48 results about "Coherent processing interval" patented technology

A detection method of double-threshold constant false alarm movement object on double-base synthetic aperture radar includes finalizing distance compression of various pulse-sampling, dividing orientation time to be multiple CPI, carrying out FFT in each CPI to enter orientation frequency domain, comparing data amplitude of frequency channel at external of clutter region with the first threshold and outputting point trace, making coagulation on point trace, making Hough transform in point trace domain and making decision of the second threshold.

A radar signal target detection and display system employs feedback to produce improved detection and tracking. Portions of the radar images for each antenna channel to search for the target of interest are defined using the track state to define the center of the search region and using the track covariance matrix to define the size of the region. Moving reference processing (MRP) is performed. MRP employs a search centered on the motion state derived from the detection sent to the tracker on the previous coherent processing interval (CPI). Space-time adaptive processing (STAP) is employed on each CPI using a unique set of adaptive degrees of freedom (DOFs) derived from pre-MRP and post-MRP complex radar image amplitudes for each antenna channel.

The invention discloses a radar clutter time space adaptive pre-filtering method based on sparse recovery, comprising steps of establishing an airborne phased control array radar clutter model, wherein the airborne phased control array radar receives clutter in a detection area in a coherent processing interval, calculating the clutter on a first distance ring, successively calculating the clutter on the first distance ring and a clutter covariance matrix, setting a matrix obtained through arranging a space time guiding vectors, obtaining the airborne phase control radar clutter rank, successively calculating the space time guiding vector and the sparse recovery clutter amplitude corresponding to the clutter on the basis of the sparse recovery, obtaining the coefficient matrix of the airborne phase control radar clutter canceller, performing pre-filtering on the received clutter, obtaining the clutter vector and the target vector, successively calculating a dimension reduction matrix corresponding to the clutter, a clutter dimension reduction vector and a target dimension reduction vector, and then obtaining the adaptive optional weight when the clutter in the airborne phase control matrix radar detection area performs dimension reduction.

The invention relates to clutter intensity divided self-adaptive dynamic target detection. An M times echo data of pulse Doppler radar in a coherent processing interval is rearranged, the arranged data is divided into primary and secondary channels, wherein the auxiliary channel adopts an FFT (Fast Fourier Transform Algorithm) to process, and an auxiliary channel clutter map is established as the basis of the selection of the primary channel fir filter bank weight coefficient; the primary channel is realized by adopting the fir filter bank; and the number of the weight coefficients of each filter is 4 which respectively correspond to different ground clutter and weather clutter situations, and one of the four weight coefficients is selected as the fir filter weight coefficient of the primary channel according to the auxiliary channel clutter map. The self-adaptive dynamic target detection provided by the invention has the advantages that the primary and secondary channels are adopted to process, the auxiliary channel is processed by adopting FFT, and the primary channel is realized by adopting the fir filter bank; and the auxiliary channel clutter map is established to indicate the current clutter background of the radar, and the weight coefficient of the primary channel fir filter is selected according to the clutter intensity.

Techniques disclosed herein include systems and methods for accurately scheduling radar and radio events against each other. Specifically, a scheduling manager can schedule radar events based on scheduled radio events (wireless network communication events). A given radio schedule for a compact radar sensor can be a relatively complicated schedule, especially when the compact radar sensor operates as part of an ad hoc network. In certain embodiments, the scheduling manager identifies a radio transmission schedule of neighboring radar nodes or compact radar sensor units. Such a radio transmission schedule of neighboring nodes can include information on when neighboring nodes will be receiving or transmitting data. The scheduling manager then schedules radar events to be executed by the radar device at available times, or at times that do not overlap with scheduled radio events.

The invention provides an airborne radar real-time Doppler beam sharpening super-resolution imaging method, and belongs to the field of radar detection and imaging. Through a method of scanning-whileobtaining-while processing, Doppler beam sharpening (DBS) super-resolution imaging is realized by fast iterative weighted least squares estimation for echo signals of current adjacent coherent processintervals (CPI), and a next CPI weighted least squares estimation result is recursively updated by utilizing the spatial correlation of adjacent CPI azimuth echoes, so that the convergence speed is improved, and computational complexity is greatly reduced. Compared with a traditional DBS imaging technology, the airborne radar real-time Doppler beam sharpening super-resolution imaging method not only can effectively improve the imaging resolution, but also can reduce the iteration times, the convergence speed is improved, and the imaging resolution is ensured while the real-time capability ofimaging is met.

The invention discloses a random pulse Doppler radar angle-Doppler imaging method based on compressed sensing. The method comprises the following steps of 1, obtaining space-time compressed sampling data on the basis of a radar system; 2, performing spatial discretization treatment on Doppler frequency space and spatial frequency in the space-time compressed sampling data, and obtaining a space-time oriented dictionary; 3, on the basis of the space-time oriented dictionary, estimating a space-time power spectrum, and obtaining an angle-Doppler image containing clutter and targets. The method effectively solves the problem of target and clutter Doppler ambiguity, improves the clutter suppression and target detection performance, lowers the number of pulses transmitted by a radar system, and can transmit other radar waveforms or observe multiple angles at the same time at identical pulse coherent processing intervals, thereby effectively improving the radar time dimension complexing ability; on the condition of the identical pulse number, the Doppler resolution capability can be effectively improved; the radar waveform low intercept and capture capacity and the anti-jamming capability are stronger.

The invention discloses a double-base MIMO radar angle measurement optimization method based on a beam space. The method comprises the steps of determining a double-base MIMO radar, setting a fact that K targets exist in the detecting range of the double-base MIMO radar, and setting the number of pulses in a coherent processing interval to Q; after determining a fact that each pulse comprises thesignal matrix of the K targets, performing matched filtering, and furthermore performing a matrix signal model; designing by means of a convex optimization method for obtaining a transmitting beam matrix and receiving a beam matrix and optimizing the signal model; determining a signal sub-space, obtaining wave departure angle estimated values and wave arrival angle estimated values of the K targets; determining mapping angle values of I sampling points in an angle area thetae which is interested by a transmitting array and mapping angle values of the I sampling points in an angle area thetar which is interested by a receiving array; further obtaining the wave departure angle true values and the wave arrival angle true values of the K targets, thereby obtaining a double-base MIMO radar angle measurement optimization result based on the beam space.

The invention discloses a segmented pulse pressure intermittent sampling and forwarding interference resisting method based on a frequency agility radar, and the method comprises the steps: continuously transmitting a first preset number of pulse signals in each preset coherent processing interval; generating a plurality of first signals according to the signal corresponding to the linear frequency modulation item, and constructing a plurality of band-pass filters; receiving a first preset number of echo signals, wherein at least part of the echo signals comprise interference information; obtaining a first preset number of baseband echo signal vectors according to the echo signal, and filtering the baseband echo signal vectors by using a band-pass filter to obtain echo sub-pulse signal vectors; according to the first signal and the echo sub-pulse signal vector, obtaining an echo signal vector after segmented pulse compression, and determining an echo matrix after in-pulse accumulation; and performing coherent accumulation on the echo matrix after intra-pulse accumulation by using a two-dimensional sparse reconstruction algorithm to obtain a detection result of the target. The probability that the radar is interfered can be reduced, so that the accuracy of target detection is improved.

The invention belongs to the radar multi-false target jamming suppression technique field and relates to a jamming subspace reconstruction-based radar multi-false target jamming suppression method. The jamming subspace reconstruction-based radar multi-false target jamming suppression method comprises the following steps that: a covariance matrix R<k> of echo signals r <k> is calculated according to the echo signals r<k> which are received by a radar in a k-th coherent processing interval; a jamming subspace P<J><k> of the k-th coherent processing interval is obtained according to Q largest eigenvalues of the R<k>, wherein Q is the number of jammers in a radar observation region; jamming signal suppression is performed on the rk through using the P<J><k>, so that post-jamming suppression signals X<k> of the radar in the k-th coherent processing interval can be obtained; the variable quantity Delta f0j, k> of the Doppler frequency of a j-th jammer in a k+1-th coherent processing interval and the k-th coherent processing interval is estimated; a jamming subspace P<J><k+1> of the k+1-th coherent processing interval can be reconstructed through utilizing the P<J><k> and the Delta f0j, k; and jamming signal suppression is performed on echo signals r <k+1> of the radar in the k+1-th coherent processing interval, so that post-jamming suppression signals X<k+1> of the radar in the k+1-th coherent processing interval can be obtained.

The invention belongs to the field of radar anti-interference, and provides a CI interference suppression method based on echo preprocessing and phase-coherent accumulation in order to solve the problems that self-defense C&I interference is overlapped with a real echo time-frequency domain, and a conventional signal processing means is difficult to suppress effectively. Echo time delay is estimated through a slow time FFT method, a distance window is set to intercept an interfered echo band, and on this basis, interference suppression is achieved by preprocessing echoes, changing fast time position distribution of false targets in different repetition periods and conducting slow time phase-coherent accumulation. According to the method, real echoes and interference signals do not needto be separated by utilizing a signal processing tool, the real target detection probability is greatly improved by integrally processing echoes of a coherent processing interval, and the number of false targets is obviously reduced. The overall calculation amount of the method is not large, and engineering implementation is possible.

The invention discloses a planning method of a pulse time sequence of an LPI radar. The method mainly comprises that a radar whose detection range includes a target is determined; N pulse signals emitted by the radar within a coherent process interval are determined; according to the total number N of the pulse signals emitted by the radar within the coherent process interval, a time interval vector t of the N pulse signals is set; the radar receives echoes of the N pulse signals after that the N pulse signals emitted in the coherent process interval pass a target, and a vector S of N pulse echo signals and an amplitude-frequency response matching filtering function are obtained successively according to the time interval vector t of the N pulse signals; further a minimum and maximum Doppler sidelobe target function is constructed; and the minimum and maximum Doppler sidelobe target function is solved to obtain an optimized time interval factor t<^> of the N pulse signals. The optimized time interval vector t<^> of the N pulse signals serves as a planning result of the pulse time sequence of the LPI radar.

The invention discloses an adjustment separation radar waveform generation method, device and equipment and a medium, and the method comprises the steps: giving a basic waveform library and modulation parameters, and enabling the basic waveform library to comprise a plurality of basic waveform vectors; a coherent processing interval is taken as a period, the number of pulses of a transmitted pulse string signal in one coherent processing interval is expressed as M, generation of each pulse in the pulse string signal is decomposed into two processes of basic waveform selection and pulse modulation, a basic waveform vector corresponding to each pulse is selected from a basic waveform library, and the basic waveform vector corresponding to each pulse is selected from the basic waveform library. And modulating a basic waveform corresponding to the basic waveform vector by using the modulation parameter to obtain a radar pulse signal to be transmitted at present. According to the method, any basic waveform vector can be selected from the basic waveform library in the radar waveform generation process, and the modulation of the basic waveform corresponding to the basic waveform vector is realized by using the modulation parameter. Compared with an existing method, the method has the advantages that the calculation amount and the transmission delay are reduced while any waveform is supported, a new scheme is provided for software radar waveform generation, and the requirements for flexible waveform transformation and waveform modulation are met.

The invention provides a radar object speed tracking method based on cross-product automatic frequency control. A cross-product automatic frequency control method is used to measure target Doppler frequency difference, a measured value is sent to a loop filter, the object speed in a next coherent processing interval is predicted, and a speed tracking loop is formed. According to the method, the problem that the tracking precision relies on the resolution of rapid Fourier transform is overcome, the problem of deficiency in a data filtering function is solved, and the method is low in errors and high in precision.

The invention discloses a perimeter security radar transverse crossing target detection method and system, a medium and equipment, which belong to the technical field of radar detection, and are usedfor solving the technical problem that the existing perimeter security radar cannot effectively detect a transverse crossing target. The method comprises the steps of 1) obtaining an angle-Doppler matrix of each array element in a current coherent processing interval; 2) according to the angle-Doppler matrix, calculating a radial speed estimation value and a target angle estimation value of the target; 3) constructing a virtual array according to the radial speed estimation value and the target angle estimation value of the target, and 4) performing target detection on the virtual array. The method has the advantages that the transverse crossing target is effectively and accurately detected, vegetation clutters can be effectively suppressed, and the like.