58 results about "Bistatic radar" patented technology

The invention discloses a target parameter joint estimation method based on an MCCC criterion in an impulse noise environment, and belongs to the technical field of radars. According to the method, the target function based on the TALS criterion in the PARAFAC algorithm is corrected by adopting the maximum multiple correlation entropy MCCC criterion to enable the target function to be suitable for the impulse noise environment, the PARAFAC algorithm based on the MCCC criterion is derived, the algorithm is applied to bistatic MIMO radar target parameter estimation, dependence of the FLOS method on feature index priori knowledge is broken through, and joint estimation of target parameters is achieved.

The invention provides a bistatic ISAR imaging arc section selection method for an air moving target, and relates to the technical field of bistatic radar imaging, and the method comprises the steps: obtaining the position information of a transmitting station, a receiving station and the air moving target, and converting the position information of the transmitting station, the receiving station and the air moving target into the coordinates of an earth-centered earth-fixed coordinate system; establishing a translation simulation model, a rotation simulation model and an echo model of the air moving target; the method comprises the following steps: determining a first constraint condition and a second constraint condition of a double-base-angle change rate of an air moving target according to a translation simulation model, a rotation simulation model and an echo model of the air moving target; selecting a target imaging arc section according to the earth-centered earth-fixed coordinate system coordinates of the transmitting station, the receiving station and the air moving target; therefore, the high-resolution imaging of the air moving target can be quickly and accurately obtained according to the target imaging arc segment, and the processing efficiency and the image quality can be effectively improved.

The invention provides a simulation method for a GNSS scattering signal of a sea surface wind field. The simulation method comprises the following steps: establishing a simulation model of a delay-Doppler domain mapping waveform; a compact polarization model based on a microwave scattering model is established, a polarization component of a complete polarization scattering coefficient matrix is calculated by using the complete polarization microwave scattering model, and a scattering coefficient of a compact polarization signal is obtained according to the polarization component of the complete polarization scattering coefficient matrix and a Stokes sub-vector of the compact polarization signal. The coefficient is used as a bistatic radar scattering coefficient in a simulation model of a delay-Doppler domain mapping waveform; establishing a sea wave spectrum model for obtaining a sea wave spectrum density function; and simulating by using the model to obtain a delay-Doppler domain mapping waveform. According to the method provided by the invention, the full-polarization DDM waveform of the GNSS scattering signal can be generated in the compact polarization mode, so that the hardware complexity is reduced, and sufficient and comprehensive sea surface wind field inversion information is reserved.

The invention discloses a bistatic radar high-speed target detection method based on space-time Doppler coherent accumulation, and the method comprises the steps: building a bistatic array radar system signal echo model, and carrying out the pulse compression processing of radar echo data; based on the array receiving signal, the direction matrix of the receiving beam and the corresponding weight vector, performing simultaneous multi-beam forming processing on the signal after pulse compression to obtain a signal after beam forming; constructing a beam compensation function; performing transformation compensation on the signal after beam forming by using a beam compensation function to obtain a signal after beam walking correction; performing line demodulation processing on each beam of the signal after beam walking correction to obtain a two-dimensional signal of a distance-modulation frequency domain; and detecting to obtain a target detection result. According to the method, the effects of range migration, pitching beam migration, azimuth beam migration and Doppler frequency migration can be effectively eliminated, the detection performance of the high-speed moving target is improved, and accurate positioning and speed estimation of the high-speed moving target are realized.

Phase noise reduction is described for symmetric bistatic radar. In one example, a first beat signal is generated of a second signal received at a first antenna and a third beat signal is generated at a second antenna of a first linear antenna array. A second beat signal is generated of a first signal received at a first antenna of a second linear antenna array. The first beat signal and the third beat signal are multiplied with the complex conjugate of the second beat signal to generate products that are combined to generate a phase estimation correction term that is applied to first and second sets of radar return signals.

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.

In one example, a bistatic radar receiver includes at least one first antenna configured to receive one or more jamming signals, a second antenna configured to point a scanning beam to detect one or more reflections of the one or more jamming signals from a target, and a signal processing subsystem coupled to the at least one first antenna and to the second antenna, the signal processing subsystem configured to process the one or more jamming signals and the one or more reflections to derive a range to the target from the one or more jamming signals and the one or more reflections.

The invention discloses an airborne bistatic radar clutter suppression and target accumulation detection combined implementation method, which is applied to the technical field of radars, and aims to solve the problems of range migration, Doppler migration and strong clutter noise background when an airborne bistatic radar detects a low-altitude maneuvering target. According to the method, non-stationary clutters are effectively suppressed and range migration and Doppler migration are corrected and compensated by utilizing two-stage sliding sub-aperture space-time processing, target signal reconstruction and sub-aperture segmented accumulation, so that coherent accumulation of target multi-pulse energy is realized; finally, the purposes of improving the echo signal-clutter-noise ratio and improving the maneuvering target detection performance of the bistatic radar are achieved.

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 present invention proposes a performance evaluation method for a long-distance space reflection communication system. The reflection communication system includes a transmitter, a receiver, and a reflector. The transmitter is configured to emit a transmission signal, the reflector is configured to reflect the transmission signal to obtain a reflection signal, and the receiver is configured to receive the reflection signal. The method comprises obtaining device parameters of the reflection communication system and position information of the transmitter, receiver, and reflector; calculating a basic reflection communication link budget for the reflection communication system based on a bistatic radar equation; calculating a beam pattern based on the device parameters, and calculating a correction coefficient based on the beam pattern and position information; and using the correction coefficient to correct the basic reflection communication link budget to obtain a corrected reflection communication link budget value, thereby achieving link performance evaluation.

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.

A collaborative radar sensor system having an arrangement of at least two radar sensors (10, 12) on a motor vehicle, wherein the radar sensor system is configured to transmit phase control signals between the radar sensors in order to control the high-frequency phase of the radar signals to be transmitted; in a method for calibrating the transmission of the phase control signals with corresponding phase delays (τk), the phase control signals are generated and transmitted between the radar sensors in two configurations, and radar signals are transmitted based on the generated or transmitted phase control signals, which are reflected on the same object (40) in a bistatic radar object measurement and received by another radar sensor. The phase delay (τk) of the transmission of the phase control signals is estimated based on the difference between the phase differences (ΔτM, ΔτS) determined for the two configurations between the received radar signals and the phase control signals present on the sensors.

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 present invention discloses a geometric position-related bistatic radar measurement noise covariance model. Aiming at the problem that the bistatic radar measurement noise covariance is related to the geometric position relationship between the target and the radar, a time-varying model of the bistatic radar measurement noise covariance is re-derived and constructed, accurately describing the quantitative relationship between the measurement accuracy and the geometric positions of the target, the transmitting station, and the receiving station. First, the best estimation accuracy of the signal domain time delay and Doppler frequency shift of the bistatic radar is modeled using the Cramer-Rao bound and the ambiguity function. Secondly, the time-varying correction coefficient matrix for the conversion from the signal domain to the measurement domain in the bistatic measurement form is derived. Finally, the time-varying expression of the bistatic radar measurement noise covariance is calculated. The simulation experiment verifies and analyzes that the bistatic radar measurement noise covariance is directly affected by the geometric position relationship among the target, the transmitting station, and the receiving station, and has strong practical engineering applicability.

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.