belongs to the technical field of medical devices, and specifically comprises the following steps: according to the regulation and control user data, and in combination with the consistency degree of the sleep characteristic signal of the regulation and control user in the light sleep stage, the regulation and control user is regulated and controlled, the determination of the suspension control method of the sleep and emotion regulation processing of the specific spectral function is adopted, the suspension control processing of the regulation and control user is carried out based on the suspension control method, according to the suspension control data of the regulation and control user, when it is determined that the construction processing of the personalized sleep staging model needs to be carried out, according to the suspension control data of the regulation and control user, the suspension matching condition of the regulation and control user is determined, based on the suspension matching condition and the stability condition of the sleep characteristic signal, the determination of the construction processing target of the personalized sleep staging model is carried out, and the reliability in the sleep and emotion regulation control process based on the specific spectral function is improved.
Owner:松研科技(杭州)有限公司

A method for enhancing the line spectrum of moving targets based on elite selection genetic algorithm

PendingCN122286445AFrequency spectrumAlgorithm
This invention relates to the field of underwater acoustic signal processing technology, and in particular to a method for enhancing the line spectrum of moving targets based on an elite selection genetic algorithm. Based on the Doppler-warping transform, the method utilizes an elite selection genetic algorithm to autonomously optimize and estimate the target's motion parameters. Using the entropy of the transformed target signal's spectral function as the cost function, the optimal motion parameters are searched by comparing the spectral entropy values ​​under different parameters. Then, the optimal parameters are used to perform a Doppler-warping transform on the original signal, refocusing the line spectrum energy dispersed by the Doppler effect near the original frequency, thus achieving autonomous enhancement of the moving target's line spectrum. This invention effectively solves the problems of the inability to accumulate moving target line spectrum energy over long periods and the autonomous search of Doppler-warping transform parameters, improving the probability and accuracy of line spectrum detection. It can be applied to data backtracking and review processing in underwater moving target detection, and has good engineering practical value.
Owner:THE 715TH RES INST OF CHINA SHIPBUILDING IND CORP

A spectrometer based on optical waveguide leaky mode spectroscopy and a spectral reconstruction method thereof

The application discloses a spectrometer based on light waveguide leakage mode light splitting and a spectrum reconstruction method thereof. The spectrometer comprises an image sensor and at least one light waveguide, the surface of the image sensor is coated with a substrate layer, the first end of the light waveguide is connected with a light source as an entrance, and the second end of the light waveguide is adsorbed on the surface of the substrate layer after being heated and drawn. The spectrum reconstruction method comprises the following steps: calibration: the photocurrent value of the sensor unit at each wavelength is saved as a spectral response function; collecting photocurrent: collecting the photocurrent value of the to-be-detected light in any sensor unit; constructing an equation set and solving: obtaining k actual spectral functions of the to-be-detected light, solving the corresponding photocurrent equation and composing a linear equation set, and solving to obtain the reconstructed actual spectral function of the to-be-detected light. The application has the advantages of small physical volume, multi-channel detection and accurate detection result.
Owner:海宁市产业技术研究院

Portable in-situ self-scanning multispectral microscopic spectrum system

The invention relates to a portable in-situ self-scanning multispectral microscopic spectrum system. The system comprises a multispectral microscopic spectrum measurement module, a movable self-supporting structure, a microscopic objective lens assembly and an objective lens scanning mechanism which are integrated; wherein the multispectral microscopic spectrum measurement module is used for realizing excitation and signal acquisition of multiple spectrum modes, and the spectrum modes comprise but are not limited to fluorescence spectrum, Raman spectrum and white light absorption spectrum; the microscope objective assembly is used as a unified in-situ optical interface, so that measurement of different spectrum functions is completed in the same light path and the same space coordinate system; the objective lens scanning mechanism is used for driving the microscope objective lens assembly to perform scanning movement in at least two space directions, so that multispectral space scanning measurement is realized under the condition that a measured object is kept relatively static, and state disturbance and measurement errors caused by moving a sample through an objective table traditionally are avoided; and the movable self-supporting structure is used for quickly deploying and keeping the system stable in different use scenes.
Owner:PUXIANG OPTOELECTRONICS TECHNOLOGY (SHANGHAI) CO LTD

Fusion subspace doa estimation method based on sparse bayesian learning

This invention proposes a fusion subspace DOA estimation method based on sparse Bayesian learning. The implementation steps are as follows: first, an overcomplete steering vector dictionary matrix is ​​constructed, and a sparse representation model is built. Then, the signal is reconstructed using the sparse Bayesian learning algorithm. After obtaining the reconstructed signal, a signal covariance matrix is ​​constructed. Finally, eigenvalue decomposition is performed on the covariance matrix to construct a spatial spectral function, and the peak value of this spectral function is searched across the entire angular range. This invention integrates the SBL algorithm and the MUSIC algorithm. The MUSIC algorithm is used to perform subspace decomposition on the reconstructed covariance matrix, extracting the noise subspace and utilizing its orthogonality with the steering vector, thereby improving the angular resolution of the SBL algorithm. This makes this invention applicable to achieving high-resolution DOA estimation under conditions of few or even single snapshots.
Owner:XIDIAN UNIV +1

Monopole crossed loop antenna signal direction finding method combining amplitude comparison and variable step size MUSIC

The invention relates to a monopole cross loop antenna signal direction finding method combining amplitude comparison and variable step size MUSIC, and the method mainly comprises the steps: obtaining an initial estimation angle through an amplitude comparison algorithm, if the angle is located in a loop antenna cross angle domain, directly taking the angle as a final result through the high-precision characteristic of the amplitude comparison algorithm in the angle domain, and carrying out the direction finding of the monopole cross loop antenna signal. The direction finding performance of the angular domain is improved; and if the spatial spectrum function is not located in the cross angle domain, the spectral peak search range of the MUSIC algorithm is further narrowed by using the initial estimation result, and the spatial spectrum function is searched by adopting a variable step size mode, so that the direction finding resolution of the MUSIC algorithm is improved, and the calculation complexity is reduced at the same time. According to the method, two direction finding algorithms of amplitude comparison and MUSIC are utilized, high-precision direction finding in a loop antenna cross angle domain is realized, a higher resolution success rate is shown, the direction finding efficiency is effectively improved, and the method has important application value in the fields of high-frequency radar ocean current detection, short-wave communication and the like.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Passive positioning method for MIMO-OTFS system

The invention provides a passive positioning method for an MIMO-OTFS system. The method comprises the following steps: establishing communication connection between a transmitting end and a receiving end through a protocol; a transmitting end is used for transmitting signals, and a receiving end receives the signals through a channel tool to obtain original channel state information; performing CP decomposition operation on the original channel state information; performing signal subspace division and noise subspace division on the decomposed tensor in sequence to construct a mapping matrix, designing a spectral function by using the mapping matrix, and performing multipath parameter estimation through spectral peak search operation; and estimating motion attribute information of the target based on the accurately estimated channel parameters in combination with priori information of a perception environment to obtain position estimation and a motion track of the target. The method can effectively deal with a complex multi-path indoor environment, realizes a more accurate position estimation result by using an existing commercial terminal without a large-aperture array, and can greatly improve the robustness of a positioning system.
Owner:HUNAN UNIV

Method of Raman spectrospy

A method includes, with a Raman spectrometer: determining a measured spectrum; determining a second derivative of a difference spectrum function corresponding to a difference between the measured spectrum and a product of a scaling coefficient and a reference spectrum of contributions of interfering influences included in the measured spectrum; determining a coefficient value of the scaling coefficient minimizing an error function including a term corresponding to an error of the difference spectrum function due to peaks included in the reference spectrum, the term including a sum of areas enclosed underneath the second derivative in all spectral regions in which the second derivative is positive, and / or a sum of areas enclosed underneath the second derivative in all spectral regions in which the second derivative is negative; and determining a Raman difference spectrum corresponding to the difference between the measured spectrum and a product of the coefficient value and the reference spectrum.
Owner:ENDRESSHAUSER OPTICAL ANALYSIS INC

Data creation device, data creation method, and data creation program

This improves the efficiency of generating optical pulses for laser processing, which are formed using a spatial light modulator. [Solution] The data creation device 1 is a device for creating data to control an SLM24 that shapes light pulses for laser processing, and comprises: a waveform setting unit 11 which sets information on a plurality of different time-intensity waveforms, each containing a plurality of light pulses; a spectrum design unit 12 which generates a plurality of sets of intensity spectral functions and phase spectral functions based on each of the plurality of time-intensity waveforms; a data generation unit 15 which creates a plurality of data based on each of the plurality of sets of intensity spectral functions and phase spectral functions; and a data determination unit 16 which calculates the generation efficiency of each of the plurality of time-intensity waveforms in the SLM24 based on each of the plurality of data, and determines data to control the SLM24 from the plurality of data based on the generation efficiency.
Owner:HAMAMATSU PHOTONICS KK

An x-ray focusing detection system with a wide spectral range and high spectral resolution

The application discloses a kind of wide spectrum range and high spectral resolution X-ray focusing detection system, for detecting after X-ray diffraction of light source, including diffraction crystal and detector, the surface of the diffraction crystal has diffraction surface, the diffraction surface can be detected by detector after the total diffraction of X-ray emitted and radiated to diffraction surface by the light source;The application solves the technical problems of low X-ray collection efficiency of traditional plane crystal, low X-ray spectrum resolution of cylindrical or conical crystal, narrow spectral range of spherical crystal, so that it has the characteristics of high spectral resolution, high collection efficiency and wide spectral range, so as to realize the focusing spectral function of X-ray at multiple energy points, and weaken the restriction on the placement position of light source in the whole X-ray spectrum detection system.
Owner:CHONGQING UNIV +1

Method and apparatus for analyzing wave direction angle

The application relates to a wave direction angle analysis method and device, belonging to the field of wave test simulation. The specific process comprises the following steps: 1) generating a wave height data array of a target area; 2) performing forward and backward smoothing on the wave height data array of the target area to obtain a doubled data array; 3) calculating a covariance matrix of the doubled data array; 4) calculating an optimized covariance matrix by using a spatial smoothing method; 5) calculating all eigenvalues and eigenvectors of the optimized covariance matrix; 6) arranging the eigenvalues according to the size, distinguishing a signal subspace / noise subspace, and constructing a noise matrix; 7) performing translation and reciprocal weighting processing on the eigenvalues of the noise subspace to obtain a weighted noise matrix; 8) utilizing the orthogonal relationship between a wave guide vector and the weighted noise matrix to construct a spectral function; and 9) calculating the spectral function corresponding to all angles, and the angle corresponding to the peak value of the spectral function is the oblique wave direction estimation angle. The method can quickly and accurately calculate the wave field direction angle in real time.
Owner:DALIAN UNIV OF TECH

A method for measuring real-time flow of industrial pipeline based on MUSIC algorithm

This invention discloses a real-time flow measurement method for industrial pipelines based on the MUSIC algorithm. The method comprises the following steps: Step 1, acquiring fluid flow signals within the pipeline using a multi-sensor array distributed on the outer wall of the pipeline; Step 2, preprocessing the acquired signals, including window function processing and bandpass filtering; Step 3, constructing a robust covariance matrix for the array measurement signals; Step 4, processing the robust covariance matrix to obtain the noise subspace eigenvector matrix Un; Step 5, calculating the MUSIC spectrum, constructing the power spectral function, and calculating the k-f spectrum; Step 6, plotting the energy curve (wavenumber-frequency diagram), and then searching for the optimal flow velocity in the k-f spectrum using the tilt stacking method to calculate and output the real-time flow velocity. This invention significantly improves the accuracy of signal source estimation and measurement precision under low signal-to-noise ratio conditions.
Owner:HUNAN UNIV

Two-dimensional DOA estimation method based on Capon dimensionality reduction for mutually prime arrays

The present invention discloses a dimensionality-reduced Capon algorithm for two-dimensional DOA estimation of multiple signals using a coprime array. The algorithm first calculates the covariance matrix of the received signal, then reduces the two-dimensional spectral function to one dimension. Leveraging the linear relationship between true and fuzzy DOA estimates, a one-dimensional partial spectrum search is performed on a local region to obtain a fuzzy DOA estimate that correlates with the theoretical DOA, significantly reducing computational complexity. Finally, based on the properties of the coprime array, a true DOA estimate is obtained. Compared to the traditional coprime array two-dimensional Capon algorithm, this method achieves nearly identical DOA estimation performance while avoiding the significant computational complexity associated with a two-dimensional spectral peak search.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

A method and system for amplitude control of frequency domain controllable source electromagnetic transmit pulses

The present application relates to the technical field of geophysical environment exploration, and specifically discloses a frequency-domain controllable source electromagnetic emission pulse amplitude control method and system, the method comprising constructing a pseudo-random pulse sequence basic framework and an exploration target adaptive spectral function curve according to exploration requirements; in the basic framework, the lowest frequency of each basic unit adopts adaptive frequency error design, and the basic unit is composed of a series of sine waves with different frequencies; the pseudo-random pulse sequence is subjected to frequency spectrum ratio-based iterative amplitude adjustment, so that the frequency spectrum amplitude approximates the expected spectral function curve; the time domain waveform of the amplitude-adjusted pseudo-random pulse sequence is subjected to amplitude limiting to generate a bipolar pseudo-random pulse; the present application realizes combination of different frequency point amplitudes by nonlinear control of emission pulse spectral distribution, improves measurement precision, and expands the emission pulse excitation range.
Owner:JILIN UNIVERSITY