74 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 discloses a satellite-borne GNSS-R important feature selection and forest above-ground biomass and canopy height estimation method in combination with a tree model ensemble learning algorithm and an SHAP interpreter. According to the method, three efficient gradient boosting decision tree algorithms, namely CatBoost, XGBoost and LightGBM, and an SHAP interpreter are combined to respectively select important features for modeling in inversion of forest above-ground biomass and canopy height; and on the basis of three tree model ensemble learning algorithms of CatBoost, XGBoost and LightGBM, a bistatic radar scattering cross section, an effective scattering area and selected important features are fused to construct a global high space-time forest above-ground biomass and canopy height estimation model. According to the method, a tree model ensemble learning algorithm and satellite-borne GNSS-R data and multivariable parameters of an SHAP interpreter are combined for collaborative inversion of the global high space-time forest above-ground biomass and canopy height, and a new forest above-ground biomass and canopy height obtaining means is provided; and a satellite-borne GNSS-R inversion forest above-ground biomass and canopy height method taking multiple influence factors into consideration is realized.

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 relates to a passive bistatic radar weak target detection system and method, and belongs to the technical field of target detection. In order to solve the problem of low detection probability of a passive bistatic radar system in the prior art, the target detection system comprises an acquisition module used for acquiring a passive bistatic radar weak target PPI image data set; the preprocessing module is used for carrying out data loading and preprocessing on the data in the data set obtained by the obtaining module; and the improved YOLOv8 network model is used for detecting the data processed by the preprocessing module. By using the detection method of the system, weak signals and background noise can be distinguished more effectively, and the detection accuracy is 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.

A method for operating a radar-based vehicle interior monitoring system is described, wherein the vehicle interior monitoring system comprises, as radar sensors, a first UWB sensor (10) with at least one antenna (11) and a second UWB sensor (20) with at least one antenna (21), as well as an evaluation unit (30). The first UWB sensor (10), the second UWB sensor (20), and the evaluation unit are interconnected for data exchange via a data bus (40). The first and second UWB sensors (10, 20) are operated as a bistable radar, wherein radar pulses emitted by the first UWB sensor (10) are received by the second UWB sensor (20) as radar echoes.The evaluation unit (30) synchronizes the radar pulses emitted by the first UWB sensor (10) with the radar echoes received by the second UWB sensor (20) before determining the channel impulse response from the emitted radar pulses and the radar echoes.

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.

The invention provides a non-cooperative bistatic radar real-time signal processing method based on a heterogeneous platform. The non-cooperative bistatic radar real-time signal processing method comprises the steps that the heterogeneous platform is built; obtaining CPU fixed memory areas corresponding to the number of GPU blocks, and creating a data interaction thread to realize parallel computing; performing data analysis through frame header identifier retrieval to obtain transmitting signal parameter information, multi-channel echo data and reference channel data, and performing calculation to obtain echo beam data; zero padding is carried out on the echo beam data and the reference channel data, matched filtering is carried out on the echo beam data after zero padding, and a distance one-dimensional image is obtained; performing fast Fourier transform calculation in the slow time dimension to obtain data after coherent accumulation; obtaining a target trace point; and sorting the target plots, grouping the sorted plots, screening plot groups by using an M / N algorithm, fusing each screened plot group into a single plot, and outputting a final target plot array. According to the invention, signals can be processed in real time, and target trace points can be output.

The invention provides a sea clutter simulation method based on an air-based bistatic radar system, and the method comprises the steps: irradiating a to-be-monitored sea surface through a radar carried on a satellite launching platform, and dividing a radar irradiation sea area in each radar coherent processing interval CPI into a plurality of sub-regions; determining a single-beam monopulse sea clutter signal corresponding to each sub-region based on the frequency domain characteristics of each sea surface scattering point in each sub-region through a sea clutter frequency domain algorithm; and according to the corresponding single-beam monopulse sea clutter signal in each sub-region, determining an echo signal corresponding to a beam in each radar coherent processing interval CPI, so that a sea clutter frequency domain algorithm can be utilized to convert relatively complex Fourier transform into frequency shift and linear calculation, the calculation amount of simulation is reduced, and the simulation efficiency is improved.

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 relates to a long-time accumulation detection method based on a bistatic radar, and the method comprises the steps: firstly constructing a bistatic radar detection model, and receiving an echo signal generated by the reflection of an external radiation source signal through a target; pulse compression, distance dimension FFT, multiplication with a frequency response function generating a distance matched filter, conjugate multiplication with an exponential term causing distance migration, distance-Doppler dimension fast Fourier transform processing, Keystone linear frequency modulation Z transform processing and distance dimension IFFT processing are sequentially carried out on the echo signal, and a fifth echo signal is obtained; and carrying out peak detection on the fifth echo signal to detect the target and obtain the motion parameters of the target. Compared with the prior art, the method has the advantages of reducing energy accumulation loss caused by quantization errors when FFT processing is not interpolated in the distance dimension, effectively completing distance migration correction and pulse accumulation, reducing operation complexity caused by long-time accumulation and the like.

The invention provides a bistatic radar system based on a superheterodyne Rydberg atom receiver. The transmitting end and the receiving end of the system are different in position and are synchronized by a timing system device. A system transmitting end transmits a linear frequency modulation signal, and a system receiving end uses a Rydberg atom receiver to receive an echo of a detection signal reflected by a target. The Rydberg atom receiver is of a superheterodyne structure, that is, a receiving end firstly generates a linear frequency modulation signal consistent with a transmitting end based on a timing system device, then inputs the linear frequency modulation signal and a received echo signal into an atom gas chamber together, then measures the spectral change of probe light penetrating through the atom gas chamber, and realizes target detection mainly according to the measured spectral change. And distance measurement and positioning. The system can utilize the advantages of high sensitivity, small size and the like of the Rydberg atom receiver, and overcomes the defect of insufficient instantaneous bandwidth of the atom receiver through special design.

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 provides a method for calculating a normalized bistatic radar cross section based on GNSS-R data, obtaining detection data collected by GNSS-R technology; performing a first preprocessing on the detection data to obtain required parameters; bringing the required parameters into a forward scattering model, performing a second preprocessing on the required parameters to obtain a normalized bistatic radar cross section; obtaining a first velocity value through the normalized bistatic radar cross section, the first velocity value being a value of the sea surface wind speed; wherein the required parameters include the received power under a delay-Doppler diagram, the total distance loss, the effective isotropic radiated power, the gain of a low-orbit satellite antenna, the unit delay value of a position within a preset distance of a mirror point, and the unit Doppler frequency shift value of a position within a preset distance of a mirror point. By calculating the sea surface wind speed through the normalized bistatic radar cross section based on GNSS-R data, the accuracy and real-time performance of wind speed measurement are improved.

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.