59 results about "Coherent processing" patented technology

The invention discloses a joint coherent processing method for strong and weak targets of a distributed networking radar, and aims to solve the problem of poor coherent effect caused by low parameter estimation precision of an existing coherent processing method adopted by a distributed networking radar system. A coherent parameter estimation problem is converted into a cosine similarity maximization problem, so that decoherence introduced by radar splitting is compensated, a'strong target-weak target 'interactive optimization criterion is constructed, a coherent parameter roughly estimated by a strong target is utilized to compensate the phase of a weak target signal, and the phase of the weak target signal is optimized. And the signal phase is fed back and adjusted by using the synthesis effect of the weak target, so that relatively accurate parameter estimation under the condition of a low signal-to-noise ratio is realized, coherent synthesis of distance-Doppler domain signals is completed, and the detection capability of a distributed networking radar system is improved.

The invention discloses a FDA-MIMO radar multi-target distance angle joint super-resolution method and system, and mainly solves the problem that the existing phased array only depends on the angle to identify multiple targets, resulting in low resolution ability, and the implementation scheme of the method comprises the steps of obtaining FDA-MIMO radar echo data, and performing separation aliasing on the FDA-MIMO radar echo data to obtain a data matrix; performing conversion stacking on the data matrix to obtain NM * L-dimensional data, and calculating a covariance matrix of the NM * L-dimensional data; performing reverse array decoherence processing on the covariance matrix to obtain a new source signal covariance matrix; constructing a two-dimensional spatial spectrum function of a target distance and a target angle for the new source signal covariance matrix through a MUSIC algorithm; and performing spectrum peak search on the two-dimensional spatial spectrum function, and detecting a local maximum value of the two-dimensional spatial spectrum function to obtain a distance and angle joint estimation value of a plurality of targets. The method can improve the angle resolution capability of the target when the target angle interval is lower than the traditional resolution, reduces the influence of the amplitude-phase error on the resolution capability when the target distance interval is large enough, and can be used for target recognition.

The invention relates to the technical field of radar information, in particular to a ground clutter suppression method for a ground reconnaissance radar, which comprises the following steps of: firstly, establishing a clutter profile map by using echo data, judging information inside and outside a clutter according to the clutter profile map, and selecting different signal processing flows, namely, adopting a detection channel 1 outside the clutter, adopting a detection channel 2 and a detection channel 3 inside the clutter and adopting a detection channel 2 and a detection channel 3 outside the clutter; after the detection channel 1 passes through the MTD filter, clutter suppression processing is not carried out, and a detection result is output; the detection channel 2 is a coherent processing channel, firstly performs mean filtering processing, then performs coherent processing, performs clutter suppression processing through phasor mean filtering, and outputs a detection result; and the detection channel 3 is a zero Doppler processing channel and is used for detecting a low-speed target in a clutter area, compared with the prior art, the method can reduce Doppler sidelobes as much as possible on the premise of ensuring that the ground clutter height is suppressed, and has the minimum main lobe width and the minimum signal-to-noise ratio loss.

The invention discloses a high-resolution range profile feature retention enhancement method based on iterative weighted sparse decomposition, and the method comprises the steps: obtaining radar echo data collected by a radar receiver within a coherent processing time, and constructing a two-dimensional radar echo matrix composed of a range unit number and a pulse sequence number after range direction matching filtering; representing a two-dimensional radar echo matrix as a superposition relation of adding a low-rank clutter component matrix and a sparse target component matrix; based on the superposition relation, an optimization model is constructed, and the objective function of the optimization model is the sum of the weighted nuclear norm of the low-rank clutter component matrix and the L1 norm of the sparse target component matrix. According to the method provided by the invention, the adaptive weight is applied to the singular value, so that clutters are effectively suppressed under a strong clutter background, and key structure features such as the number, position distribution and relative amplitude relationship of scattering points in the target high-resolution range profile are kept.

The invention provides an acoustic signal detection system based on an echo wall mode microcavity acoustic sensor. The acoustic signal detection system can be applied to the technical field of acoustic signal sensing and detection. The acoustic signal detection system comprises an echo wall mode microcavity acoustic sensor used for performing amplitude and phase modulation on predetermined polarization modulation light to obtain output light under the condition that an external acoustic signal acts on the echo wall mode microcavity acoustic sensor and the predetermined polarization modulation light passes through the echo wall mode microcavity acoustic sensor; the detection unit is used for performing coherent processing on the output light based on the predetermined reference light to obtain two paths of target signals, and the two paths of target signals are related to the target transmission amount and the target phase amount; the processor is used for analyzing the two paths of target signals to obtain target transmission quantity and target phase quantity; and according to the target transmission amount, the target phase amount and a plurality of first target formulas, an external sound signal is obtained, and the plurality of first target formulas represent the incidence relation between the target transmission amount and the external signal and the incidence relation between the target phase amount and the external signal.

The invention discloses a subarray beam domain high-resolution spatial spectrum estimation method under an under-snapshot condition. The method comprises the following steps: step 1, uniformly dividing N-element towed linear array sonar array element frequency domain data into K subarrays; 2, performing beam forming processing on each piece of sub-array data to obtain a beam domain result of each sub-array; 3, calculating a beam domain steering vector; 4, calculating a beam domain covariance matrix; 5, realizing signal and noise power parameter estimation based on a sparse approximate minimum variance criterion; and 6, carrying out frequency band weighted summation on the estimated signal power to obtain a broadband DOA estimation result. According to the method, sub-array division dimensionality reduction, beam domain coherent processing and sparse parameter iteration estimation are combined for processing, the method has the advantages of low snapshot adaptability and high anti-interference capability, the method can be used for near-field weak signal detection of the towed linear array under multi-target interference, and effectiveness is verified through marine test data.

The invention discloses a pseudo-random PRI airborne radar multi-frame track-before-detect method based on non-uniform FFT. The method comprises the following steps: firstly, constructing an airborne radar echo model under a pseudo-random PRI framework; then, the target and clutter folding problem in the RD domain is solved under a non-uniform coherent processing framework; and finally, target detection is realized through a multi-frame DP-TBD algorithm. According to the method, radar echo data of a plurality of scanning periods are fused, incoherent accumulation of target energy is realized, and the target detection capability under the background of low signal-to-noise ratio and strong clutter is remarkably improved; meanwhile, the Doppler ambiguity problem caused by non-uniform sampling is effectively solved by using the non-uniform FFT technology, and the representation accuracy of the target signal in the frequency domain is improved.

The invention belongs to the technical field of radar imaging and unmanned system integration, and particularly relates to a synthetic aperture radar imaging system and an unmanned aerial vehicle array SAR image detection method. The unmanned aerial vehicle array SAR image detection method comprises the following steps: S1, issuing an array arrangement form, track design parameters and an imaging mode to a main control unmanned aerial vehicle; s2, the master control unmanned aerial vehicle reckons the position, spacing, flight path and beam direction parameters of each unmanned aerial vehicle; s3, issuing the baseband excitation parameter, the synchronization signal and the attitude control instruction to an unmanned aerial vehicle detection array; s4, the unmanned aerial vehicle detection array synchronously transmits radar beams and receives target echoes, and echo data is transmitted back to the signal processing node; and S5, performing coherent processing by the signal processing node, performing SAR image signal processing, and returning a target image to a ground system. According to the method, coherent synthesis of echo received by multiple front unmanned aerial vehicles and high-resolution image generation are realized, and an image result can be used for tactical identification or geographical situation perception display.

The invention relates to a radar target detection and tracking technology, and provides a sky wave over-the-horizon radar particle filter track-before-detect method in order to solve the limitation of the traditional particle filter under long-time accumulation, a virtual frame and a speed interval are divided through motion constraint to obtain a plurality of parallel processing channels, so that a coherent pulse number estimation interval is reduced, and the estimation precision is improved. And coherent processing is carried out. Meanwhile, particles are randomly generated only in a distance-Doppler unit exceeding a threshold through a unit average constant false alarm rate CA-CFAR method before particle filtering processing, and the number of particles is further reduced. According to the method, the operand is reduced, and the weak target detection and tracking capability of the OTH radar is improved. According to the method, echo data preprocessing and coherent and non-coherent processing technologies are combined, and the calculation complexity is reduced while the detection and tracking performance of the weak target under the sky wave over-the-horizon radar is improved by means based on multiple channels and a low threshold.

The invention provides an extended target phase offset coherent waveform design and efficient accumulation method. The method comprises the following steps: acquiring a pulse signal of a JFPA waveform received by a target, returning echo signals of a plurality of extended targets, and searching a target coarse velocity by using a minimum envelope entropy, constructing a matching function to perform motion compensation on the echo signal to obtain a two-dimensional time domain signal; taking the jitter initial phase of the echo signal corresponding to the reference waveform as a matched filter, and compensating the jitter initial phase of the echo signal corresponding to the coherent accumulation waveform; and designing the echo signal after initial compensation as a coherent echo signal, and performing Fourier transform on the coherent echo signal along slow time to obtain a coherent accumulation result of the target. According to the method, accurate initial phase jitter compensation is completed without target distance information, the method is suitable for an extended target, and after the echo signal of the JFPA waveform is subjected to initial phase jitter compensation, the phase is controlled to be uniform, so that the complexity of FFT coherent processing can be reduced.

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.

The present application belongs to the technical field of radar imaging and unmanned system integration, and particularly relates to a synthetic aperture radar imaging system and a UAV array SAR image detection method. The UAV array SAR image detection method comprises: S1, issuing an array arrangement form, trajectory design parameters and an imaging mode to a master control UAV; S2, the master control UAV calculates the position, spacing, flight path and beam direction parameters of each UAV; S3, baseband excitation parameters, synchronization signals and attitude control instructions are issued to the UAV detection array; S4, the UAV detection array synchronously transmits radar beams and receives target echoes, and the echo data is returned to a signal processing node; S5, the signal processing node performs coherent processing and SAR image signal processing, and returns the target image to the ground system. The present application realizes coherent synthesis of multiple front-end UAV received echoes and high-resolution image generation, and the image result can be used for tactical identification or geographic situation awareness display.

The application relates to a UAV array dynamic angle of arrival estimation method and system, which comprises the following steps: S1, acquiring array snapshot data after reference channel auxiliary synchronization and waveform compensation; S2, establishing a parameterized space-time coupling phase model in a short coherence processing interval; S3, based on the array snapshot data, obtaining a single-channel input sequence through beam forming, and estimating a radial parameter pair by using time domain atom matching filtering; S4, based on the radial parameter pair, performing common time phase compensation on the array snapshot data to obtain a compensated snapshot matrix; S5, performing two-dimensional correlation calculation by using a space-time steering atom to estimate an angle parameter pair; S6, constructing a complete space-time dictionary atom, and estimating a complex amplitude by using a least square criterion; and S7, performing successive interference cancellation to update a residual error. Compared with the prior art, the application has the advantages of keeping low signal-to-noise ratio coherence gain and significantly reducing calculation complexity.

The application belongs to the technical field of laser detection, and discloses a laser instantaneous frequency detection device and method, which comprises: a delay self-coherence module, the delay self-coherence module is connected with a laser to be detected, and is used for performing delay self-coherence processing on an output laser signal of the laser to be detected, so as to obtain a to-be-detected laser signal containing an instantaneous phase change of the output laser signal; and a quadrature detection module, the quadrature detection module is connected with the delay self-coherence module, is used for receiving the to-be-detected laser signal, performing quadrature detection on the to-be-detected laser signal, obtaining an instantaneous phase of the output laser signal, and calculating an instantaneous frequency of the output laser signal according to the instantaneous phase. The application can reduce the complexity and cost of a detection system.

The present invention provides a signal processing method, device, radar, and storage medium for a MIMO radar. The method includes: before transmitting a signal, first modulating the multiple detection signals of the MIMO radar to different phases according to different transmission channels using the basic phase during phase modulation; then controlling each transmission channel to synchronously transmit its corresponding modulated detection signal, so that the detection signals transmitted by each transmission channel are beamformed in the outer space. Compared with TDM MIMO, the signal processing method provided in this application enables each transmission channel of the radar to participate in the transmission of all detection signals, thereby improving the intra-frame transmission gain and correspondingly extending the time for coherent processing of each receiving channel, thereby extending the radar's effective range and ensuring that the radar can still take into account the angular resolution performance within a longer effective range.

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 discloses a code hopping spread spectrum communication timing synchronization method and system, and the method employs a signal detection and frame synchronization method to carry out timing coarse synchronization, can calculate the noise floor in real time according to the change of an electromagnetic environment, takes the ratio of a useful signal incoherent processing result to a noise signal incoherent processing result as a detection quantity, is not sensitive to the change of the electromagnetic environment, and is high in detection precision. The risk of signal false capture or missing capture can be effectively avoided; a timing fine synchronization method is adopted, sampling errors are estimated through a correlation peak fitting mode, real-time correction of the sampling errors is achieved through an online table look-up and time domain linear filtering method, the method has the advantages of being high in estimation precision and good in real-time performance under the low signal-to-noise ratio, meanwhile, sampling error estimation and correction are conducted in the time domain, hardware resource overhead is effectively reduced, and the method is suitable for popularization and application. The antenna can meet the requirements of long-distance and high-reliability broadband communication under low power, and can be applied to the working scenes of short-time burst communication and continuous wave communication.

The application discloses a dimension reduction processing method for space-time joint forward-looking imaging of an airborne array radar, constructs a forward-looking imaging geometric model of the airborne array radar, receives a three-dimensional echo matrix in range, azimuth and channel, then transforms data in a single coherent processing time interval into a frequency domain and compensates Doppler phase for the echo matrix, then truncates spectral effective information to obtain snapshot data after dimension reduction. Then the newly obtained space-time snapshot is applied to space-time adaptive iterative super-resolution imaging, a space-time super-resolution spectrum curve corresponding to a space-time snapshot of a range-azimuth unit is estimated, and according to a movement speed of an aircraft and antenna scanning parameters, the super-resolution spectrum curve of each range-azimuth unit is subjected to spectrum accumulation, and finally a two-dimensional forward-looking image is obtained. The application effectively compresses space-time data by truncating echo effective information in a Doppler domain, significantly reduces operation complexity, and meanwhile maintains imaging quality.

A communication method and an apparatus, which are applied to the technical field of communications. The method comprises: a first communication apparatus transmits first information, wherein the first information comprises information of a coherent processing interval supported by the first communication apparatus and / or information of a cross-coherent processing interval supported by the first communication apparatus. The information of the coherent processing interval comprises the maximum duration of the coherent processing interval and / or the maximum number of time units comprised in the coherent processing interval, the information of the cross-coherent processing interval comprises the maximum duration of the cross-coherent processing interval and / or the number of coherent processing intervals comprised in the cross-coherent processing interval, the cross-coherent processing interval comprises M coherent processing intervals, and M is an integer greater than 1. The embodiments of the present application can acquire the capability of sensing receiver devices for processing sensing signals, thus helping to improve the sensing performance.

The application discloses a time-of-flight measurement device, a storage medium and a device. The application obtains a plurality of timestamp sets collected by a TDC in an integration period, then adds the plurality of timestamp sets to obtain a plurality of fragments, performs coherent processing on the fragments to obtain a coherent timestamp set, and generates histogram data according to the coherent timestamp set, so that the count value of the timestamp corresponding to the echo signal in the histogram data remains basically unchanged, the count value of the timestamp corresponding to the noise signal is suppressed, and therefore the signal-to-background noise ratio (SBNR) of a distance detector is improved, and the accuracy of the distance detector in measuring the time of flight is effectively improved.

The invention provides a three-dimensional joint parameter estimation method based on Wi-Fi (Wireless Fidelity) beam forming feedback information (BFI). The three-dimensional joint parameter estimation method based on the Wi-Fi beam forming feedback information (BFI) is characterized in that the three-dimensional joint parameter estimation method based on the Wi-Fi beam forming feedback information (BFI) is provided; the method comprises the following steps: firstly, acquiring BFI of a direct path and a target reflection path between transceivers; secondly, constructing the BFI into a three-dimensional matrix about three dimensions of an antenna, a subcarrier and a data packet, performing smooth decoherence processing on the matrix, and calculating a covariance matrix of the smoothed matrix; secondly, performing characteristic decomposition on the covariance matrix to obtain a signal subspace and a noise subspace; and finally, constructing a spectral function, and obtaining an angle of departure (AOD) between a direct path and a target reflection path, relative time delay and relative Doppler frequency shift through spectral peak search. Based on the three parameters obtained through estimation, the method can be applied to scenes such as positioning or breathing monitoring. According to the method, complete channel state information (CSI) does not need to be accessed, the CSI can be directly extracted from the communication process, and the method has natural robustness for carrier frequency offset and sampling frequency offset, and is easier to realize large-scale popularization and application.

The invention relates to a self-adaptive sunlight-interference-resistant infrared detection method and system, and belongs to the technical field of infrared detection, and the system comprises an infrared transmitting end, an infrared receiving end, a signal preprocessing unit, a band-pass filter unit, a digital phase-locked loop unit and a controller unit. Wherein the controller unit is electrically connected with the infrared transmitting end, the infrared receiving end, the signal preprocessing unit, the band-pass filter unit and the digital phase-locked loop unit, and comprises a dynamic modulation module, a coherent processing module, a coding demodulation module, a feature extraction module, an intelligent decision module and a detection output port. According to the invention, through a cooperative mechanism of dynamic modulation, coherent demodulation and multi-feature verification, it is ensured that only a signal emitted by the system can trigger detection, so that the system can actively adapt to environmental changes and accurately identify a real signal emitted by the system and reflected by a shielded object, and therefore, the detection accuracy is improved in various severe light environments including direct sunlight. Object detection with extremely high reliability and extremely low false alarm rate is realized.

An example method for integrated sensing and communication performed by a configuring device, the method may comprise obtaining a radio frequency (RF) sensing resource pool comprising symbols partitioned by coherent processing intervals (CPIs). The method may also comprise selecting one or more CPIs from the CPIs partitioning the RF sensing resources and selecting a sensing symbol pattern for each CPI of the one or more CPIs, from the respective set of predefined sensing symbol patterns that can be used for the CPI, based on a set of RF sensing property requirements of the first sensing device. The method may further comprise configuring the first sensing device to perform the RF sensing using the selected one or more CPIs and the selected sensing symbol pattern for each CPI of the one or more CPIs.

The application discloses a high-resolution range profile feature preserving enhancement method based on iterative weighted sparse decomposition, and comprises the following steps: obtaining radar echo data collected by a radar receiver in a coherent processing time, constructing a two-dimensional radar echo matrix composed of a distance unit number and a pulse sequence array after distance matching filtering; expressing the two-dimensional radar echo matrix as a superposition relationship of a low-rank clutter component matrix and a sparse target component matrix; based on the superposition relationship, constructing an optimization model, and a target function of the optimization model is a sum of a weighted nuclear norm of the low-rank clutter component matrix and an L1 norm of the sparse target component matrix. The method of the application realizes effective suppression of clutter in a strong clutter background by applying adaptive weights to singular values, and meanwhile, key structural features such as the number, position distribution and relative amplitude relationship of scattering points in a target high-resolution range profile are maintained.

The application provides a satellite signal positioning and error correction method, system, positioning terminal and program, and belongs to the communication technical field.The method comprises the following steps: constructing a received signal model of satellite movement; using the received signal model to perform layered processing on the received signal, and using a maximum likelihood method to perform interference source position estimation under long-time observation according to the layered processing result; performing error correction on the interference source position estimation, and completing positioning and error correction on the satellite signal.The application proposes a direct positioning method under long-time observation aiming at the interference source positioning problem under the condition that the adjacent satellite received signal is a weak signal.The method considers satellite movement in the received signal model, and interference source position estimation is obtained by using coherent and non-coherent processing modes.In addition, the application also proposes an error correction algorithm aiming at satellite retransmission frequency error, and the application realizes high-precision positioning of the interference source by using the adjacent satellite weak signal.

A method for sensing includes transmitting multiple beams of coherent optical radiation at different, respective beam angles from an array of transceivers (40) mounted on a platform (20). At two or more of the transceivers, reflections of the beams are received from two or more different, respective surfaces (56, 57. 58) at different, respective orientations relative to the platform. The received reflections are processed at the transceivers coherently with the transmitted beams to extract displacement parameters of the transceivers relative to the respective surfaces. Coordinates of the platform are computed based on the displacement parameters.

This invention relates to radar target detection and tracking technology. To address the limitations of traditional particle filtering over long-term accumulation, it provides a pre-detection tracking method for skywave over-the-horizon radar. This method divides virtual frames and velocity intervals using motion constraints to obtain multiple parallel processing channels, thereby narrowing the coherent pulse number estimation interval and performing coherent processing. Simultaneously, before particle filtering, the constant false alarm rate (CA-CFAR) method ensures that particles are randomly generated only in range-Doppler cells exceeding a threshold, further reducing the particle number. This invention reduces computational load while improving the detection and tracking capabilities of OTH radar for weak targets. This invention combines echo data preprocessing with coherent and non-coherent processing techniques, improving the detection and tracking performance of weak targets in skywave over-the-horizon radar while reducing computational complexity through multi-channel and low-threshold methods.

This invention relates to an adaptive anti-sunlight interference infrared detection method and system, belonging to the field of infrared detection technology. The system includes: an infrared transmitter, an infrared receiver, a signal preprocessing unit, a bandpass filter unit, a digital phase-locked loop unit, and a controller unit. The controller unit is electrically connected to the infrared transmitter, infrared receiver, signal preprocessing unit, bandpass filter unit, and digital phase-locked loop unit, and includes: a dynamic modulation module, a coherent processing module, an encoding and demodulation module, a feature extraction module, an intelligent decision-making module, and a detection output port. This invention, through a collaborative mechanism of dynamic modulation, coherent demodulation, and multi-feature verification, ensures that only signals emitted by the system itself can trigger detection. This allows the system to proactively adapt to environmental changes and accurately identify the true signals emitted by the system and reflected by obstructed objects. Thus, it achieves extremely high reliability and extremely low false alarm rate object detection in various harsh light environments, including direct sunlight.