26results about How to "Improve direction finding accuracy" patented technology

The invention belongs to but is not limited to the technical field of radio detection direction finding, and discloses a double-antenna three-dimensional rotating baseline direction finding method, device and system. Inter-channel phase deviation table compensation is carried out, equal-frequency-interval full-working-frequency-band measurement is carried out on phase deviation between two measurement channels in advance, and a channel phase deviation compensation table AB is formed; the compensation module is used for compensating inherent phase deviation between the channel A and the channel B; after the double-antenna three-dimensional rotating baseline direction finding device starts to work, a baseline formed by the antennas AB rotates anticlockwise at an angular velocity omega, two receiving channels synchronously collect data, and phase difference is calculated for the data corresponding to the baselines AB; based on a two-dimensional joint search method, through combination of coarse search and fine search, an azimuth angle and a pitch angle are estimated. According to the technical scheme provided by the invention, the direction finding range and reliability of a traditional system are greatly expanded, meanwhile, the cost is basically not increased, and the large-scale application of the technical system can be promoted.

The invention discloses an ultra-short wave signal reconnaissance and direction finding positioning system and method based on an unmanned aerial vehicle in the technical field of radio signal reconnaissance and direction finding. The system comprises an unmanned aerial vehicle platform, a broadband direction-finding antenna array, a reconnaissance direction-finding load and a ground remote control terminal, wherein the broadband direction-finding antenna array and the reconnaissance direction-finding load are both arranged on the unmanned aerial vehicle platform; the broadband direction-finding antenna array comprises two independent broadband omnidirectional receiving antennas and outputs received signals to the reconnaissance direction-finding load; the reconnaissance direction-finding load comprises an acquisition preprocessing unit and a signal processing unit; the output end of the broadband direction-finding antenna array is connected with the acquisition preprocessing unit, and the acquisition preprocessing unit sends a preprocessing result to the signal processing unit; the ground remote control terminal comprises a load display control module and a flight control module; the load display control module is responsible for issuing a task instruction and receiving reconnaissance information uploaded by the reconnaissance direction-finding load at the same time. The method has the advantages of light weight, low power consumption and no need of regular calibration.

The invention discloses a double-seabed horizontal array joint target positioning method based on subspace intersection, and the method comprises the steps: synchronously collecting signals transmitted by an underwater sound source through two seabed horizontal arrays, and constructing a signal receiving model; establishing a two-dimensional rectangular coordinate system based on the spatial positions of the two seabed horizontal arrays; in the sea area where the two seabed horizontal arrays are located, acoustic environment parameters are measured; based on a modal theory, substituting the acoustic environment parameters into the normal wave model, and calculating the horizontal wave number of each order of normal wave in the sound field; screening out an effective mode in each order mode corresponding to the horizontal wave number; constructing a covariance matrix of a horizontal array output signal; performing eigenvalue decomposition on the covariance matrix to construct a signal subspace; constructing a modal subspace; the modal subspace and the signal subspace are combined and orthogonal triangular decomposition is carried out so as to solve the estimation result of the two seabed horizontal arrays on the sound source azimuth angle; and estimating the position of the sound source according to the estimation result of the two seabed horizontal arrays on the azimuth angle of the sound source.

The invention discloses a rotation-based channel mismatch calibration and correlation interferometer direction finding method in the technical field of radio direction finding. The rotation-based channel mismatch calibration and correlation interferometer direction finding method comprises the following steps: flow steps of the rotation-based channel mismatch calibration and correlation interferometer direction finding method; the performance of the correlation interferometer direction finding method is verified through analog simulation, and the performance of the correlation interferometer direction finding method is evaluated on the basis that a data set is collected in a microwave anechoic chamber. According to the rotation-based channel mismatch calibration and correlation interferometer direction-finding method, an ideal channel mismatch correction effect can be achieved, a phase difference sample library is constructed by using numerical calculation on the basis, and the efficiency and the direction-finding precision of a direction-finding system are improved.

The invention belongs to but not limited to the technical field of radio detection, and particularly relates to a three-dimensional rotating baseline direction finding method, system, equipment, medium and terminal, the system is composed of three antennas which are respectively marked as an antenna A, an antenna B and an antenna C. The antenna A and the antenna B form a linear array which is connected through a cross rod, the distance is adjustable, the maximum is X m, and the midpoint of the A and B linear arrays is the position of a rotating shaft; a vertical rod is arranged at the center of the AB along a rotating shaft, the length of the vertical rod is adjustable, the longest length is Y meters, and the antenna C is located at the upper end of the vertical rod. During working, a base line where the antenna AB is located is driven by the rotating mechanism or the rotating platform to rotate anticlockwise, and the antenna C is located on the rotating shaft and does not rotate; the three antennas are respectively connected to the three receiving channels and synchronously start to collect data during working to form a base line AB, a base line AC and a base line BC, and phase differences of the base line AC, the base line BC and the base line AC are measured.

The invention provides a low-delay wave beam direction finding technology realized based on an FPGA. The low-delay wave beam direction finding technology comprises the following steps: establishing a wave beam direction finding simulation mathematical model according to a wave beam direction finding algorithm in combination with specific hardware parameters and indexes and feature information of a to-be-detected flight target; converting the established wave beam direction finding simulation mathematical model into an FPGA program; the method comprises the following steps: establishing a hardware test platform, and programming an FPGA (Field Programmable Gate Array) program into an FPGA baseband board; and performing operation according to the direction testing process to complete direction testing. Compared with the prior art, the delay caused by direction finding is greatly reduced by virtue of the strong parallel processing capability of the FPGA chip and the high-speed clock, and meanwhile, the resolution of direction discrimination is improved. Through application of the FPGA and accurate mathematical modeling, the method has significant advantages in the aspects of direction finding precision, real-time performance, system expansibility, anti-interference capability and the like, and can effectively cope with complex flight target direction finding tasks. Therefore, the technology has wide application prospects in the fields of aerospace, military reconnaissance, unmanned aerial vehicles and the like.

The present invention proposes an inertial navigation-assisted radio direction finding correction method in a complex environment, which can be used for inertial navigation-assisted radio direction finding correction in long-distance complex aviation search and rescue application scenarios. When the carrier aircraft direction finding equipment is blocked or otherwise interfered with, the airborne position information and heading information output by the inertial navigation are combined with the direction finding information measured by the orientation device, and multi-point direction finding information of a single level flight segment is used to perform cross positioning, and the single positioning accuracy is improved by clustering, and then the global target positioning accuracy is gradually improved by using the measurement information of multiple level flight segments, and the direction finding result is corrected, thereby greatly improving the orientation accuracy and reliability of the aviation search and rescue orientation equipment.

The invention discloses a complex electromagnetic environment direction finding method based on a multi-mode accumulated phase difference method, and belongs to the technical field of radio direction finding. According to the invention, a multi-mode accumulation phase difference method is adopted, the phase difference of each frequency point after FFT transformation is independently calculated, multi-target simultaneous direction finding in a complex electromagnetic environment is realized, the multi-target signal direction finding resolution is improved, thousands of target signals in an analysis bandwidth can be simultaneously subjected to direction finding, and the method is not limited by signal processing path resources of a traditional direction finding method; different characteristic signal types can be adapted through different accumulation modes, and the direction finding capability of complex communication signals is improved; and the direction finding precision and the direction finding sensitivity are improved through a multi-time direction finding result accumulation function.

The application relates to a MUSIC direction-finding method based on an underwater information system cross array, and belongs to the technical field of underwater acoustic direction finding. In view of the problems of low signal-to-noise ratio and low direction-finding precision of underwater signal direction finding, the application provides a MUSIC direction-finding method based on an underwater information system cross array. The method is based on a MUSIC algorithm, frequency extraction and spatial spectrum accumulation, a cross array is used to perform direction-finding processing on a signal, the relative position relationship between the signal and the cross array is obtained, a suitable linear array in the cross array is selected to perform direction-finding processing on the signal, and the direction finding of an underwater target acoustic signal under low signal-to-noise ratio can be effectively realized.

The present invention discloses a weak signal DOA estimation method based on weighted sparse reconstruction. First, the received array data is subjected to dimensionality reduction and optimization processing to obtain a new sparse reconstruction model; secondly, according to the array data, a weight matrix is ​​constructed by combining the phase group delay spectrum with the amplitude spectrum; finally, the weight matrix is ​​combined with the new sparse reconstruction model to perform second-order cone programming to solve the DOA estimation. This method has high resolution and strong robustness when finding the direction of weak signals, a sharp main lobe of the spectrum, lower side lobes, fewer pseudo peaks, and fewer snapshots required, and can accurately and stably estimate the signal arrival direction and improve the system sensitivity. This is conducive to improving the calculation time of the equipment, reducing hardware overhead, and to a certain extent reducing the system operating cost.

The invention discloses a sparse array design method based on co-prime array redundancy analysis, and relates to the field of DOA estimation. Comprising the steps of 1, establishing a signal model of a co-prime array; 2, redundant virtual array element analysis is carried out on the co-prime array; step 3, based on an analysis result of the step 2, forming two shift co-prime arrays, namely a CATrS-I array structure and a CATrS-II array structure, by moving the sub-arrays; and step 4, carrying out DOA (Direction of Arrival) estimation by adopting a CATrS-I array structure or a CATrS-II array structure. According to the invention, two sub-array shift co-prime arrays CATrS-I and CATrS-II are provided, the degree of freedom and the continuous degree of freedom can be effectively increased under the condition that the total number of physical array elements is kept unchanged, and mutual coupling of the array elements is inhibited.

The application discloses a kind of optimal arrangement method of non-uniform linear array for direction finding, comprising: based on preset array optimal arrangement model, the position, speed and initial local optimal position of initial quantum particle are generated;Based on preset array optimal arrangement model, the first fitness function based on minimum interval criterion and minimum maximum relative sidelobe level is constructed;Based on the first fitness function, the initial global optimal position of quantum particle is obtained;Based on initial local optimal position and initial global optimal position, the speed and position of quantum particle are updated, and the global optimal position is obtained;Based on global optimal position, the optimal array arrangement result is obtained.The application designs an optimal special array arrangement method based on minimum interval criterion and minimum maximum relative sidelobe level, finds optimal array arrangement mode using discrete quantum particle swarm, and realizes high-precision direction finding of optimal array arrangement under specific conditions and requirements.

The application discloses a kind of satellite transceiver's dual antenna radio frequency channel isolation circuit, comprising: circuit board, main input port, slave input port and signal processing chip;The input circuit of main input port is divided into two ways on the front of circuit board;First road passes to the back of circuit board and is divided into first subcircuit and second subcircuit;First subcircuit is connected to the back B3M frequency conversion processing circuit by first intermediate layer;Second subcircuit is connected with B1M frequency conversion processing circuit;Second input circuit passes to the back and is connected with auxiliary frequency conversion circuit;The input circuit of slave input port passes to the back and is divided into third input circuit and fourth input circuit;Third input circuit passes to the front and is connected with B3S frequency conversion processing circuit;Fourth input circuit is connected to the front B1S frequency conversion processing circuit by second intermediate layer.The present application carries out frequency conversion processing to slave input signal and main input signal respectively on the front and back of circuit board, reduces the direct coupling and radiation interference between signals.

The present invention provides a distributed array layout structure optimization method, system and storage medium based on a discrete quantum electromagnetic field optimization mechanism, which relates to the technical field of array signal processing, and aims to solve the problem that the existing methods mostly use the maximum sidelobe level as the optimization target, and the performance of the distributed array is seriously attenuated under harsh conditions such as small sampling snapshots and impact noise. The method includes the following processes: setting auxiliary source information and noise information in space to simulate and test the distributed array, and taking the source azimuth mean square error as the optimization target equation; initializing the quantum electromagnetic particle information in the quantum electromagnetic field to obtain the local and global optimal measurement positions; respectively using an evolution strategy based on quantum coding and an evolution strategy based on quantum rotation gate to update the quantum rotation angle and quantum position of each electromagnetic particle and obtain the measurement position; updating the local and global optimal measurement positions of the particles; and converting the final global optimal solution into the required array layout structure information.

The invention relates to an interferometer antenna position precision optimization method, which comprises the following steps of: S1, after the state of an antenna is checked, installing the antenna in place; s2, performing position precision optimization on the antenna according to two states of a floor and an extension rod mechanism through different methods; s3, binding antenna coordinate positions; and S4, completing on-orbit calibration, further reducing the influence of the antenna installation error on the positioning precision, and completing the optimization of the positioning precision. According to the invention, the influence of the antenna installation error is reduced, the direction finding accuracy of the satellite load direction finding system is improved, and the positioning precision of the satellite is greatly improved from the perspective of satellite application and satellite efficiency.

The invention discloses a direction finding method and device based on subarray-level digital multiple beams, and the method comprises the steps: converting an intermediate frequency signal of each subarray into a digital signal through a digital collection channel of the subarray; setting beam positions according to wide angle intervals to generate a multi-beam weighting coefficient table, and performing simultaneous complex weighted summation processing on all digital channelized signals of the sub-arrays to generate original beam signal data of the sub-arrays; adjacent beams are added and multiplied by a beam adjustment coefficient to generate derivative beam data. A two-dimensional multi-beam amplitude-comparison direction-finding method is adopted to calculate an actual target signal azimuth angle and a pitching angle; and summarizing all digital channelization processing results of the azimuth angle and the pitch angle of the actual target signal, and integrating with a pulse description word result of the reconnaissance and direction finding system to form a reconnaissance and direction finding result of each digital channel. The method has the advantages that the direction finding precision and the instantaneous airspace coverage rate index of the reconnaissance and direction finding system can be greatly improved under the condition that the hardware architecture of the current reconnaissance and direction finding system is not changed.

The present invention discloses a method and system for digital multi-beam direction finding of unmanned aerial vehicles, which belongs to the field of electronic countermeasure technology. The method determines the real-time evaluation environment measurement signal-to-noise ratio by acquiring the relative distance between the unmanned aerial vehicle and the target radar; determines the beam mode of the target radar according to the magnitude of the real-time evaluation environment measurement signal-to-noise ratio and the preset minimum environment signal-to-noise ratio; when the real-time evaluation environment measurement signal-to-noise ratio is greater than the preset minimum environment signal-to-noise ratio, the beam mode of the target radar is a sparse beam mode; when the real-time evaluation environment measurement signal-to-noise ratio is less than the preset minimum environment signal-to-noise ratio, the beam mode of the target radar is a conventional beam mode; according to the beam mode selected by the target radar, digital multi-beam direction finding is performed by determining the amplitude difference between different beams of the target radar to obtain the target radar direction finding angle. The method can optimize energy consumption while maintaining high direction finding accuracy and spectrum coverage.

The present application belongs to the field of radio direction finding, and particularly relates to a weak signal high resolution direction finding method of random passive matched filtering. According to the direction finding device and the related parameters of random matched filtering, the array receiving signal of the direction finding device and the reference signal of passive matched filtering are determined; then the random matched filtering sample extraction matrix is determined, and the reference signal of random matched filtering is determined from the reference signal of passive matched filtering according to the random matched filtering sample extraction matrix; then the snapshot signal outputted by random matched filtering and its autocorrelation matrix are determined from the reference signal of random matched filtering and the array receiving signal of the direction finding device; finally, the high resolution spatial spectrum is determined from the autocorrelation matrix, and the direction finding result of random passive matched filtering is determined from the spectral peak position of the high resolution spatial spectrum. The present application can realize the purpose of improving the resolution capability and direction finding precision of signals with similar directions of arrival under the condition of low signal to noise ratio.

The invention discloses an OBA optimization method and system based on reinforcement learning and a storage medium, and belongs to the technical field of communication. The method comprises the following steps: an OBA table construction stage; a reinforcement learning reward mechanism setting stage: setting a reinforcement learning reward mechanism based on the monotonicity and directivity of the OBA table; in the initialization stage, the network weight, the experience playback buffer area and the initial state of the reinforcement learning algorithm are initialized; in the reinforcement learning network parameter updating stage, a reinforcement learning algorithm is operated according to the OBA table, batch data are randomly taken from the experience playback buffer area, the parameters of the reinforcement learning network are updated by using a gradient descent method, and the monotonicity and directivity of the OBA table are improved; and an intelligent agent and beam forming weight output stage: when the monotonicity and directivity of the OBA table reach preset index requirements, the intelligent agent and beam forming weight is output. Through an actual external field test, the quantitative proportion of the OBA table meeting the direction finding requirement can be improved by more than 15%, and the direction finding precision of certain communication equipment can be greatly improved.

The present invention discloses a method for extracting direction-finding correction parameters for a multi-antenna base station, wherein the extracted parameters include: phase difference zero bias parameters of each pair of antennas, which are used to correct the influence of fixed delay phase difference caused by non-signal transmission of a pair of antennas on direction-finding; and internal angle parameters of a unit group of three antennas, which are used to correct the influence of the geometric layout structure of a group of antennas on direction-finding. The obtained direction-finding correction parameters are written into the base station firmware as system fixed parameters, which can reduce the influence of several major error sources during real-time direction-finding and effectively improve the direction-finding accuracy; in addition, the process of this method is basically fully automatic, without manual intervention in the middle, simple and easy to use, and has a self-checking function for evaluating parameter availability, and the extracted direction-finding correction parameters are highly reliable.

The application provides a high-precision direction finding method and system based on amplitude-phase joint feature fusion, comprising: collecting radio signals and preprocessing; calculating the amplitude difference DA and the phase difference of adjacent elements, and constructing a joint feature vector; dynamically weighting and fusing the amplitude and phase features based on the real-time signal-to-noise ratio to obtain a fused direction feature; calculating the spatial spectrum function by using the spatial spectrum estimation technology, and determining the incoming direction angle by searching for the peak value; and finally, performing dynamic smoothing filtering on the continuous measurement results to output a stable direction angle estimate. Through the deep fusion and intelligent weighting of the amplitude and phase features, the direction finding precision and robustness in complex environments such as low signal-to-noise ratio and multipath interference are significantly improved, and the application is suitable for fields such as spectrum monitoring, radio positioning and electronic reconnaissance.

The present disclosure relates to the field of radio monitoring, and in particular to a signal direction finding method, system, storage medium and electronic device. The method includes: based on an N-element directional antenna array, collecting radio signals in space to obtain a composite radio signal, wherein N is greater than or equal to 2; based on a single-channel receiver, receiving the composite radio signal, and performing signal conversion on the composite radio signal to obtain a baseband signal corresponding to the composite radio signal; based on the baseband signal, calculating the array signal parameters of the N-element directional antenna array, the array signal parameters include the array element amplitude of each array element in the N-element directional antenna array and the phase difference between two array elements; according to the array signal parameters, determining the incoming wave direction of the radio signal in space. By combining the N-element directional antenna array with a single-channel receiver, the sensitivity is improved, the mutual coupling effect is reduced, the system architecture is simplified and the cost is reduced, providing a new solution for signal direction finding.

The application relates to a direction-finding method based on array-received data reconstruction, and belongs to the technical field of array signal processing. The application first calculates the covariance matrix of array-received signals, then combines the array flow characteristics to use the elements in the covariance matrix to perform array-received data reconstruction, and finally performs direction finding based on the reconstructed received data matrix, so that the processing gain and the direction-finding precision are further improved. The application can improve the processing gain of array signals and the spatial resolution of array direction finding without increasing the number of array elements and the array aperture. Compared with the traditional beam synthesis method, the application has higher direction-finding precision and sidelobe suppression ratio.

The invention belongs to the technical field of interferometer signal processing, and particularly relates to a small interferometer system phase calibration method and device, and the method comprises the steps: S1, obtaining the signal frequency of a measured incoming wave signal, and searching a phase difference calibration table of different angle intervals of a calibration frequency point corresponding to the signal frequency; s2, calculating a phase difference data vector relative to a reference measurement phase by using the phase of the incoming wave signal measured by each receiving channel; s3, traversing the phase difference calibration table, and determining a standard phase difference data vector closest to the phase difference data vector in the phase difference calibration table; s4, estimating an azimuth angle interval and a pitch angle interval of the incoming wave signal; and S5, based on the longest baseline distance, determining an accurate angle in the azimuth angle interval and the pitch angle interval. According to the invention, the ambiguity resolution correctness of the interferometer direction-finding system is ensured, and the direction-finding precision of the interferometer direction-finding system is effectively improved.

The application discloses a full-space coverage array wave direction estimation method and equipment, the method comprises the following steps: using a single polarization dipole antenna or a double cone antenna to form a three-layer uniform cylindrical array; using a darkroom to collect measured data to construct a calibration data set; obtaining a to-be-measured vector of an unknown signal; operating the to-be-measured vector and the calibration data set to form a spatial spectrum; finding the position of the strongest energy point in the spatial spectrum to obtain wave direction estimation; finding the double polarization calibration data of the strongest energy direction in the calibration data set; and obtaining polarization information estimation through the corresponding double polarization calibration data and the to-be-measured vector. The application can effectively solve the technical problems of insufficient full-space coverage and slow direction finding speed, improve the full-space coverage and timeliness of radar signal direction finding in a complex electromagnetic environment, and has the advantages of less required antennas, low cost and low operation complexity.

The present invention proposes a method for forming multi-beams with adaptive beam widths of tilted arrays, which uses azimuth multi-beam pitch scanning to traverse and search the spatial coverage range, and makes matching compensation for the pitch pointing angle according to the vertical beam width of the pitch pointing direction of the lateral multi-beam; the horizontal beam width of each beam in the horizontal direction of the same pitch layer is kept the same as the horizontal beam width of the azimuth method beam of the layer through the Taylor window coefficient widening method. The present invention makes full use of the spatial resources of the phased array to receive multiple beams at different pitch angles, and only performs beam widening in the horizontal dimension. Under the premise of meeting the spatial coverage requirements of the geodetic coordinate system, the directional pattern distortion of the side beam is reduced as much as possible, thereby improving the direction finding accuracy of the array.