94 results about "Ground based radar" patented technology

The present invention is a Sense-and-Avoid Display System (SAVDS) that integrates data from a ground-based short-range tracking radar with positional data from a global positioning system (GPS) element in the flight management autopilot system in the unmanned aerial vehicle. Using a high-resolution display, the SAVDS shows the GPS location of the unmanned aerial vehicle in relation to other aircraft operating in the same airspace. With the SAVDS co-located on the same tabletop as the computer controlling the unmanned aerial vehicle, the SAVDS operator can instruct the unmanned aerial vehicle pilot to change the heading of the vehicle until any potential aircraft conflict is abated. Ground-based radar data and GPS data are integrated and displayed with georeferenced base maps that provide collision avoidance information, and provide a means for tracking the UAV relative to geographic waypoints.

A technique is provided that uses a dual mode seeker (IR and LADAR) for precise target dynamics measurement, which extends stripping to a much higher altitude than ground based radar. Initial results show that this approach works to altitudes in excess of 100 km. Stripping becomes a reliable way to discriminate lighter weight decoys from reentry vehicles at altitudes and ranges consistent with planned divert capabilities for terminal phase missile defense. It is a finding of this invention that the LADAR will improve the spatial resolution by a factor of five over typical missile defense IR seekers using a common aperture. The LADAR provides a 3D angle, angle, range (AAR) image for each laser pulse which is used to extract the precise target state vectors.

The invention discloses a remote air-to-air missile multi-platform cooperative guidance system and a realization method thereof. The multi-platform cooperative guidance system comprises an early warning plane module, a ground base radar detecting module, an aerial carrier module, a friend plane module, a remote air-to-air missile module, a target information space-time normalizing module and a target information fusion module. The realization method comprises the following steps: 1. an early warning plane, a ground base radar guided aerial carrier and a friend plane fly to a war area; 2. the radar of the friend plane operates to detect a target, and the aerial carrier launches an air-to-air missile; and 3. the targets detected by the radar of the early warning plane, the ground base radar and the radar of the friend plane are fused, and the friend plane carries out midcourse guide on the air-to-air missile. By adopting a multi-platform combat network formed by the early warning plane, the ground base radar, the aerial carrier and the friend plane to provide high-accuracy target information for the remote air-to-air missile, and adopting the friend plane to perform midcourse guide on the remote air-to-air missile, a remote target can be attacked stealthily and accurately.

The present invention concerns an apparatus for collecting ground radar data with polarization information comprising a main body exhibiting structure for moving the apparatus along the ground, a part that rotates in relation to the main body supporting a pair of antennas of transmitter and receiver type, a power source with connected control unit for controlling and governing the ground radar, a transmitter unit electrically connected to one of the pair of antennas for generating and transmitting radar pulses and a sampler unit electrically connected to the other antenna for receiving the reflected radar pulses. To improve signal quality and reduce sensitivity to interference, the rotating pair of antennas support the transmitter unit, sampler unit and A / D converter contained in the sampler unit, the power source and the control unit are located in the main body and are electrically connected to the transmitter unit and sampler unit via a slip-ring arrangement, in which the radar signals are conveyed digitally via the slip ring arrangement.

The invention provides an antenna array forming technology-based ground-based radar system for space debris, which comprises a signal emitting part, a signal receiving part and a frequency and time unified signal board, wherein the signal emitting part comprises a signal generating source, a digital beam former, a phase synchronous circuit, a plurality of up-converters, a plurality of power amplifiers and an emitting antenna array; the emitting antenna array is a one-dimensional antenna array consisting of a plurality of emitting antennas along the east and west direction; each emitting antenna is used for emitting a signal amplified by a corresponding power amplifier to the space debris; the signal receiving part comprises a receiving antenna array, a plurality of low noise amplifiers, a plurality of down-converters, a plurality of analog-to-digital converters, a space debris accurate measurement module, a space debris common measurement module and a data postprocessing interaction module; and the receiving antenna array is a two-dimensional antenna array consisting of a plurality of receiving antennas arranged according to a plane, and is used for receiving signals reflected by the space debris.

A system and method of providing to a beamformer a modified complex beam steering vector includes collecting subarray I / Q samples from a plurality of subarrays receiving clutter, performing coherent integration of the subarray I / Q samples to increase the CNR, adaptively modifying a complex beam steering vector to form a null in the direction of the received clutter, and outputting to a beamformer the modified complex beam steering vector. The beamformer receives complex I / Q data samples representing a radar signal containing near-horizon clutter and applies the modified beam steering vector to generate a beamformed signal having an elevated mainlobe and a spatial sidelobe null in the direction of the received clutter.

The invention provides a calibration method and calibration system for the amplitude phase error of a satellite-borne DBF (Digit Beam Forming) transmitting channel. The calibration method and the calibration system respectively comprise two levels of calibration schemes, and the two levels of calibration schemes are composed of output Butler front-end channel part amplitude phase calibration and output Butler rear-end channel part amplitude phase calibration. The method comprises the following steps of: firstly, injecting a calibration signal after inputting the Butler, and coupling the calibration signal at a test port which transmits the Butler, thereby realizing the calibration of a frequency mixer and a power amplifier; and then, keeping the original calibration signal injection mode, and receiving the calibration signal through a far field, thereby realizing the calibration of a filter and a feed source array. Through the method and system provided by the invention, the measurement accuracy of the amplitude phase error is improved greatly, so that the method and the system can be used for effective loads of communication satellites, detection satellites and navigation satellites, and also can be used in the technical fields of ground radars and the like.

The present invention discloses a spaceborne radar and ground-based radar reflectivity factor data three dimensional fusion method. According to the present invention, by using the precipitation radar (PR) data of high vertical resolution as the output of a neural network and the ground radar (GR) data of high horizontal resolution and low vertical resolution as the input, a non-linear relationship of a PR and a GR is established, thereby fusing into the three dimensional reflectivity factor data having the high vertical and horizontal resolution. Based on a neural network algorithm, the PR and GR reflectivity factor data three dimensional fusion is carried out to obtain a fine three dimensional structure of an intensity echo which is very important for the later applications, such as the fine detection and tracking of a middle and small-scale convective weather process, the subsequent quantitative rainfall measurement, the radar data assimilation in the middle-scale forecast, etc.

The present invention relates to a method for correcting environmental influences at slope deformation monitoring on the basis of a corner reflector belonging to the technical field of ground-based radar monitoring. The method includes the steps as follows: performing calibrating, focusing, interfering and difference handling for radar monitoring data of the corner reflector and a target point so as to acquire displacement values of the corner reflector and the target point; acquiring a Voronoi diagram according to a Thiessen polygon rule; acquiring a geometric position relationship of the target point and the corner reflector point closest the target point; subtracting the acquired displacement of the corner reflector closest the target point according to the acquired displacement of the target point; performing environmental influence correction for the target point by utilizing single corner reflector so as to acquire the effective displacement of the target point; performing weight configuration according to the geometric position relationship of the corner reflector point and the target point when a great error exists after the correction of the single corner reflector; and performing environmental influence correction by utilizing a manner of weighted average of the corner reflectors. The method can efficiently correct environmental influences by combining the ground-based radar interferometry principle with the Thiessen polygon rule.

The invention discloses an atmospheric phase screen extraction method based on ground-based SAR (synthetic aperture radar) interference. Atmospheric phase is extracted according to a ground-based radar differential interferometric phase model on basis of a least squares fitting linear deformation and time-space filtering method. The ground-based radar differential interferometric phase model has a full consideration of the ground-based radar imaging mechanism and the differential interference theory so as to extract an atmospheric phase screen. A PS (permanent scatterer) point selection method of three levels, amplitude dispersion index, correlation index and phase stability, is provided, the atmospheric phase screen of radar data of each scene is finally obtained by means of Kriging interpolation, and accurate extraction of the phase generated under atmospheric interference has an important role on improving radar interferometric precision. Correctness of the method is verified by measured dam data, and the method is of certain actual application value and universality.

The invention discloses a ground-based radar multi-target detection method based on compressed sensing. The method includes the steps that sparse representations of echo signals are completed, and a sparse transform matrix is schemed out; a random Gauss matrix is chosen as an observation matrix, and each row vector in the observation matrix is used for projecting target echo signals; part of signal information is obtained, and the echo signals undergo reduced-order observation; the sparse representations of the target echo signals are set as optimization variables, and a convex optimization model is established and solved to obtain a global optimum solution of the sparse representation signals; according to the sparse matrix construction method and the sparse representations of the echo signals, a target time-lag and a target Doppler frequency are obtained. Compared with a traditional orthogonal matching method, the method can correctly detect a large number of targets when the number of targets is uncertain.

The invention discloses a high-speed maneuvering target detection method based on discrete linear frequency modulation Fourier transform. The method comprises the steps that 1 a radar echo is received, and demodulation and pulse pressure processing are carried out on the radar echo; 2 in the fast time domain, Fast Fourier transform and Keystone transform are carried out on the echo signal in order; 3 the search range, interval and number of the speed fuzzy number, the linear frequency modulation slope and the secondary frequency modulation slope are initialized, and a fuzzy speed compensation function is built; 4 Keystone transformed data are multiplied by the fuzzy speed compensation function, and then fast inverse Fourier transform is carried out in the fast time domain; 5 improved discrete linear frequency modulation Fourier transform is carried out on the data processed in the step 4; and 6 the steps of 4 and 5 are repeated until the search of the speed fuzzy number is completed, and a detection unit diagram is constructed for constant false-alarm detection. The method provided by the invention has the advantages of better detection performance and smaller calculation amount, and can be used for remote early warning of a ground-based radar.

The invention discloses a multi-target arrival time difference positioning method based on height-dimension segmented searching. On the basis of the geometric characteristic of being far less than a distance between a target and a ground-based radar observation station by a height dimension difference between the target and the ground-based radar observation station, segmented searching is carried out by using the height dimension of the target as known one within an effective height range; positioning is carried out by using observation station detection values in paired traverse combination and two-dimensional plane coordinate values of all possible targets are calculated; and detection data having same coordinate values are classified into one target set and target association is carried out. Because the probability of occurrence of real target signal data in detection values of all radar receiving observation stations is larger than a false alarm value, when one detection value occurs in several possible target sets, only the target set with the most set elements is kept and thus possible false target association is rejected. The method is applied to an arrival time difference positioning system to improve the positioning performance of a time difference of arrival (TDOA) on the multi-target condition.

The invention discloses a rail traffic safety detection method and relates to the technical field of rail traffic safety and measurement and control. Ground radars are deployed in a predetermined monitoring area along a rail; a coordinate system is set, a rail equation is established, and the positions of the radars are marked; radar wave beams (such as laser beams) parallelly scan rail passing surfaces; when prominent suspected obstacles are detected, the direction and distance are obtained, calculation and comparison are conducted in reference to the rail equation, and when it is judged thatthe prominent suspected obstacles are within the rail passing belt range, alarming is conducted; inter-radar scanning cross coverage is conducted to establish synergistic vigilance; according to alarming, illumination is provided, and scene videos are shot; and alarming is further screened, and the normal passing parking time period and the repairing maintenance time period are excluded. A rail is subjected to scanning detection in all-line, all-day, all-weather, full-automation, unattended operation, high-efficiency and high-precision modes, the dangerous obstacles can be accurately distinguished, natural and man-made disasters are found and recorded in time, credible monitoring and pre-warning are provided for rail traffic travelling safety and property protection to guarantee emergencyresponse, the rail traffic safety is improved, the safety of taking travel and freight transport is strengthened, and social and economic benefit value is high.

The invention discloses a digital television signal mobile platform passive radar system and a digital television signal mobile platform passive radar signal processing method. The system comprises a receiving antenna array, a multi-channel analog front end, a signal collecting device, a signal processing device, a signal storing device and a mobile platform. The multi-channel analog front end is composed of signal analog receiving assemblies. The signal collecting device is composed of signal collecting assemblies, the signal processing device is composed of signal processing assemblies, and the signal storing device is composed of signal storing assemblies. The method includes the steps that firstly, direct wave signals are purified to obtain reference signals; then, amplitude phase correction is performed on the receiving antenna array; then, pre-filtering processing is performed in a time domain to filter out direct waves and short-distance ground clutters or sea clutters; filtering processing is performed in an empty time domain to filter out remaining empty time domain coupled ground clutters or sea clutters; finally, clutter characteristic analysis and distance Doppler two-dimensional calculation are performed to finish target detection. Low-level blind areas existing in ground-based radar can be eliminated, rapid maneuver deployment can be achieved, the clutters are restrained better, and target detection performance is improved.

The invention discloses a dam body three-dimensional deformation monitoring-oriented combined observation method with two ground-based radars. The method comprises the following steps of S1, generating a three-dimensional model; S2, constructing a ground-based radar system; s3, obtaining radar data; s4, fusing the radar data and the three-dimensional model to obtain a fused model; and S5, monitoring the measured target based on the fused model. A three-dimensional model of a key target in a monitoring area is constructed by using a point cloud data set of the monitoring area acquired by a ground three-dimensional laser scanner and an unmanned aerial vehicle oblique photogrammetry technology. Different from an existing calculation result in abstract expression forms of numbers, characters, images and the like, after the three-dimensional model is constructed and used, a result calculated according to data acquired by the ground-based radar can be displayed in front of a user in a more intuitive manner, the professional threshold of interpreting the calculation result is reduced, so that the method can be accepted and applied by vast demanders more easily, and the practicability is higher.

The invention relates to a meteorologic correction model in slope deformation monitoring, wherein the meteorologic correction model belongs to the technical field of ground radar monitoring. Firstly according to a temperature, a relative humidity and an air pressure which are monitored in real time, a refractive index change value is calculate through an Essen Froome empirical formula which is recommended by International Union of Geodesy and Geophysics. Scaling, focusing, interference and difference processing are performed on radar monitoring data. An additional displacement of an angle reflector caused by a meteorologic effect is obtained according to the geometric position, an estimated signal-to-noise ratio, a thermal signal-to-noise ratio and correlation information of the angle reflector. According to the calculated refractive index change value, the azimuth coordinate value and the range coordinate value of the angle reflector, the meteorologic correction model of the ground radar in slope deformation monitoring is established by means of a nonlinear fitting method, so that a difference between the calculated value of the model and the additional displacement which is caused by an environment effect is minimized. The meteorologic correction model can effectively correct the meteorologic effect.

The invention discloses a method for determining an initial orbit of spacecraft based on a precise orbit model. On the basis of the precise orbit model and a laplace equation, a weighted least squaresconditional equation of ground-based radar orbit measurement data, space-based optical angle measurement data, GNSS and Beidou orbit measurement data is established, and improved values of initial positions and velocity are iteratively solved by integrating different kinds of orbit measurement data by using two methods of a direct synthesis method or a federated synthesis method. According to themethod for determining the initial orbit of spacecraft based on the precise orbit model, the complete or incomplete external ballistic observation data, the position and velocity component observation data and the space-based angle measurement data can be directly combined to carry out the satellite-rocket separation initial orbit calculation, and the unique initial orbit output is produced.

The invention relates to a light detection and ranging (LiDAR) point cloud filtering method, in particular to a progressive triangulated irregular network point cloud filtering method based on voxel, which is applicable to airborne and ground-based radar point cloud data processing and belongs to the technical field of LiDAR point cloud data processing. The method comprises the following steps: loading LiDAR point cloud data; preprocessing the LiDAR point cloud data, and organizing and managing the point cloud data in a segmented way; determining a mathematical expression of LiDAR point cloud voxelization, and voxelizing point cloud; determining LiDAR point cloud multi-echo information, and retaining single echo and the last echo point in multiple echo; determining a mathematical expression of a LiDAR point cloud progressive triangulated irregular network, and filtering point cloud; and determining LiDAR point cloud multi-echo information, and retaining single echo and the last echo point in multiple echo. The method of the invention is applicable to complex terrain surfaces, is sensitive to detection of dense vegetation areas, steep slopes and irregular fracture zones, and can be used to generate a high-precision digital elevation model (DEM).

The invention discloses a time-frequency domain combined ground radar automatic target recognition method and system. The recognition method comprises the steps: carrying out the time-domain feature extraction of I and Q paths of echo signals, carrying out the Fourier transform of a baseband echo signal after the down-conversion processing of a radar echo signal, and extracting the frequency-domain features; and sending the extracted time domain features and the frequency domain features to a classifier, and performing judgment according to output values. The system comprises a feature calculation module used for calculating and obtaining feature information of a target; and a judgment identification module which is used for sending the extracted features into the designed classifier and determining target attributes according to an output judgment result. The method is easy to implement, high in judgment efficiency and high in ground radar target attribute recognition accuracy of thelow-resolution radar.

The invention belongs to the field of radar signal processing, and relates to a method for forming a two-dimensional profile clutter map of a fixed platform radar for earth observation. The steps of forming a two-dimensional contour clutter map are as follows: range-wise pulse compression processing; double-pole filtering; performing range-dimensional clutter detection to form a range-azimuth two-dimensional matrix; forming a range-azimuth two-dimensional matrix for multiple scan cycles; Range-azimuth two-dimensional mean matrix; forms two-dimensional contour clutter map. The present invention proposes a method for forming a two-dimensional contour clutter map of a fixed platform radar for earth observation, using the formed two-dimensional contour clutter map to suppress the clutter of fixed buildings and other fixed reflectors on the ground, reducing the Target false alarm probability.

The present invention is a ground-based radar two-dimensional sparse array detection system and method for space debris, which combines the advantages of mechanical tracking radar, phased array radar and electronic fence, and at the same time makes up for their respective shortcomings to a certain extent. On the basis of maintaining high-precision positioning and multi-target acquisition capabilities, the transmission uses a single-axis scanning torus antenna, which is a flat beam antenna and has a certain airspace coverage; the reception uses a two-dimensional sparse antenna array. Based on the one-dimensional debris search fence, the receiving range of the antenna is increased, and the positioning accuracy of debris is improved. In the present invention, the system used is scientific and reasonable in construction, low in construction cost, capable of cold start, and capable of discovering new fragments; the launch station is movable, flexible, convenient in disassembly and assembly, and has good emergency response capabilities. The invention can better meet the increasingly urgent space debris detection task requirements of our country, and has strong practicability, application value and important practical significance.

The present invention relates to a time-division multiplexing technology-based networked ground-based radar semi-physical system. The system includes an X-band command and control radar semi-physical verification system, a Cobra Dane radar semi-physical verification system and an early warning radar semi-physical verification system; the three verification systems work jointly so as to simulate required battlefield environments more completely, and therefore, fidelity is high, implementation possibility is higher; and a time-division technology, semi-physical model and functional auxiliary verification module-combined method is adopted, and therefore, the costs of actually-created semi-physical equipment are decreased, a test method is simplified, and test difficulty is reduced.

The invention discloses a ground radar automatic target classification and recognition method based on a one-dimensional convolutional neural network. The method comprises the following steps: preprocessing radar human and vehicle echo target sample data; obtaining a time domain echo signal, a power spectrum and a power conversion power spectrum, processing the preprocessed feature vector by usingan auto-encoder, constructing a one-dimensional convolutional neural network (1D-CNN) structure, and optimizing hyper-parameters of the convolutional neural network structure by using a Bayesian hyper-parameter optimization method. And inputting the coded data into a one-dimensional convolutional neural network, and performing target classification and recognition through a softmax classifier toobtain a classification and recognition result of personnel and vehicle samples. According to the method, the target classification and recognition function can be efficiently and stably completed, the calculation speed is high, implementation is easy, the network structure is simplified, the parameter calculation scale is reduced, and the method has excellent recognition accuracy for target classification and recognition of the low-resolution ground radar.

The invention discloses a ground-based radar adaptive range-amplitude weighting system and method. The method includes the steps that, firstly, a high-speed ADC module receives medium-frequency echo signal of radar and performs digital processing to the signal to acquire medium-frequency digital echo signal; secondly, an FPGA module performs digital orthogonal down-conversion processing to the medium-frequency digital echo signal, acquires baseband data and stores the same in an EMIF(expansion memory interface) of a DSP (digital signal processor); thirdly, the DSP module acquires the basebanddata stored at the last step, gains a weighting coefficient according to the baseband data, stores the weighting coefficient to the EMIF thereof; finally, the FPGA module reads the weighing coefficient from the EMIF of the DSP, and performs digital orthogonal down-conversion processing to the medium-frequency digital echo signal according to the weighting coefficient to acquire weighted baseband data, thereby achieving adaptive range-amplitude weighting. The system and method can guarantee fixed-point processing of echo in a heavy-clutter area without overflow, improve clutter base of remote light-clutter area, and further improve radar detection and false-alarm performance.

An efficient conduction material structurally at least comprises a layer of metal fiber non-woven felt layer capable of conducting electricity, heat and electromagnetism with high speed, wherein the preference is an aluminum fiber non-woven felt. A base is various kinds plastics, and the preference is glass fiber reinforce plastics. The metal fiber non-woven felt can be compatible with common resin, cannot be influenced by electromagnetic signals easily, is added in the same process of plastics manufacturing with glass fibers, does not need to increase a novel process, is simple in process, dose not increase production cost. The efficient conduction material can be used as antennas of satellites and ground-based radars, directional antennas of broadcast communication, cables, electromagnetic interference shielding elements of aviation and automobiles, wave-absorbing materials of specific radars and the like.

The invention provides a novel method for inverting bridge bearing capacity by a ground-based radar. The method comprises the following steps: scanning a bridge by utilizing the ground-based radar, combining continuous waves with frequency modulation and an interferometry technology to detect strain conditions of the bridge at any moment and at any position, and obtaining a displacement time sequence chart, a displacement time series spectrogram, an amplitude spectrogram, a time-domain deflection form chart, a frequency-domain deflection form chart of bridge monitoring sites; and providing a theoretical basis for bridge bearing safety according to the actual bridge bearing capacity during a static load test of ground-based radar data inversion and the autodynamic performance and dynamic response data of the bridge structure during a dynamic load test. According to the method disclosed by the invention, other instruments do not need to be installed on the bridge, namely bearing capacityinformation (comprising natural vibration frequency, deflection and the like) at any scanning position of the bridge and under different working conditions can be acquired at precision of 0.01mm, andnon-contact measurement is performed. According to the method disclosed by the invention, static bridge measuring and dynamic monitoring can be realized, the vibration frequency reaching 4000Hz of the bridge can be monitored, and data distortion brought by data conversion among multiple instruments during the traditional monitoring is avoided.

The invention relates to the field of detecting a moving target by a narrow-band ground-based radar in a clutter environment, and particularly relates to a method for detecting a low signal-to-clutterratio (SCR) moving target by a stepped frequency coherent processing. The method comprises the following steps: transmitting an inter-pulse same frequency signal by a radar with the frequency stepping between pulse group signals, firstly performing equal order AMTI on each carrier frequency pulse group signal in a group in the received signal processing; performing step frequency phase synthesisafter phase compensation on a time-aligned AMTI result of each carrier frequency; and finally completing coherent accumulation by a step frequency synthesized image at a slow beat; thereby completingseparation between the moving target and the remaining clutter, and achieving a purpose of improving the SCNR of the moving target detected.