1245 results about "Radar signal processing" patented technology

The invention relates to a radar moving target Radon-fractional Fourier transform (RFRFT) long-time phase-coherent accumulation detection method, and belongs to the technical field of radar signal processing and detection. The radar moving target Radon-fractional Fourier transform long-time phase-coherent accumulation detection method includes steps of 1), performing range demodulation and pulse pressure for radar echo to complete intra-pulse accumulation; 2), initializing parameters; 3), completing long-time inter-pulse phase-coherent accumulation by RFRFT compensation distance and Doppler frequency migration; 4), traversing all search parameters and creating a distance-RFRFT domain detection unit graph; 5), performing constant false alarm rate detection for the detection unit graph; and 6), estimating movement parameters of a target and outputting movement point traces. The radar moving target Radon-fractional Fourier transform long-time phase-coherent accumulation detection method has the advantages that amplitude information and phase information of the echo of the moving target are simultaneously utilized for long-time phase-coherent accumulation, the distance and the Doppler frequency migration in a long-time accumulation procedure are compensated, background clutter and noise are effectively suppressed, an accumulation gain is increased, dim moving targets in the heavy cluster can be detected, the movement point traces of the target can be acquired, and the method has popularization and application value.

The invention relates to a sea surface micromotion target detection and feature extraction method based on short-time fractional Fourier transform (STFRFT) and belongs to the technical field of radar signal processing and detection. The method comprises the following steps: 1) sea peak identification: dividing sea clutters into sea peak sequences and sea clutter background sequences free of sea peaks; 2) sea clutter data screening: selecting the sea clutter background sequences corresponding to the minimal mean power as data to be detected; 3) FRFT domain micromotion target detection: taking the FRFT domain signal amplitude values as detection statistical quantities and comparing the detection statistical quantities with the thresholds; 4) optimal FRFT domain filtering: extracting multi-component micromotion signals by using a narrow bandpass filter; and 5) setting an optimal time window length and estimating micromotion features in the STFRFT domain. The method can automatically adapt to suppress sea clutters to improve the signal-to-clutter ratio, can effectively isolate and extract the multi-component micromotion signals, provides a new approach to sea surface weak target detection and feature extraction, and is significant in promotion and application.

The invention discloses a radar signal parallel processing method and system based on a heterogeneous multinucleated system. The method comprises the following steps: S1, initializing equipment-end parameters, opening up a task execution thread, and dividing thread grids of data processing and the dimensions of a thread block; S2, opening up a video memory space and a memory space which are needed for the signal processing; S3, acquiring data transmission and calculating time needed by signal processing of a single time, and scheduling a genetic task scheduling algorithm to obtain a task scheduling mode; and S4, acquiring laser sampling data for storing in the memory space by means of segments according to a time sequence, sending the data to a CPU and a GPU according to the task scheduling mode, mapping sampling points to each thread and performing concurrent execution according to the thread grids and the dimensions of the thread block, and scheduling a filter coefficient to perform orthogonal phase demodulation, pulse compression, moving object display, moving object detection, pulse accumulation and constant false alarm detection on the sampling data. By applying the method and system provided by the invention, the speed of a general processor in executing the signal processing is improved, and the requirement for real-time performance of radar signal processing is met.

The invention discloses a multi-fractal detection method of targets in FRFT (Fractional Fourier Transformation) domain sea clutter and belongs to the radar signal processing field. According to the conventional multi-fractal detection methods of targets in sea clutter, echo sequences in the radar time domain are processed directly, and therefore detection performance of weak moving targets in strong sea clutter background is poor. The multi-fractal detection method of targets in FRFT domain sea clutter is characterized in that fractional Fourier transformation is organically combined with the multi-fractal processing method, and the generalized Hurst index number of the sea-clutter fractional Fourier transformation spectrum is extracted to form detection statistics by comprehensively utilizing the advantage that the fractional Fourier transformation is capable of effectively improving the signal to clutter ratio of the moving target on the sea surface and the feature that the multi-fractal characteristic is capable of breaking the tether of the signal to clutter ratio to a certain extent. The detection method comprehensively utilizes the advantages of phase-coherent accumulation and multi-fractal theory and has excellent separating capability on the weak moving targets in sea clutter; and simultaneously, the method is also suitable for tracking target signals in nonuniform fractal clutter and has popularization and application values.

A method for processing signals received by a plurality of receiving antennas in a radar system, for example for road safety, which emits sequences of chirp-modulated signals, wherein the received signals are mixed with local replicas of the transmitted signals so as to generate, for each receiving antenna, a sequence of detection signals. The detection signals are subjected to Fourier-transform processing and beam-forming processing for generating values of range, azimuth, and speed for at least one obstacle or “target” detected by the radar system. The method includes an acquisition process for yielding approximate values of range and azimuth of the obstacle, and a tracking process for yielding accurate range, azimuth and speed values of the obstacle itself.

A full-face vehicular detection method for a railway tunnel lining and a device aim to avoid collision of ground penetrating radar antennas with an overhead line system and a support of the overhead line system, the detection speed is a normal running speed of a train, the antennas in full-face detection are not interfered with each other, automatic positioning is realized during detection, only ground penetrating radar signals in a tunnel need to be acquired, and a penetrating radar signal processing and analyzing method in tunnel detection is modified. The vehicular device comprises a six-channel high-speed scanning penetrating radar, a positioning portion, a laser ranging portion and data acquisition and processing software. The pulse repetition frequency of the ground penetrating radar is 3MHz, the pulse repetition frequency of each channel is 500kHz, and the scanning rate is 976scan / s. The ground penetrating radar is provided with TEM (transverse electric and magnetic field) short-horn air coupled antennas, each group of antennas realizes a double-transmission and single-receiving function, and the center frequency of the antennas is 300MHz. The ground penetrating radar antennas are mounted outside passenger train connectors, radiation surfaces of the antennas respectively face to an arch crown, arch springing and side walls, and the full-face vehicular detection method and the device are used for automatically detecting to exam the railway tunnel lining.

A radar apparatus and method for determining the range to and velocity of at least one object comprising, transmitting a plurality of RF signals, each comprising a particular frequency and being transmitted during a particular unique finite period, the plurality of signals collectively comprising at least one first subset of signals having the same frequency and at least one second subset of signals having different frequencies, receiving the plurality of signals after reflection from an object, determining a phase difference between each of the signals and the corresponding reflected signal, each piece of phase difference information herein termed a sample, organizing the samples in two-dimensions wherein, in a first dimension, all samples have the same frequency and, in a second dimension, all consecutive samples are separated from each other by a fixed time interval; processing the samples in the first dimension to determine a phase rotation frequency corresponding to the samples in the first dimension, the phase rotation frequency comprising a Doppler frequency for the at least one object, processing the samples in the second dimension to determine a second phase rotation frequency corresponding to the samples in the second dimension; the phase rotation frequency comprising Doppler frequency and range frequency for the at least one object; comparing the first phase rotation frequency to the second phase rotation frequency to distinguish range frequency from Doppler frequency of the at least one object; and converting the Doppler frequency to a velocity of the object and converting the range frequency to a range of the object.

The invention belongs to the field of radar signal processing, and discloses a missile-borne SAR sub-aperture forward squint high-order nonlinear chirp scaling imaging method. According to the method, missile-borne SAR forward squint high-order nonlinear chirp scaling imaging is achieved through sub-aperture data, and the method can be used for SAR imaging of airborne platforms or missile-borne platforms. The method mainly includes the steps of firstly, conducting distance pulse pressure and time domain walking correction on an echo signal; secondly, converting the signal into the two-dimensional frequency domain, conducting frequency domain migration correction and secondary compression, and compensating for the high order phase in the orientation direction; thirdly, leading high-order nonlinear chirp scaling disturbance factors into the orientation frequency domain, and correcting the space variability of the Doppler frequency modulation and the high-order terms in the orientation direction; fourthly, focusing an image on the orientation frequency domain through spectrum analysis. The method solves the problem of decoupling of distance orientation and the orientation focus depth problem caused by time domain walking correction, and the method can meet the requirements for different scenes and high resolution and can be used for the field of ground mapping and other fields.

An ultra wideband radar system for detecting objects where at least one of the radar system or the object is moving. The radar may be scanned in at least one dimension, which may include angle or range. The system includes a scan combiner that combines scan information in accordance with a trajectory characteristic of a moving object and / or of a moving platform on which the radar resides. Scans may be combined by integration or filtering. A fast calculation method is described wherein the scans are combined into subsets and subsets are shifted in accordance with the trajectory characteristics before further combination. The scan information is combined in accordance with trajectory characteristics to enhance the object signal to noise. Further features are described wherein the scan information is combined according to a family of candidate trajectories and / or object positions.

The invention discloses an airborne radar clutter suppression method, belonging to the technical field of radar signal processing and aiming at solving the problems of the current clutter suppression technology such as high sample requirement, large calculation amount and poor real-time performance. The implementation steps are as follows: firstly, carrying out clutter pre-processing on the received data according to the prior information of the clutter spectrum distribution to realize dimensional reduction of the space-time bidimensions and reduce the clutter freedom degree; then carrying out cascade connection low-rank adaptive processing and performing multiple filtering and multiple dimensional reduction of the space-time bidimensions on the echoed signal to realize the clutter suppression and target detection of the signals. Indicated by the results of computer simulation analysis and actually measured data processing, the invention has remarkably reduced sample requirement and calculation amount under the precondition of good performance and the filtering performance is greatly improved under the circumstance of equivalent sample requirement, thus the invention can be used in dynamic target detection.

The invention relates to a radar target intermediate frequency (IR) echo simulation system based on multi-beam amplitude-comparison angle measurement and a control method thereof, relating to the field of radar target echo simulation. The system comprises three target echo simulation boards and an arbitrary waveform generator instrument fixture, wherein the echo simulation boards are designed with a computer module PC104, a field programmable gate array (FPGA), direct digital synthesis (DDS) technique and a simulation circuit as cores; and the arbitrary waveform generator instrument fixture is designed with instrument programming control as the core. According to the invention, simultaneous 6-channel simulated target IR echo simulation of the radar of the multi-beam amplitude-comparison angle measurement system is realized, parameters of the simulated target echo such as distance, delay, echo amplitude, Doppler shift, pattern, direction pattern modulation, noise superposition and the like can be controlled, single-channel switching and output of dual-beam echo is realized, and the test use requirement of the radar signal processor of the system is met. In the invention, the arbitrary waveform generator instrument frock is utilized, thus improving the amplitude precision of the output echo signals; and the control program in the FPGA in the target echo simulation boards is designed by the soft IP core, thus providing convenience for hardware transplanting and clipping.

The invention discloses a method for processing a millimeter wave cloud radar signal. Under a boundary layer mode, a cirrus cloud mode and a rainfall mode, the millimeter wave cloud radar echo signal is acquired by a data acquiring module; a data preprocessing module is used for preprocessing data of the millimeter wave cloud radar echo signal and outputting power spectral density distribution data; a data processing module is used for processing the power spectral density distribution data and outputting base data; a data synthesizing module is used for synthesizing the base data under three detection modes and outputting final base data; and the millimeter wave cloud radar signal is processed. According to the method, the problem of insufficient detection power caused by low millimeter wave cloud radar emission peak value power of an all-solid or travelling wave mechanism can be effectively solved, the radar detection power is improved, and the method is especially suitable for fixing a vertical millimeter wave cloud radar.

The present invention relates to a radar target image detection method based on Precise ROI-Faster R-CNN, and belongs to the technical field of radar signal processing. Firstly, the radar converts echo data information into an image and constructs a training data set; then, a Precise ROI-Faster R-CNN target detection model is established and comprises a shared convolutional neural network, a region suggestion network and a classification and regression network, and an ELU activation function, a Precise ROI Pooling method and a Soft-NMS method are adopted; inputting a training data set to carryout iterative optimization training on the model to obtain an optimal parameter of the model; and finally, inputting an image generated by real-time radar target echoes into the trained optimal target detection model for testing, and completing target detection and classification integrated processing. The method can intelligently learn and extract radar echo image features, is suitable for detection and classification of different types of targets in a complex environment, and reduces processing time and hardware cost.

The invention relates to a software radar signal data processing system and a software radar signal data processing method, so as to solve the problem of poor extensibility caused by software radar frame structure limitations in the prior art. The system comprises a hardware layer, a system layer, a middle layer and an application layer, wherein the middle layer is used for realizing universality between different hardware platforms; the middle layer is located between the application layer and the system layer for providing general service for an upper layer and is provided with a general protocol stack and a standard program interface, and the middle layer comprises data receiving middleware, data transmission middleware, real-time storage middleware, signal processing middleware, data processing middleware and radar terminal display middleware; the application layer builds a signal data processing frame based on the middle layer, a radar signal data processing function is divided to multiple assemblies and modules, and functions of platform function management and radar real-time data processing are included. Through modifying the software module of the application layer in the system, the system can be reconstructed, requirements of other radar systems can be met, a complete radar signal processing process is built, the extensibility of the system is enhanced, and the use range of the system is expanded. The system and the method of the invention are applicable to the software radar field.

The invention discloses a constructing method of an airborne radar space-time two-dimensional filter based on clutter covariance matrix reconstruction, which belongs to the technical field of radar signal processing and mainly solves the problems that the existing filtering technique has high requirement on data training samples, large operand for filtering clutter and poor real-time application performance. The constructing method comprises the following implementation steps of: firstly, constructing clutter covariance matrix according to the movement velocity and working parameters of the radar; next, realizing random clutter covariance matrix reconstruction by changing space-time relevant functions and adjusting clutter bandwidth; then, designing a group of filters with different notch widths based on a Wiener filtering principle; and finally, conducting nonlinear selection to filter coefficients according to a minimum residual energy criterion so as to obtain the optimal airborne radar space-time two-dimensional filter. Simulation analysis and measured data indicate that the constructing method has better clutter inhibition performance and moving-target detection performance when processing heterogeneous clutter environmental data compared with the small degree of freedom dimension-reducing self-adaptive method.

The invention relates to a sea surface micro-motion target Radon-linear contact transformation (RLCT) long-time phase-coherent accumulation detecting method which belongs to the technical field of radar signal processing and detection. The method comprises the following steps: (1) performing demodulation and pulse compression on radar echo, and completing calculation in pulse; (2) pre-judging sea conditions and detection target types and determining long-time phase-coherent accumulation parameters; (3) adopting RLCT compensation distance and Doppler migration and calculating micro-motion target signal energy; (4) viewing and searching parameters and establishing a distance-RLCT area detection unit graph, and carrying out constant false-alarm detection on the distance-RLCT area detection unit graph; and (5) evaluating micro-motion feature parameters, and outputting motion trace points. The sea surface micro-motion target Radon-linear contact transformation long-time phase-coherent accumulation detecting method applies sea surface target micro-motion features to target detection, meanwhile utilizes range and phase information of the echo to perform long-time phase-coherent accumulation to carry out long-time phase-coherent accumulation, effectively compensates distance and the Doppler migration, improves accumulation gain, has the capacity to detect a micro-motion target in strong clutter, can obtain the motion trace points of the target, and has popularization application value.

The invention relates to a radar slightly-moving target detection method based on a Radon-linear canonical ambiguity function (RLCAF) and belongs to the technical field of radar signal processing and detection. The radar slightly-moving target detection method based on the RLCAF comprises the following steps that (1) demodulation and pulse pressure are conducted on a radar echo in the distance direction so that in-pulse accumulation can be completed; (2) the type of a target to be detected is predicted, and parameters are initialized; (3) the distance and Doppler migration are compensated through the RLCAF and signal energy of a slightly-moving target is accumulated; (4) the parameters are traversed and searched, an RLCAF domain detection unit figure is established, and constant false-alarm detection is conducted; (5) target moving parameters are estimated and moving trace points are output. According to the radar slightly-moving target detection method based on the RLCAF, the advantages of an ambiguity function and the advantages of linear canonical transformation are combined, non-uniform velocity translational motion target signals or turning target signals can be flexibly matched and accumulated in a clutter background, the signal-to-clutter ratio is improved, range migration can be compensated through the extraction of a target observation value in a distance-slow-time plane, phase-coherent accumulation for a long time is completed, the detection capacity of radar to the slightly-moving target is improved, and therefore the radar slightly-moving target detection method based on the RLCAF is wide in applicability.

A system for preventing light pollution includes one or more radar units that monitor for vehicles in a volume surrounding or containing one or more obstructions having one or more obstruction lights. A master radar detection processing unit receives sensed radar detection information from the one or more radar units with associated radar signal processing units and determines whether a vehicle is present within the monitored volume. A plurality of obstruction light controller units are interconnected in a network, such as a wireless network. Each obstruction light controller unit turns on an obstruction light when a vehicle enters the monitored volume or a failure condition exists, and turns off the obstruction light when the vehicle has vacated the monitored volume and no failure condition exists. The one or more radar units can transmit sensed radar detection information to a master radar detection processing unit via the network.

The invention belongs to the technical field of radar signal processing and discloses a multi-target clustering method for a high resolution millimeter wave radar. The method comprises the following steps of: obtaining signal-to-noise ratios of plots detected by the radar, setting a signal-to-noise ratio detection threshold, and discarding plots with signal-to-noise ratios below the signal-to-noise ratio detection threshold in the plots detected by the radar to obtain effective plots; sorting the effective plots according to the signal-to-noise ratios from high to low to obtain sorted effective plots; obtaining a relative distance and a relative angle of each effective plot and the radar and obtaining a spatial right coordinate position and a speed of each effective plot; clustering the sorted effective plots to obtain a plurality of clusters; and calculating the position, the size, and the speed of the center point of a target corresponding to each cluster. The multi-target clusteringmethod for the high resolution millimeter wave radar has the advantages of realizing a target point cloud cluster identification of the high-resolution radar, having no lag in clustering results, andcapable of accurately calculating the recognition target and the target information.

A measuring and controlling apparatus for a vehicle includes an image processing device, which is mounted on a vehicle, photographs a circumferential state of the vehicle and processes the image signal; a radar signal processing device, which radiates radio wave or light to process a receiving signal; and a control device for controlling a brake, a throttle valve or a transmission based on the output results of the image processing device and the radar signal processing device. In such a measuring and controlling apparatus for a vehicle, the respective output information of the image processing device and the radar signal processing device includes time information at the time of photographing and time information at the time of measuring and the order of the photographed time and the measured time are adjusted. Thus, even if the processing time differs between the cases where a subject to be photographed is simple and complicated, since the photographed time and the measured time can be identified, the suitable processing according to the processing time can be executed. Thus, the running state of the vehicle can be controlled with high accuracy.

The invention relates to a radar target detection method based on dual-channel convolutional neural network false alarm controllability, and belongs to the technical field of radar signal processing.The method comprises the following steps of firstly, preprocessing radar echo signals, and constructing a training data set by using signal time-frequency information and amplitude information; then,constructing a dual-channel convolutional neural network model which comprises a dual-channel feature extraction network, a feature fusion network and a false alarm controllable classifier, and inputting a training data set to carry out iterative optimization training on the dual-channel convolutional neural network model to obtain an optimal network parameter and a judgment threshold; and finally, preprocessing a real-time radar echo signal, and inputting the preprocessed real-time radar echo signal into the trained dual-channel convolutional neural network model for testing to complete target detection. The method is suitable for radar target detection in a complex environment. According to the method, radar signal multi-dimensional features are intelligently extracted and fused. The detection performance is improved. The false alarm rate control is achieved. The actual demands of radar target detection are met.

The invention discloses a VPX-platform-based radar signal processing system and an application software design method. The processing system operated in a VPX processor comprises a hybrid communication board and a universal signal processing panel. The hybrid communication board is integrated with a multi-channel AD / DA and a Virtex-7 FPGA processor and is used for frequency-modulation waveform control, signal acquisition and corresponding signal pre-stage pre-processing work, and carrying out radar work time-sequence controlling. The universal signal processing panel integrated with a multi-piece multi-core DSP6678 processing architecture is used for realizing high-performance computing, wherein the high processing capability is realized by a parallel system formed by a plurality of processors. According to the invention, the radar signal processing system with high universality and extensibility is constructed by using a VPX-architecture-based universal ruggedized computer and the high processing capability is realized by the parallel system formed by a plurality of processors. The radar signal processing system has characteristics of small size, firm structure, and good heat radiation performance and thus the radar signal processing is modularized, standardized, and universalized, so that function integration of the system under various radar mode application backgrounds.

The invention relates to a radar moving target detection method based on short-time sparse fractional Fourier transform (ST-SFRFT), and belongs to the technical field of radar signal processing and detection. The method comprises the steps of: performing radar echo demodulation and pulse compression to realize high range resolution, and selecting a range unit to be detected; performing spare time-frequency analysis parameter initialization, comprising selection of a short-time window function and a window length and design of a sparse decomposition dictionary; performing ST-SFRFT operation for spare optimization solution, thus completing high-resolution spare time-frequency representation of moving target echo; traversing all range search units, performing moving target signal spare domain detection and estimating a target moving parameter. By adopting a high-resolution spare representation method, high-resolution and low-complexity time-frequency representation of time-varying signals is realized at the time frequency-spare domain; and the method is suitable for analyzing the time varying non-stability of signals, suppresses background clutter while improving energy concentration of moving target signals, and significantly improves the radar moving target detection and parameter estimation capability.

The present invention discloses a method for sea clutter suppression and moving target detection based on FRFT domain non-coherent accumulation, and belongs to the field of radar signal processing and detecting technology. A conventional time domain clutter map cancellation technology is difficult to detect a target moving at a low speed, and under the background of strong sea clutter, signal-to-clutter ratio in a target unit is quite low and sea clutter peak is easy to cause false alarm, thus detecting performance is decreased. Therefore, a moving target detecting technology based on the FRFT provided in the invention respectively employs an FRFT domain mean value accumulation method and an FRFT domain simple pole feedback accumulation method to finish the non-coherent accumulation via iterative smoothing of FRFT domain delay data, and the technology carries out cancellation of FRFT domain signal and accumulated data to suppress the sea clutter and improve the signal-to-clutter ratio, with the amplitude of output signal being taken as detection statistics. A detector provided in the invention has an ability to detect a weakly moving target, with no need of the prior information of an optimum transformation angle, and can estimate the motion parameter of the target, being suitable for the condition of low signal-to-clutter ratio, being simple in realization and having popularization and application values.

The invention discloses a soft sparse representation-based direction of arrival (DOA) estimation method, and belongs to the technical field of radar signal processing. A soft sparse solution is calculated to estimate the orientation of a target source on the premise of sparsity by using an iterative weighted minimum variance method. The method comprises the following steps of first selecting an initial value and a regularization parameter, and determining an iteration finishing condition; then substituting the selected initial value and the selected parameter into a soft sparse representation iteration formula for iteration; and finally quitting iteration when consistency with the iteration finishing condition is achieved, obtaining the soft sparse solution, and determining the direction of an incoming wave, namely realizing the DOA estimation of a signal. According to the method, the shortcoming that a weak target can hardly be detected by the conventional DOA estimation method is overcome; a parameter selection strategy is simple, sensitivity to the selection of regularization parameter is avoided, and the method is wide in parameter selection range and high in adaptability particularly in case of no weak object; and the weak target can be detected, higher resolution is ensured, and the performance of the method is also higher than that of the conventional DOA estimation method.

A system for preventing light pollution includes one or more radar units that monitor for vehicles in a volume surrounding or containing one or more obstructions having one or more obstruction lights. A master radar detection processing unit receives sensed radar detection information from the one or more radar units with associated radar signal processing units and determines whether a vehicle is present within the monitored volume. A plurality of obstruction light controller units are interconnected in a network, such as a wireless network. Each obstruction light controller unit turns on an obstruction light when a vehicle enters the monitored volume or a failure condition exists, and turns off the obstruction light when the vehicle has vacated the monitored volume and no failure condition exists. The one or more radar units can transmit sensed radar detection information to a master radar detection processing unit via the network.

The invention discloses a self-adaption constant false alarm rate (CFAR) fusion detection method aiming at a multi-target background radar, belonging to the field of radar signal processing. Under the background that the number of interference targets is unknown and for purpose of solving the problems that the existing CFAR detection method causes the reduction of detection performances or overhigh calculation complexity, the invention provides a simple and effective self-adaption CFAR fusion detection method. The method comprises the steps: automatically determining the number of interference targets according to Gaussian distributed 3-Sigma rules; based on the evaluated number of the interference targets, effectively rejecting an interference target sample in a reference unit, removing the adverse influence of the interference targets, and fusing the remaining pure clutter sampling value to form a detection threshold. The method can be used for detecting multiple targets while meeting the CFRA, has strong false alarm control capability and multi-target resolution capability, is simple to calculate and convenient for engineering realization, and has popularization and application values.

The invention discloses a radar scanning-mode sea clutter local multi-fractal target detector, belonging to the field of processing radar signals. The working of the radar in a residing mode is supposed in the existing sea clutter local multi-fractal target detection method, thus having larger dimensionality calculation and computation workload and being lack of instantaneity. The invention can be used for carrying out multi-fractal calculation on the basis that the radar works in a scanning mode, and a primary scanning process is not needed to acquire sufficient sampling points; the calculation of each scanning period dimensionality is updated by an iterative approach, thus ensuring the instantaneity; and the fuzzy characteristics of a local multi-fractal spectrum is extracted to form detection statistic. The detector has favorable capabilities of classifying the sea clutter and the target and detecting weak targets in strong sea clutter, is suitable for tracking target signals into fractal unstable clutter, and has generalization and application value.

The invention relates to an AIS and active radar flight path fusion and recognition method and belongs to the radar signal processing technical field. The method includes the following steps that: space-time unification pre-processing is performed on all AIS flight paths and active radar flight paths in a processing period; the AIS flight paths are associated with the active radar flight paths through adopting a flight path association cost and dual-logic criterion-based flight path association algorithm; and as for AIS flight paths and active radar flight paths which are associated successfully, Bayesian reasoning-based flight path ID distribution probabilities corresponding to the active radar flight paths are updated; and active radar flight path recognition and judgment are performed according to the ID distribution probabilities, and DCI criterion-based flight path fusion is performed on the matched AIS flight paths and active radar flight paths. With the AIS and active radar flight path fusion and recognition method of the invention adopted, automatic recognition of active radar flight paths can be effectively accomplished in a dense target environment through utilizing AIS flight path information, and active radar target tracking precision can be improved.

The invention discloses a radar signal processing system based on DRFM (Digital Radio-Frequency Memory) technology and a dense target jamming generation method. A transmitting and receiving antenna receives a radar transmitting pulse, and an L-waveband microwave transmitting and receiving assembly carries out down conversion processing on a radar signal; a wideband digital radio frequency memory in a signal processing unit receives an intermediate frequency signal, and high-speed sampling and memory are carried out; an FPGA-based signal processor carries out piecewise superposition on the stored data, and an analog echo signal covering a radar detection distance range is generated; an all-digital single-sideband modulator carries out Doppler frequency shift on the echo signal; and an FPGA-based timing controller converts the echo signal through frequency shift into an intermediate frequency output signal. Delayed superposition forwarding increases the number and the density of false targets, dense target jamming approximate to noise can be realized, and functions of the DRFM, control and management and the like can be effectively realized.