32 results about "Bistatic radar" patented technology

This disclosure provides systems, devices, apparatus, and methods, including computer programs encoded on storage media, for bistatic radar assistance sensing. A radar-receiver receives (210), from a radar-transmitter, a configuration message that configures the radar-receiver to assist the radar-transmitter with bistatic radar sensing. The radar-receiver receives (214) a reflection of the radar signal. Responsive to the receiving the reflection of the radar signal, the radar-receiver transmits (218), to the radar-transmitter, a radar measurement report message. The radar-receiver receives (202), from the radar-transmitter, a radar capability enquiry. The radar-eceiver transmits (204), to the radar-transmitter in response to the radar capability enquiry, a radar capability response that indicates radar capabilities supported by the radar-receiver for the bistatic radar sensing.

The present application belongs to the technical field of radar imaging, and relates to a kind of dual-base radar cooperative imaging method based on complementary random waveform, it is characterized in that, including the following steps: step 1: establish dual radar cooperative detection echo model, radar 1 and radar 2 all adopt random frequency hopping waveform;Step 2: carry out distance difference compensation, eliminate the phase modulation term of the phase difference of the echo signal received by radar 1 and radar 2, realize distance difference compensation;Step 3: carry out echo motion compensation, eliminate the component related to velocity component in echo, realize echo motion compensation;Step 4: carry out band fusion imaging, rearrange different frequency band random frequency hopping, carry out zero filling processing to echo data on the missing frequency point, and through setting tight constraint condition, make the echo signal of two radar through FFT transformation to realize phase correlation fusion imaging.The imaging method of the present application designs new frequency hopping waveform, realizes efficient motion compensation, and realizes band fusion by using phase correlation processing algorithm.

The invention discloses an airborne bistatic radar platform error compensation and target positioning method and system. The method comprises the following steps: constructing a measurement model for a bistatic radar system; the measurement model comprises a platform position motion model, a target position motion model, an observation equation of a platform to a target and a navigation error model of the platform; based on the measurement model, performing linear fitting on each platform position measurement and target position measurement by using a linear fitting model, estimating navigation error parameters of each platform according to fitting results, and correcting platform motion parameters according to estimated values of the navigation error parameters; and based on the corrected platform motion parameters, constructing a linearized target positioning model in combination with multi-platform observation data, and estimating the motion parameters of the target by using a weighted least square method to realize target positioning. Under the condition that no navigation source exists, the positioning precision of the airborne platform is improved, and then the positioning precision of the bistatic airborne radar on the non-cooperative target is improved.

The invention discloses a time sequence generation and phase calibration method for a cooperative external radiation source radar system, and belongs to the field of radar signal processing, and the method comprises the steps: receiving a direct wave signal from a transmitting station in the cooperative external radiation source radar system, and determining a direct wave pulse pressure peak value position of a current PRT; when the last PRT of the current CPI is not reached, the sampling starting time of the next PRT is determined by utilizing the direct wave pulse pressure peak value position so as to sample echo data, the echo data are returned and processed continuously until echo signals of the whole CPI are obtained, and a fast-slow time dimension two-dimensional matrix is reconstructed; performing pulse compression on each PRT along a fast time dimension to obtain a fast-slow time dimension two-dimensional matrix after pulse compression; a smoothed phase sequence is obtained by extracting the maximum peak phase of each PRT; and compensating the phase difference of each PRT by taking the first PRT as a reference so as to finish phase correction. According to the invention, system inconsistency caused by asynchronous clock sources between double bases can be corrected.

The invention discloses a radar track target classification method based on statistical knowledge and a neural network, and the method comprises the steps: collecting original track data, and carrying out the marking and cleaning processing, and obtaining a standard track data set; extracting kinematics, bistatic radar cross section and track morphological features based on the standard track data set, and constructing an original feature set; performing feature weight learning through a neighborhood component analysis method, and screening according to a preset weight threshold to obtain an effective feature subset; performing statistical distribution analysis on the effective feature subsets according to target categories, determining significant features of each target category, and setting a threshold interval; performing preliminary classification based on a statistical knowledge classifier, and determining whether the to-be-classified track is an easily-classified sample or a difficultly-classified sample through a category discrimination function; and classifying the samples difficult to classify based on a back propagation neural network classifier, outputting the probability value of each target category through a neural network model, and taking the target category with the maximum probability value as a final classification result. According to the invention, the target classification accuracy and real-time performance can be improved.

A method includes receiving a set of radar signals incident on a set of objects. The method includes selecting a GLRT detector. The method includes determining a ratio between a maximized likelihood function of a second hypothesis model and a maximized likelihood function of a first hypothesis model. The method includes determining whether a set of angles associated with the set of radar signals is available. The method includes, in response to a determination that the set of angles is available, updating a set of data associated with a set of objects. The method includes, in response to a determination that the set of angles is not available, selecting an angle estimation method, estimating the set of angles, and tracking the set of objects.

The invention belongs to the technical field of radars, and relates to a double-station radar clock synchronization method and system based on distance measurement and a storage medium. The method comprises the following steps: acquiring orbit information of a precise orbit satellite; the first radar station and the second radar station simultaneously emit linear frequency modulation ranging signals with positive frequency modulation slope and negative frequency modulation slope to the precise orbit satellite target at an agreed moment taking the clock of the first radar station as a reference; the first radar station and the second radar station measure a single-base one-way distance measurement result and a double-base distance measurement result according to the distance measurement echo signals; calculating an inter-station clock synchronization error according to a bistatic ranging result; according to the single-base one-way distance measurement result and the double-base distance measurement result, the inter-station hysteresis is judged; and correcting the clocks of the two stations according to the inter-station clock synchronization error and the inter-station hysteresis. According to the invention, high-precision clock synchronization is realized by using the rule that bistatic ranging errors are caused by clock synchronization errors between radar stations.

This invention discloses a method for estimating atmospheric errors in bistatic satellite-to-ground radar target detection using high- and low-frequency joint reception. The method first obtains a large-scale atmospheric delay estimate through multi-source data fusion and ray path integration to achieve coarse compensation; then, it extracts the residual atmospheric phase based on echo self-calibration to achieve fine compensation; finally, it combines high- and low-frequency constraints to achieve phase deambiguity and extract the absolute total atmospheric delay. From global modeling to local correction and cross-band consistency, it achieves accurate estimation of atmospheric delay errors along the propagation path.

The present invention describes an antenna device (33) for a radar device, particularly for a bistatic radar device, particularly for a vehicular radar device, a radar device, a driver assistance system, a vehicle, and a method for operating the radar device. The antenna device (33) has at least one type 1 antenna element (Tx) of a first antenna element type and at least one type 2 antenna element (Rx) of a second antenna element type. One of the antenna element types is a transmit antenna element (Tx), and the other antenna element type is a receive antenna element (Rx). The antenna device (33) has at least two antenna arrangements (30) of identical design. The position of at least one antenna element (Rx, Tx) of the antenna arrangement (30) within the antenna device (33) results from a geometric transformation of the position of at least one other corresponding antenna element (Rx, Tx) of the antenna arrangement (30). The geometric transformation comprises at least one rotation (88) of the positions of the antenna elements (Rx, Tx) of at least one second-mentioned antenna arrangement (30) around an assumed direction axis (86) by a predetermined rotation angle, the assumed direction axis (86) indicating the direction in which the antenna arrangement (30) is pointed.

The application provides a spaceborne bistatic SAR imaging system and method, comprising: a transmitting signal adopts a coded signal pulse sequence as a periodic transmitting sequence, and the relationship between any pulses is orthogonal; a pulse repetition frequency is set based on a bistatic configuration, and the adopted pulse repetition frequency should make the space-to-space direct wave and the bistatic SAR ground echo be received simultaneously, and the corresponding radar transmitting signal waveforms of the two are different; based on the setting of the coded signal pulse sequence and the setting of the pulse repetition frequency, the space-to-space direct wave and the bistatic SAR echo of an observation area which are mixed together in time are obtained, and the space-to-space direct wave and the bistatic radar echo signal obtained at the same time are orthogonal; based on the obtained space-to-space direct wave and the bistatic SAR echo of the observation area which are mixed together in time, the space-to-space direct wave and the bistatic SAR echo of the observation area are extracted respectively, and the function of spaceborne bistatic SAR imaging under space-to-space direct wave suppression is realized.

The application relates to the technical field of bistatic radar imaging, in particular to an external radiation source bistatic imaging system and method under a motion platform. The system comprises a motion platform provided with a GPS signal receiving module, a high-dynamic receiving platform posture measuring module, a high-dynamic receiving platform position error calculating module, a one-dimensional range image processing module, a range upsampling module, a grid dividing module and a reverse projection two-dimensional imaging module. Firstly, the position of the motion platform can be determined more accurately through compensation and correction of the posture of the motion platform; then, high-resolution two-dimensional focusing processing of a region of interest is realized through reverse projection, and a bistatic two-dimensional imaging result of the region of interest, namely a bistatic two-dimensional figure of the region of interest, is obtained.

Various embodiments relate to a bi-static radar system, including: first and second radar stations configured to: transmit first and second radar signals based upon a clock signal; wherein the first radar station receives a reflected second radar signal and the second radar station receives a reflected first radar signal; coherently process the reflected first and second radar signals to produce a first and second doppler frequency for first and second reference targets, wherein the first and second reference targets are is a detected target with the greatest signal strength; generate a frequency offset estimate based upon the average of the first and second doppler frequencies; frequency shift the reflected second radar signal by the frequency offset estimate to produce a corrected second radar signal; and coherently process the corrected second radar signal to produce first radar outputs from the first radar station.

The application relates to a KCF-TBD method based on a non-cooperative bistatic radar and belongs to the weak target tracking technical field of the non-cooperative bistatic radar. The application can realize detection and tracking of multiple weak targets on the basis of not depending on a motion model, and in view of the fact that in the actual scanning process of the passive bistatic radar, the capture of weak targets between frames is unstable, the KCF tracking frame is easily affected by strong clutter, errors of the tracking system itself and the like, and thus the problems of tracking frame drift and loss are caused, track prediction is carried out by using deep learning, the position of the KCF tracking frame is effectively corrected, and the stability of the tracking process is improved.

The invention discloses a multi-core DSP (Digital Signal Processor) implementation method based on a double-base STAP internal compensation architecture, which comprises the following steps of: embedding DW / ADC (Digital Waveguide / Analog to Digital Converter) compensation into a JDL (Java Data Link) dimensionality reduction STAP link in each core to finish local compensation, covariance estimation, weight solution and adaptive filtering, and implementing overlapped pipeline of'previous block calculation / next block carrying 'by adopting intra-core double-buffer dynamic multiplexing and EDMA (Enhanced Direct Memory Access) prefetching. The problems that the multi-core utilization rate is low and the real-time performance is difficult to guarantee due to repeated write-back / read-in of intermediate compensation data and inconsistent parallel granularity in the prior art are solved. According to the method, off-chip bandwidth occupation and single-frame processing time delay are remarkably reduced, the multi-core resource utilization rate and the overall throughput rate are improved, the engineering realizability of landing on a multi-core DSP platform is achieved, and the method is suitable for real-time processing of bistatic radar non-stationary clutter suppression and target detection.

The application provides a ground-based bistatic radar lunar imaging geometry correction method, device and equipment, and relates to the technical field of synthetic aperture radar. The geometry correction method comprises the following steps: constructing a two-way slant range model according to the geometric relationship between the ground-based bistatic radar and the lunar imaging area, determining the mapping relationship between the lunar geographic coordinate system and the delay-Doppler coordinate system based on the two-way slant range model; constructing an initial rational polynomial coefficient model based on the mapping relationship, projecting the delay-Doppler domain image result obtained by the ground-based bistatic radar to the lunar geographic coordinate system by using the initial rational polynomial coefficient model, and obtaining a preliminary geometry correction result; analyzing the system error of the ground-based bistatic radar, adding an affine transformation in the initial rational polynomial coefficient model according to the analysis result, obtaining an improved rational polynomial coefficient model, and projecting the delay-Doppler domain image result to the lunar geographic coordinate system again based on the improved rational polynomial coefficient model, and obtaining a final geometry correction result.

The invention discloses a bistatic radar multi-ship target separation imaging method and device. The method comprises the following steps: acquiring echo signals containing a plurality of ship targets; performing range direction processing on the echo signal to obtain a range direction processing signal; distance unit screening is carried out according to the distance direction processing signals, a reference distance unit is determined through the screened distance units, and local entropy transformation is carried out on the distance direction processing signals at the reference distance unit to obtain an entropy value curve; solving the Doppler frequency modulation rate of each ship target according to the entropy curve; constructing a coarse focusing filter by using the Doppler frequency modulation rate, and performing coarse imaging on the distance direction processing signal according to the coarse focusing filter to obtain a coarse imaging result; and obtaining a special display point image according to the coarse imaging result, constructing a separation imaging filter by using a Doppler frequency modulation rate, and carrying out separation imaging on the coarse imaging result according to the special display point image and the separation imaging filter to obtain a separation imaging result of the ship target. According to the invention, the separation imaging result of the specific ship target can be accurately extracted.

The application discloses a double-base radar space synchronization method based on clutter locking, which comprises the following steps: firstly, a double-base radar space synchronization model is established, model parameter initialization is completed, uniform sea clutter surface target echo is obtained, two-dimensional scanning is performed on the sea clutter area, echo filtering and uniformization processing are performed, the azimuth and pitch angle of the beam alignment moment are estimated, the irradiation target area is changed, multiple sets of alignment moment angles are obtained, a double-base relative position positioning equation is established, the position error of the transmitting station and the receiving station is introduced, the positioning equation is optimized and solved, the relative position of the double-base platform is obtained, the double-base beam angle is recalculated, and the double-base radar space synchronization is realized. Compared with the existing space synchronization method, the method does not depend on the precision of the aircraft platform inertial navigation system, effectively solves the problem that the double-base beam is difficult to realize space synchronization in the actual flight process in the actual working environment, and cannot use navigation information, and the inertial navigation system has a large cumulative error in the long-time flight process.

The invention discloses an aerial target multi-resolution structure information rapid reconstruction method suitable for a bistatic radar, which improves the reconstruction processing efficiency by constructing a parameterized two-dimensional primitive library, realizes low-storage high-fidelity target reconstruction of a whole aircraft point cloud by using an orthogonal projection matching characteristic, and ensures topological semantic consistency. Firstly, a parameterized two-dimensional primitive library consistent with geometric features is constructed, and edge information reconstruction errors are reduced; then, orthogonal projection data of the point cloud of the aircraft component is matched with the primitive library, an optimal two-dimensional fitting primitive is determined, and the structure and parameters of the component are deduced through geometric correspondence; and finally, global topology verification and constraint optimization are realized through secondary projection correction, and a topological semantic integrated airplane model is constructed. Compared with a traditional point cloud reconstruction method, the method can achieve online real-time processing, structural feature definition and topological connectivity are remarkably improved, and experimental verification shows that the method has excellent robustness and reconstruction precision under various resolutions.

The application relates to the technical field of bistatic radar imaging technology, in particular to an external radiation source bistatic imaging system and method under a high dynamic receiving platform. The system comprises a high dynamic receiving platform with a GPS signal receiving module, a high dynamic receiving platform attitude measuring module, a high dynamic receiving platform position error calculating module, a one-dimensional range image processing module, a range upsampling module, a grid dividing module and a reverse projection two-dimensional imaging module. First, the position of the high dynamic receiving platform can be determined more accurately through compensation and correction of the attitude of the high dynamic receiving platform; then, high-resolution two-dimensional focusing processing of a region of interest is realized through reverse projection, and a bistatic two-dimensional imaging result of the region of interest, namely a bistatic two-dimensional figure of the region of interest, is obtained.

The present disclosure provides systems, devices, apparatus, and methods, including a computer program encoded on a storage medium, for bistatic radar-aided sensing. A radar receiver receives (210) a configuration message from a radar transmitter, configuring the radar receiver to assist the radar transmitter in bistatic radar sensing. The radar receiver receives (214) radar signal reflections. In response to receiving the radar signal reflections, the radar receiver transmits (218) a radar measurement report message to the radar transmitter. The radar receiver receives (202) a radar capability query from the radar transmitter. In response to the radar capability query, the radar receiver transmits (204) a radar capability response to the radar transmitter indicating radar capabilities supported by the radar transmitter for bistatic radar sensing.

The application discloses a bistatic radar clutter spectrum generation method based on double base inner and outer scattering coefficients, and the application divides a clutter unit in a bistatic radar space; respectively calculates the ground wiping angles of each clutter unit relative to a transmitting platform and a receiving platform; calculates equivalent ground wiping angles by using a bistatic equivalent monostatic principle; confirms clutter parameters, calculates the inner clutter scattering coefficients before correction; corrects the inner scattering model by calculating the outer plane angles corresponding to each clutter unit, and obtains the corrected clutter scattering coefficients; respectively calculates space-time two-dimensional direction vectors and clutter unit echo amplitudes, and generates a clutter echo spectrum by using all the obtained echo amplitudes. The application corrects the inner scattering model by using the outer plane angles corresponding to each clutter unit, and obtains the clutter scattering coefficients under the outer plane scattering condition. The application can be used for generating corresponding clutter spectra of various clutter types, and simultaneously reduces the scattering coefficient errors in the engineering implementation process.

Frequency and timing offset estimation in bistatic radars is provided. A method of determining a frequency offset and a timing offset of a multipath signal in a bistatic radar includes receiving a first electromagnetic signal including data indicative of a transmitter location; extracting an observed multipath component from the first electromagnetic signal and for use in generating an observed frequency and an observed timing of the multipath component; determining a plurality of reflector locations in response to map data, the transmitter location, and a receiver location; performing a ray tracing algorithm in response to a virtual anchor reflector location, the transmitter location, and the receiver location to extract an expected multipath component having an expected frequency and an expected timing, and for use in determining a frequency offset in response to a difference between the expected frequency and the observed frequency and a timing offset in response to a difference between the expected timing and the observed timing.

The application relates to a method for characterizing the RCS of a heterogeneous target passive scattering, belonging to the technical field of radar and communication. Firstly, the method judges the target surface roughness type based on the Rayleigh criterion, reveals the electric wave propagation mechanism of electromagnetic wave interaction with the target, and constructs an RCS model in combination with the target scattering characteristics. Then, in combination with the target passive scattering characteristics and the bistatic radar equation, the RCS radiation direction mode caused by the target passive scattering is characterized. Then, the three-dimensional structure model is reconstructed by using the target electromagnetic parameters, and the RCS data under different frequency bands and incident angles are obtained through full-wave simulation and microwave darkroom measurement. Finally, the simulation data and the measured data are used to fit the normalized radiation direction mode, the RCS model parameters are determined, and the accuracy and effectiveness of the model are verified. The method effectively combines theoretical analysis and simulation technology, can accurately and efficiently characterize the passive scattering characteristics of a heterogeneous target, and provides strong support for the development of radar detection and stealth technology.

Provided is a bistatic radar signal reflection detector. A method includes receiving a set of radar signals incident on a set of objects. The method includes selecting a GLRT detector. The method includes determining a ratio between a maximized likelihood function of the second hypothesis model and a maximized likelihood function of the first hypothesis model. The method includes determining whether a set of angles associated with the set of radar signals are available. The method includes, in response to determining that the set of angles are available, updating a set of data associated with a set of objects. The method includes, in response to determining that the set of angles is unavailable, selecting an angle estimation method, estimating the set of angles, and tracking the set of objects.

The invention discloses a physical constraint enhanced and multi-factor driven satellite-borne GNSS-R sea surface ocean current velocity estimation combination model construction method. The method comprises the following steps: acquiring satellite-borne GNSS-R observation data and multi-source ocean environment parameter variable data; data quality control and variable parameter extraction and processing; the invention discloses a normalized bistatic radar scattering cross section physical empirical model construction method for spaceborne GNSS-R sea surface ocean current velocity estimation. A developed model simultaneously considers the comprehensive influence of multiple factors such as wind speed, ocean current, surge, rainfall, sea surface temperature and salinity on a normalized bistatic radar scattering cross section. Constructing a satellite-borne GNSS-R sea surface ocean current velocity estimation combination model, and selecting a Transform modulation diffusion algorithm to develop the ocean current velocity estimation combination model; and the performance of the combined model is verified by adopting OSCAR data. The problem of high-precision estimation of the multi-factor-driven satellite-borne GNSS-R sea surface ocean current speed is solved.

The invention discloses a radar attitude pointing method under a large double-base angle system, and the method comprises the steps: inputting a map image, and automatically recognizing a designated region according to a color threshold value; inputting six satellite orbit elements, UTC time and a target position; calculating the position of the satellite in a WGS-84 coordinate system; calculating a linear beam vector from the satellite to the target; determining three axes under a satellite body coordinate system; calculating an attitude conversion matrix according to a maximum energy principle, and calculating an attitude Euler angle from the attitude conversion matrix; and calculating the beam footprint overlapping ratio. According to the method, the vacancy of the attitude control method of the satellite-borne bistatic radar under the large bistatic angle system is filled, and the radar performance is improved; meanwhile, due to the fact that the observation angle difference is large, multi-angle target information can be conveniently obtained, the dimension and richness of data are enhanced, and higher-quality target analysis and evaluation are provided.

The invention belongs to the technical field of radar detection, and particularly relates to a dual-radar cooperative transmit-receive split simulation implementation method, which comprises the following steps of: 1, creating simulation radar models of a receiver, a transmitter and a target; 2, setting radar parameter values of a receiver and a transmitter in a radar equation; step 3, taking a dual-machine RCS value sigma B called from a database, a distance RT between a transmitter and a target, a distance RR between a receiver and the target, and a distance RL between the transmitter and the receiver as inputs, substituting the inputs into the radar equation for calculation, and obtaining a minimum detectable signal-to-noise ratio D; and 4, when the minimum detectable signal-to-noise ratio D is greater than a set threshold value, determining that the target is detectable, and otherwise, determining that the target is not detectable.

The invention provides a geometric correction method, device and equipment for moon imaging by a ground-based bistatic radar, and relates to the technical field of synthetic aperture radars. The geometric correction method comprises the following steps: constructing a two-way slant range model according to a geometric relationship between a ground-based double-station radar and a lunar imaging area, and determining a mapping relationship between a lunar geographic coordinate system and a delay-Doppler coordinate system based on the two-way slant range model; constructing an initial rational polynomial coefficient model based on the mapping relation, and projecting a delay Doppler domain image result acquired by the ground-based bistatic radar to a moon geographic coordinate system by adopting the initial rational polynomial coefficient model to obtain a preliminary geometric correction result; analyzing system errors of the ground-based double-station radar, adding affine transformation in the initial rational polynomial coefficient model according to an analysis result to obtain an improved rational polynomial coefficient model, and projecting a delay Doppler domain image result to the lunar geographic coordinate system again based on the improved rational polynomial coefficient model to obtain a delay Doppler domain image; and obtaining a final geometric correction result.

The present application relates to the field of radar technology, specifically to a turbulence measurement and correction method based on bistatic radar, comprising: obtaining radial wind speed data of at least two radars, wherein the radial wind speed data includes first radar radial wind speed data and second radar radial wind speed data; reconstructing the second-level wind speed sequence of each height layer according to the first radar radial wind speed data to obtain the turbulence intensity to be corrected; reconstructing the wind speed field of a specific height layer according to the spatial intersection beam data of the first radar radial wind speed data and the second radar radial wind speed data to obtain the reference turbulence intensity; calculating the turbulence error according to the turbulence intensity to be corrected and the reference turbulence intensity, training the data-driven model according to the turbulence error to establish the mapping relationship between the turbulence intensity to be corrected and the turbulence error, and correcting the turbulence intensity to be corrected according to the mapping relationship. Thus, the problems of low wind measurement accuracy of single laser radar in complex terrain, high cost, difficult deployment and low efficiency of multi-radar cooperation in the prior art are solved.

The invention discloses a satellite-ground bistatic radar moving target tracking-before-detection method based on a greedy strategy, and the method comprises the steps: receiving a direct wave transmitted by a satellite and a moving target reflection echo, and generating a stacked distance-Doppler graph; constructing a candidate plot set and generating a storage vector for units on the stacked distance-Doppler maps exceeding a first-level threshold; a cumulative function and a track set of all trace point vectors in the first candidate trace point set are initialized; traversing all trace point vectors in each candidate trace point set, generating an association set through storage vectors and target kinematics constraint characteristics, and determining a trace point vector which is associated with the current trace point vector and is located in the next candidate trace point set from the association set by utilizing a greedy strategy, calculating an accumulation function and a track set of the associated trace point vectors; and traversing all trace point vectors in the last candidate trace point set, and if the cumulative function value of the current trace point vector exceeds a secondary threshold, judging that the moving target is detected.