8 results about "Coherent processing interval" patented technology

A precipitation scanning aperture RADAR system comprises at least one transmitting satellite (TX) and a plurality of receiving satellites (RXs) flying in a multi-static formation. The TX emits fixed frequency, pseudo-random, non-repeating phase modulated RADAR energy. Range and Doppler information is extracted from reflected signals received by the RXs to form coherent 2D along track / vertical images, which are combined into a 3D reflectivity map using a power-based incoherent modeling algorithm, such as a Gaussian mixture model. Embodiments implement a spotlight mode in which, for each RX, a plurality of the coherent 2D images obtained during successive coherent processing intervals (CPIs) are incoherently combined, and the satellites adjust their orientations between each CPI to compensate for satellite movement. Inter-satellite timing synchronization of 10 ns or better is sufficient for forming the 3D reflectivity map. The range and Doppler information can be extracted by concurrently demodulating at a plurality of reference frequencies.

This invention discloses a method for identifying dragged interference based on the transmit-receive spatial frequency spectrum, belonging to the field of radar signal processing technology. The invention includes: constructing an FDA-MIMO radar transmitter array and receiver array; calculating the transmitted signal of the transmitter array elements according to a preset frequency increment; receiving the target and interference echo signals of the receiver array, obtaining the target and interference signal vectors within a CPI; calculating the echo covariance matrix based on the target and interference signal vectors, and estimating its Capon spectrum; accumulating the Capon spectrum of multiple coherent processing intervals, then performing peak search to obtain the trajectory of the target and interference, and segmenting the trajectory; calculating the Euclidean distance between peaks within each trajectory, and calculating its variance to identify dragged interference. This invention utilizes the difference in trajectory characteristics between dragged interference and real targets in the transmit-receive spatial frequency spectrum domain of the FDA-MIMO radar, and distinguishes dragged interference from real targets by the magnitude of the trajectory variance without needing to estimate the target velocity.

The invention discloses a multi-static radar physical target and active false target identification method, and belongs to the field of target identification and interference resistance. The method comprises the following steps: estimating deception parameters of a target in a plurality of coherent processing intervals on the basis of measurement information based on a multi-static radar, so as to combine and form a deception parameter vector; according to the characteristic that physical target deception parameters approximately obey zero mean Gaussian distribution, variance is calculated, and a reference vector is constructed; mapping the deception parameter vector and the reference vector to a matrix manifold or a power spectrum manifold; adopting total Bregman divergence and three types of geometric metrics thereof to define a geometric distance; calculating a geometric distance between the target mapping point and the reference point; and comparing the result with a threshold value to realize the discrimination of the physical target and the false target. According to the method, the separability of physical target and false target distribution is enhanced by utilizing information geometric measurement, and the discrimination performance is remarkably improved; the method can achieve excellent performance under the condition of a small number of samples, adapts to real-time countermeasure requirements, and is high in target recognition robustness and controllable in complexity.

The invention relates to a local mismatched filter design based on a radar communication integrated waveform. The local mismatched filter design comprises the following steps: acquiring M discrete transmitted waveform vectors planned to be transmitted within a coherent processing interval; constructing a weighted summation optimization problem model based on the M transmitted waveform vectors; carrying out iterative solution on the optimization problem model by adopting an alternating direction multiplier method, and outputting M local mismatched filter coefficient vectors; wherein the M local mismatched filter coefficient vectors are respectively matched with the M discrete transmitted waveforms, and are used for carrying out filtering processing on the received echo signal at a receiving end of the radar communication integrated system so as to suppress distance sidelobe modulation and improve the moving target detection performance. The method can be applied to receiving end processing, the RSM effect can be fundamentally suppressed, clutter responses of different pulses can be effectively aligned and cancelled in cancellation processing, and therefore the moving target detection capacity of a system under the strong clutter background is remarkably improved.

The invention discloses a clutter suppression method based on low-rank approximate point iteration, which comprises the steps of processing radar echo data to obtain baseband data containing clutter signals, processing the baseband data containing the clutter signals according to a set coherent processing interval, constructing a distance Doppler two-dimensional matrix and obtaining a sparse expression of the distance Doppler two-dimensional matrix; and finally, carrying out iterative solution according to a low-rank approximate point iterative algorithm, substituting the solved data into a distance Doppler two-dimensional matrix, and carrying out parameter detection and estimation on the distance and the speed of the target. According to the scheme, the sparse characteristic of the target and the low-rank performance dual constraint of clutter are utilized, the moving target detection probability is improved by adopting a low-rank approximate point iteration method, the problem of moving target detection under the influence of clutter in a complex natural environment can be solved while clutter signals are effectively suppressed, the clutter signal suppression effect is effectively improved, and the moving target detection efficiency is improved. And the target discovery probability is greatly improved.

A radar system includes a radar receiver configured to receive return signals reflected from within a volume of radar coverage. A processor for processing the return signals extracts characteristics from a return signal received in a corresponding coherent processing interval. The extracted characteristics include a set of frequencies and / or a set of times, each frequency and / or time having a respective extracted amplitude of a corresponding set of extracted amplitudes. The processor determines a corresponding amplitude index for each extracted amplitude; and for each extracted amplitude, respectively stores in a memory location addressable via the corresponding amplitude index, a set of return signal related data including information for identifying the corresponding frequency and / or time, and an associated identifier for uniquely identifying, in combination with the amplitude index, that set of return signal related data.

The invention discloses a faint target detection method and device and a medium, and relates to the technical field of radar signal processing and time frequency control. The method comprises the following steps: implementing a time-frequency discipline on a near-end reference through an atomic clock, and establishing a phase-stable reference across a coherent processing interval; echo signals are collected in a segmented mode according to coherent processing intervals, range walk correction and phase compensation are carried out on echoes of all segments according to the motion state of the platform, and coherent accumulation in the segments is achieved; calculating a phase continuity quality factor; based on the phase continuity quality factor, performing adaptive selection between coherent splicing and semi-coherent power superposition to obtain a cross-segment synthesis result; and performing likelihood fusion and constant false alarm detection on the cross-segment synthesis result in a statistical layer, and outputting a target existence judgment and parameter estimation result. According to the invention, a high coherence retention rate can be maintained and a false alarm can be stably controlled in the presence of platform maneuvering and environmental disturbance, so that the first detection probability and the continuous tracking capability of a long-distance low observable target are improved.

The invention provides an MIMO radar maneuvering target trajectory tracking method and device, and belongs to the field of array signal processing. The method comprises the steps that echo signals collected by a multiple-input-multiple-output radar in a single coherent processing interval are constructed into a third-order data tensor, the tensor is divided into a plurality of sub-blocks along the time dimension, and a discrete estimation result of a target direction of arrival is obtained; based on the estimation result, fitting kinematic model parameters of the target to obtain initial values of dynamic trajectory parameters of the target; and then dynamic trajectory parameters are solved through structured alternating nonlinear least square iteration, and a direction-of-arrival trajectory of the target in a coherent processing interval is obtained in combination with a kinematic model. According to the method, the motion rule of the target is directly fused into the signal model, a complete track is obtained through one-time calculation of the whole batch of data, high-precision and high-reliability tracking can still be achieved when the target motion is complex and the signal is weak, and the problem that a traditional method fails due to target motion is solved.