45 results about "Pulse-Doppler radar" patented technology

The invention discloses a pulse Doppler radar target detection method and system based on a background contrast attention mechanism, and relates to the field of radar target detection. The method comprises the following steps: preprocessing data to generate a distance Doppler image; constructing a neural network based on a background contrast attention mechanism; the neural network is trained, and the trained neural network is obtained; and obtaining a detection result of a pulse Doppler image to be detected by using the trained neural network. Based on a background contrast attention mechanism, the method focuses on learning clutter distribution characteristics of a background in a distance Doppler map and inhibiting background features from a feature level, thereby improving the significance of target features. A multi-scale background learner module based on a random mask and an attention mechanism module based on background contrast are designed in a targeted manner, and JS divergence is introduced into a loss function, so that background interference can be better suppressed from a feature level, and the detection performance in a low signal-to-clutter ratio scene is improved.

The invention provides a space-based radar time domain waveform adaptive method based on reinforcement learning, and the method comprises the following steps: firstly, constructing a radar signal echo model and a radar clutter echo model according to an inter-pulse frequency modulation pulse Doppler radar; calculating a signal clutter echo distance Doppler matrix according to the radar signal echo model and the radar clutter echo model; establishing a reinforcement learning environment and introducing a reward function to obtain a large amount of reinforcement learning data pairs; taking a large amount of reinforcement learning data as input, and combining with a reinforcement learning algorithm to train the intelligent agent; and finally, outputting an optimized inter-pulse frequency modulation pulse Doppler waveform by applying the trained intelligent agent, and realizing clutter position regulation and control. According to the method, the pulse Doppler waveform of inter-pulse frequency modulation is provided, so that the radar has the capability of actively regulating and controlling the clutter position.

The invention discloses an airborne radar moving target detection method and system based on distance-Doppler characteristics, and the method comprises the steps: building an airborne pulse Doppler radar echo signal model, and generating a large number of echo signals through simulation; performing pulse compression processing and frequency domain filtering processing on the machine echo signal to obtain a two-dimensional distance-Doppler image; processing the two-dimensional distance-Doppler image to obtain a processed distance-Doppler image; a generalized target is defined, the generalized target is marked on the processed distance-Doppler image, and a marked data set is generated; training a deep neural network model by using the labeled data set to obtain a trained deep neural network model; and by using the trained deep neural network model, target detection is performed on an actual airborne pulse Doppler radar distance-Doppler image, so that the working performance of an airborne radar system under clutter and interference conditions is greatly improved, and the minimum detectable speed limitation of the system is broken through.

A comprehensive detection device for a radar seeker relates to the technical field of measurement and control, a target angular displacement forming device (1) is arranged on the right side of the ground of a microwave anechoic chamber (3), the target angular displacement forming device is connected with a PXI system in a measurement and control cabinet (5) located on the outer side of the microwave anechoic chamber through a serial port bus, and a window is arranged on the wall of the left side of the microwave anechoic chamber. A mounting clamp (16) on the sliding clamping table (4) clamps the radar seeker to be tested and drives the radar seeker to be tested to enter the microwave darkroom from the window, and the radar seeker to be tested is connected with a high-frequency unit and a signal switching unit in the measurement and control cabinet through cables to test a receiving loop; the device has the advantages that the size is small, the assembly is convenient and fast, the shielding darkroom can be used for accurate measurement in an inner field, the device can be portable and used in an outer field, and the depth of the single-pulse Doppler radar seeker can be detected.

The present invention discloses a method for estimating the target Doppler frequency based on T-IAA. The specific steps thereof include: uniformly gridding the Doppler frequency space to generate a pilot vector set; determining the range of the target Doppler frequency to be estimated; setting a transformation matrix; performing transformation processing on the received signal and the pilot vector set; estimating the target Doppler frequency by using the iterative adaptive algorithm; and statistically calculating the resolution probability of the target Doppler frequency and the root mean square error of the estimated value. Based on the received signal of the pulsed Doppler radar, the present invention forms T-IAA by setting a transformation matrix and then estimating the target Doppler frequency in the Doppler domain by using the iterative adaptive algorithm. The method of the present invention ensures achieving the super-resolution of IAA while reducing the dimension of the inverse matrix required in IAA, reducing the computational amount of the algorithm and the system complexity, and facilitating engineering implementation.

The application discloses a kind of pulse Doppler radar weather cloud clutter automatic filtering methods, belong to radar data processing technical field.The method utilizes the statistical characteristics of weather cloud clutter on radar echo spectrum diagram, and the spatial position and motion characteristics of radar track in monitoring area, realizes the automatic identification and effective elimination of weather cloud clutter, reduces false track, and improves the detection performance of radar to "low, slow and small" target.

This invention discloses a method for compressing and transmitting pulse Doppler radar image signals, comprising the following steps: S1, acquiring pulse Doppler radar RD data and performing CFAR calculations on the RD data; S2, compressing the pulse Doppler radar RD data using the CFAR calculation results; S3, transmitting the compressed pulse Doppler radar RD data; S4, forming an image from a reconstructed RD map and map subframes using the pulse Doppler radar RD data. This invention can transmit the main information contained in the RD map with minimal loss of pulse Doppler radar RD map information using a smaller bandwidth.

The application discloses a multi-target detection method in a complex electromagnetic interference environment for a pulse Doppler radar, a joint reverse diffusion process is introduced to jointly update interference samples and amplitude samples, and thus the problems of target signals being covered or submerged by interference signals, rising of a detection false alarm rate, and difficulty in effectively separating interference from targets can be overcome; a denoising score matching criterion is introduced to train a neural network of an interference score function, so as to solve the problems of high interference intensity and complex structure in multi-target detection in a complex electromagnetic interference environment; and a sparse Bayesian learning method is introduced to adaptively model a sparse structure of multi-target echo signals. The application further provides a multi-target detection device in a complex electromagnetic interference environment. The method provided by the application can realize modeling and suppression of multiple types of interference, and simultaneously improve the detection probability of multiple low observable targets in the distance and Doppler dimension, the interference suppression capability, and the system robustness in a complex electromagnetic environment.

The invention discloses a high-speed target detection method for a pulse Doppler radar, and the method is characterized in that the method comprises the following steps: 1, obtaining an echo signal, so as to obtain initial data; step 2, resampling the initial data in the slow time dimension to obtain resampled data; 3, compensating the resampling data through a speed fuzzy number matching filter to obtain corresponding correction data; 4, performing linear transformation processing on the corrected data to obtain target data; step 5, detecting the target data to construct an effective target parameter set; and 6, repeating the steps to output a final effective target parameter set. The invention further provides a high-speed target detection device. According to the method provided by the invention, the problem that the ultra-high-speed target strides a distance unit and the speed is fuzzy during multi-target detection in a complex scene can be solved, so that the high-precision estimation and detection of the ultra-high-speed multi-target distance and speed can be realized.

The invention discloses a detection and communication integrated waveform design method based on multi-sub-pulse time-polar domain joint modulation. The method specifically comprises the following steps: establishing a detection and communication integrated polarization waveform model based on a multi-sub-pulse structure; the time domain and polarization domain combined modulation technology is applied to the detection and communication integrated waveform design of a multi-sub-pulse structure, the communication information is modulated by using waveform time domain and polarization domain resources, and the communication rate is further increased by combining with the existing frequency domain and space domain communication information modulation method; a monopulse detection and communication integrated echo processing method is provided, the high Doppler tolerance of integrated waveforms is ensured, and the detection capability of a high-speed target is improved. According to the method, the communication rate is increased, the Doppler tolerance of the designed waveform is improved, and compared with traditional pulse Doppler radar echo processing, the power at the target is attenuated and slowed down along with the increase of the speed, so that high-speed target detection is facilitated.

The invention relates to the related technical field of signal processing, in particular to a signal processing method and system for a radar life detector, and the method comprises the steps: collecting a radar detection signal, and configuring a parameter judgment reference; evaluating the analysis feasibility of the pulse Doppler radar signal, and determining a local detection sub-region under the echo signal intensity distribution mark; and adjusting the sampling frequency and the detection coverage of the signal processing unit, and generating a detection report. The technical problems that signals are processed at a fixed sampling frequency and a detection range, blind analysis is still performed when the effective analysis probability of the signals is low, local signals are easily ignored under a complex terrain, and the detection reliability is difficult to guarantee are solved, an effective analysis probability evaluation mechanism is introduced, only high-probability analyzable signals are deeply processed, local detection sub-regions are locked, and the detection reliability is ensured. The technical effects of synchronously adjusting the sampling frequency and the detection coverage range, eliminating a detection blind area under a complex terrain, performing registration correction on radar scanning surface data and discrete point data, and ensuring the detection reliability are achieved.

The invention belongs to the technical field of radar height measurement, and particularly discloses an inter-pulse phase modulation radar height measurement method based on range ambiguity. The method comprises the following steps: a transmitting branch of a pulse Doppler radar altimeter transmits a pulse signal; a receiving branch of the pulse Doppler radar altimeter receives the echo signal; obtaining an echo signal after the range gate is gated, and determining a demodulation code corresponding to the range gate; and carrying out decoding identification on the echo signal of the target distance received at the distance door according to the demodulation code. According to the scheme, the technical problem of fuzzy ranging of the pulse Doppler system radar altimeter is solved.

A complex environment echo recognition method based on an invariant scattering convolutional network and LSTM, comprising the following steps: S1, establishing geometric models and electromagnetic parameter models of several typical environments; S2, based on the geometric models and electromagnetic parameter models in S1, simulating echo signals under a pulsed Doppler radar system; S3, establishing an invariant scattering convolutional network to extract characteristic data of the echo signals in S2; S4, based on the characteristic data of the echo signals in S3, establishing a training data set and a test data set; S5, establishing an LSTM network model, and inputting the training data set in S4 to train the LSTM network model; S6, using the trained LSTM model in S5 to perform classification tests on the test data set in S3. The present invention can not only reduce the complexity of signals, but also obtain high-order semantic information of signals.

The present invention discloses a distributed multi-pulse detection method based on local order statistics, comprising the following steps: initializing a distributed radar target detection system; performing square law and DMOS-CFAR processing on each radar station to obtain local statistics; maximizing the data of the Doppler channel at each radar station and calculating its probability density function; calculating a test statistic based on a likelihood ratio test using the probability density function of the maximum value of the Doppler channel data at each radar station, and transmitting the result to a fusion center via a communication link; obtaining a global optimal statistic from the local test statistic, calculating a global decision threshold based on the global optimal statistic and a false alarm rate, and finally obtaining a target detection result in a spatial resolution unit based on the threshold. The present invention significantly improves the anti-interference capability of the distributed pulse Doppler radar system and enhances the detection capability and false alarm control capability of the radar target detection algorithm under non-uniform backgrounds such as multi-false target interference and clutter edges.

The invention discloses a medium pulse repetition frequency set selection method based on an ant colony optimization algorithm and a storage medium, an optimal selection problem of a medium pulse repetition frequency set is modeled as a combinatorial optimization problem, and by introducing the ant colony optimization algorithm, on the premise of satisfying distance and speed fuzzy elimination constraints, the optimal selection problem of the medium pulse repetition frequency set can be solved. And the blind area proportion in the radar measurement space is minimized. According to the method, the optimization efficiency of the medium pulse repetition frequency set can be effectively improved, the blind area of the distance-Doppler two-dimensional space is remarkably reduced, the convergence speed and the global optimization capability of the algorithm are improved, and the method has good practical value and popularization prospect and is suitable for improving the target detection performance of a pulse Doppler radar system.

The invention discloses a pulse Doppler radar seeker signal processing method and system, and relates to the technical field of signal processing, and the method comprises the steps: obtaining a radar detection environment, constructing a thermodynamic diagram through the analysis of an environment interference frequency band, carrying out the wave frequency processing constraint of a detection fundamental wave, and generating a fundamental frequency electromagnetic detection wave; deploying a parallel detection mode, executing parallel emission and echo receiving under a time sequence on the fundamental frequency electromagnetic detection wave, executing main lobe interference filtering and multi-dimensional tensor decomposition on a received echo signal group, and determining a target signal group; and importing the target signal group into a signal processor, executing parallel processing and result fitting of the static dimension and the dynamic dimension, and outputting a radar detection result. According to the invention, the technical problems of insufficient anti-interference performance and low target detection precision of a radar seeker in a complex strong interference environment in the prior art are solved, and the technical effects of improving the target identification capability and the anti-interference performance and improving the radar detection accuracy and reliability are achieved.

The invention discloses a distributed multi-pulse detection method based on local sequence statistics. The method comprises the following steps: initializing a distributed radar target detection system; performing square law and DMOS-CFAR processing on each radar station to obtain local statistics; each radar station takes the maximum value of the data of the Doppler channel and calculates the probability density function of the data; each radar station uses a probability density function of a Doppler channel data maximum value to calculate test statistics according to likelihood ratio test, and sends the test statistics to the fusion center through a communication link; and the fusion center obtains a global optimal statistical magnitude through the local test statistical magnitude, calculates a global judgment threshold through the global optimal statistical magnitude and the false alarm rate, and finally obtains a target detection result in the spatial resolution unit according to the threshold. According to the invention, the anti-interference capability of a distributed pulse Doppler radar system is greatly improved, and the detection capability and false alarm control capability of a radar target detection algorithm under non-uniform backgrounds such as multi-false target interference and clutter edge are enhanced.

The invention discloses a ground detection method for a radar guidance assembly, and relates to the technical field of measurement and control, the ground detection device for the radar guidance assembly provided by the invention has the characteristics of small size and convenient assembly, can utilize a shielding darkroom to perform accurate measurement in an inner field, is portable to use in an outer field, can perform depth detection on a monopulse Doppler radar guidance assembly, and has a wide application prospect. The detection comprises detection of transmitter performance, a receiving loop speed channel, a receiving loop angle channel and a servo system; according to the invention, the performance of a transmitter, a receiving loop speed channel, a receiving loop angle channel and a servo system can be checked by detecting the internal and external field performance of the radar guidance assembly; according to the method, the radar guidance assembly can be detected in a distributed manner, fault positioning is facilitated, and the fault removal efficiency is improved.

This invention proposes a joint transmit-receive anti-intermittent sampling and forwarding interference (ISRJ) method based on a Riemann product manifold space. The method includes establishing a joint constrained optimization objective function for anti-ISRJ by minimizing the unmatched filtering integrated sidelobe level of the radar transmit waveform and the integrated level of the intermittent sampling and forwarding interference signal after the radar receiver performs non-matched filtering on the radar transmit waveform, subject to waveform constant modulus constraints, receive filter energy constraints, and non-matched filter peak loss constraints. The method then converts the joint constrained optimization objective function for anti-ISRJ into an unconstrained optimization objective function on a Riemann product manifold space. The method then solves the unconstrained optimization objective function to output the radar transmit waveform and the non-matched filter sequence used by the radar receiver. This method considers the joint optimization problem of the transmit waveform and receive filter, improves the anti-ISRJ capability of the pulse Doppler radar, and can simultaneously update the transmit waveform and receive filter with good convergence.

This invention discloses a radar target detection method and system under plasma sheath coverage, mainly addressing the problem of poor target detection capability in existing technologies for plasma sheath-covered target scenarios. The implementation scheme is as follows: The received pulse Doppler radar signal is obtained and pulse compression processing is performed; a sliding window is set for the compressed echo signal, and a first threshold is calculated to determine the signals within the sliding window, obtaining detection signals that pass the first threshold; the likelihood ratio function of the detection signal is obtained, and the logarithm of the likelihood ratio function is taken to obtain a weighted statistic; the detection signal is subjected to noise normalization processing, and the normalized value is substituted into the weighted statistic to obtain a detection statistic, thus obtaining a false alarm probability function; a second threshold is determined based on the false alarm probability function, and it is compared with the detection statistic to obtain the target detection result. This invention can reduce the impact of radar echo noise interference, improve the radar detection signal-to-noise ratio, and can be used for radar detection and parameter estimation of targets covered by plasma sheaths.

The present invention discloses a spatio-temporal blind synchronization method for underwater acoustic waves and airborne radar waves, which relates to the field of radar detection. The method includes: a pulsed Doppler radar generates multiple detection pulses in the air to conduct a cruising search of the sea surface; the radar uses the PRF search of multiple phase channels to sample the echo of the water surface micro-motion signal; the signal processor of the radar processes the sampled signal according to the different radial velocities of the sea clutter and the water surface micro-motion signal relative to the detection direction of the pulsed Doppler radar to obtain the acoustic time-domain waveform of the underwater acoustic wave target; the radar is controlled to hover at the intensity center according to the position of the maximum echo amplitude of the acoustic time-domain waveform, and the radar PRF parameter is adjusted according to the echo amplitude until the acoustic time-domain waveform is synchronized with the radar detection pulse, realizing the spatio-temporal synchronization and time synchronization of the underwater acoustic wave and the airborne radar wave, and providing technical support for the actual combat application of cross-media detection.

The invention discloses a multi-target detection method for a pulse Doppler radar in a complex electromagnetic interference environment, and the method introduces a joint back diffusion process to carry out the joint updating of an interference sample and an amplitude sample, and can solve problems that a target signal is covered or submerged by an interference signal, the detection false alarm rate is increased, and the interference and a target are difficult to be effectively separated. A denoising score matching criterion is introduced to train a neural network of an interference score function so as to solve the problems of high interference intensity and complex structure during multi-target detection in a complex electromagnetic interference environment. A sparse Bayesian learning method is introduced to adaptively model a sparse structure of a multi-target echo signal. The invention further provides a multi-target detection device in the complex electromagnetic interference environment. According to the method provided by the invention, modeling and suppression of various types of interference can be realized, and meanwhile, the detection probability and the interference suppression capability of a plurality of low observable targets in distance and Doppler dimensions and the system robustness in a complex electromagnetic environment are improved.

The invention discloses a radar and photoelectric combined calibration method and calibration device, and belongs to the technical field of radar calibration. According to the method, errors caused by environmental interference can be effectively avoided through the certainty of the static position, so that high-precision calibration is realized; the calibration method disclosed by the invention reveals the basic principle of radar static calibration, establishes a set of complete signal processing method, is highly consistent with the actual engineering test result, ensures the scientificity and reliability of the method, and further ensures the measurement precision and stability of the calibration method. Besides, the calibration device provided by the invention is simple in structure and low in cost, and compared with traditional calibration equipment, the calibration device does not need to be physically connected with the radar and can be flexibly placed at any position, so that the complexity of installation and use is greatly reduced. The wireless connection design not only simplifies the operation process, but also improves the applicability and portability of the device, and is generally used for external field calibration of the pulse Doppler system radar.

The application discloses a pulse Doppler radar seeker signal processing method and system, and relates to the technical field of signal processing.The method comprises the following steps: acquiring a radar detection environment, constructing a thermal map by analyzing an environmental interference frequency band, performing wave frequency processing constraint on a detection fundamental wave, and generating a fundamental frequency electromagnetic detection wave; deploying a parallel detection mode, performing parallel emission and echo reception of the fundamental frequency electromagnetic detection wave under a time sequence, performing main lobe interference filtering and multi-dimensional tensor decomposition on a received echo signal group, and determining a target signal group; and importing the target signal group into a signal processor, performing parallel processing of static dimensions and dynamic dimensions and result fitting, and outputting a radar detection result.The application solves the technical problems of insufficient anti-interference performance of a radar seeker in a complex strong interference environment and low target detection precision in the prior art, and achieves the technical effects of improving target recognition capability and anti-interference performance, improving radar detection accuracy and reliability.

A comprehensive detection device for a radar seeker relates to the field of measurement and control technology. A target angular displacement forming device (1) is provided on the right side of the floor of a microwave darkroom (3). The target angular displacement forming device is connected to a PXI system in a measurement and control cabinet (5) located outside the microwave darkroom via a serial port bus. A window is provided on the wall on the left side of the microwave darkroom. A mounting fixture (16) on a sliding clamping table (4) clamps the radar seeker to be tested and drives the radar seeker to be tested to enter the microwave darkroom through the window. The radar seeker to be tested is connected to a high-frequency unit and a signal switching unit in the measurement and control cabinet via a cable to test a receiving circuit. Then, the radar seeker to be tested is removed from the mounting fixture and placed in a shielding device to test a transmitting circuit. The invention has the advantages of small size, convenient assembly, accurate measurement in a shielded darkroom in an indoor field, and portable use in an outdoor field. It is capable of depth detection of a single pulse Doppler radar seeker, etc.

The present application relates to a kind of airborne pulse Doppler radar system signal level simulation method, the method is established radar system three-dimensional scene by STK software, then through SystemVue software builds airborne pulse Doppler radar signal level simulation model, simultaneously by simulation scene interface model and STK software connection, read the parameter information in the parameter configuration file report of the detected aircraft target in Access association, after running machine simulation model, obtain the visualized graphic simulation result of the speed and distance of the detected aircraft target of each level processing process of airborne pulse Doppler radar signal and the detection simulation result of airborne pulse Doppler radar.The present application can make the design, application, verification of airborne pulse Doppler radar system more close to actual use scene, and greatly improve the fidelity and practicality of airborne pulse Doppler radar system simulation, provide a platform for system to carry out actual confrontation environment digital verification.

The invention provides a photoelectric oscillator capable of being used for dual-frequency microwave pulse generation. The photoelectric oscillator mainly comprises a laser, a polarization controller, a dual-parallel Mach-Zehnder modulator, a single-mode fiber, a photoelectric detector, an electric amplifier, an equivalent dual-band filter and a microwave source, wherein the equivalent dual-band filter is obtained by connecting two narrow-band filters in parallel and serves as a frequency selection device of the optoelectronic oscillator system; a microwave source is utilized to excite double-frequency oscillation of a photoelectric oscillator loop, loop gain modulation is realized through active mode-locking modulation, the form of an output signal is changed, and then a pulse signal is output; compared with a traditional pulse output photoelectric oscillator, the photoelectric oscillator has the advantages of being simple in structure and tunable in dual-frequency, meanwhile, the output pulse has two center frequencies, and the photoelectric oscillator has good application in the aspects of pulse Doppler radar, detection and the like.

The invention provides a pulse Doppler radar target distance-Doppler feature modulation method based on a phase modulation surface. The pulse Doppler radar target distance-Doppler feature modulation method comprises the steps of 1, presetting a coded modulation waveform; 2, modulating the position characteristics of the false target; 3, speed characteristic modulation of the false target; and step 4, deception of the CFAR detector is carried out. The PSS-based PD radar target distance-Doppler feature modulation method is innovatively provided, and the application of the PSS in the aspect of radar target multi-dimensional feature joint modulation is expanded. According to the invention, the cost is lower, the system complexity is lower, and the electromagnetic concealment is stronger. By applying different coding waveforms to the PSS feature modulation reflector, flexible and diversified feature modulation styles can be generated, the limitation of the traditional PD radar passive feature modulation method on functions of limited effect, insufficient flexibility and the like is overcome, and the advantage of reusability of an active feature modulation technology is also taken into account.

The invention discloses a coherent suppression interference signal generation method based on optical time stretching. The method relates to the technical field of optical communication, the technical field of microwaves and the technical field of electronic countermeasures. The method comprises a mode-locked laser MLL, a dual-drive Mach-Zehnder modulator DDMZM, an arbitrary waveform generator AWG, a vector signal generator VSG, an erbium-doped fiber amplifier EDFA, a dispersion compensation fiber DCF and a photoelectric detector PD. An MLL and a DDMZM are adopted to copy a radar signal and a phase step signal in a frequency domain, controllable delay inequality is applied to the copied signal by utilizing the time stretching capability of a DCF, a coherent suppression interference signal is generated through PD beat frequency, coherent suppression interference can be carried out on a synthetic aperture radar (SAR), an inverse synthetic aperture radar (ISAR), a pulse Doppler radar and a continuous wave radar, and the method has the advantages of being simple in structure, convenient to operate and high in practicability. The requirements for transmitting power and parameter reconnaissance are reduced, the limitation of frequency bands and bandwidths of a traditional electronic interference system is overcome, and the future development trend of an electronic countermeasure system is met.

The invention discloses a three-dimensional super-resolution detection method for a pulse Doppler radar, and the method comprises the steps: 1, obtaining an echo signal, so as to obtain corresponding detection information; 2, performing discrete linear chirp transformation on the detection information, and taking an amplitude maximum value point in a transformation result as a detection unit; 3, correcting the detection parameters by adopting a Newton method, and adding the corrected detection parameters as a first effective target into an effective target set; 4, removing the detection information corresponding to the first effective target from the echo information signal, repeatedly executing the above steps to obtain a second effective target, and performing cyclic correction on the first effective target based on the second effective target; and step 5, repeating the step 2 to the step 4 to obtain a final effective target set. The invention further provides a three-dimensional super-resolution detection device. According to the method provided by the invention, the problem that the number of the cluster targets cannot be accurately estimated due to energy cross in the Doppler dimension can be solved.