184 results about "Matched filter" patented technology

The invention relates to an optical cable monitoring and data analysis method and device, equipment and a medium. The method comprises the following steps: acquiring current state data of an optical fiber link, and dynamically generating adaptive pulse coding parameters and matched filter parameters based on the data by using a deep reinforcement learning agent, so as to generate and inject coded pulses into the optical fiber link; and then receiving an echo signal, performing matched filtering processing on the signal by using the generated matched filter parameter to obtain a filtering output signal, further calculating a performance index vector and a reward signal, and finally updating a strategy network of the intelligent agent by using the reward signal, thereby realizing continuous optimization of pulse coding and matched filtering parameters. Therefore, the system can automatically adapt to the dynamic change of an optical fiber link, the spatial resolution, the dynamic range and the signal-to-noise ratio are effectively improved, and the adaptive capability and the robustness of the system are enhanced at the same time.

The invention discloses a foundation pit support deformation real-time monitoring method based on edge calculation, and aims to solve the problems of multi-node time synchronization and clock drift compensation caused by unavailability or poor quality of satellite navigation and precise time protocols in an underground or shielded environment. According to the method, through event dictionary learning, partition time slot scheduling and safety coding micro excitation time synchronization, matched filtering decoding, multi-scale arrival time estimation, paired time difference robust fusion, frequency priority and phase speed limit correction and network disconnection time holding, the time synchronization efficiency is improved; the technical effects that multi-source data alignment, deformation field reconstruction and graded early warning are completed on the unified virtual reference time scale, and high-precision synchronization and online drift compensation are obtained without depending on the external time service condition are achieved.

The invention discloses a target long-time accumulation method based on ADMF (Amplitude Dimethyl Formamide) under an FDA (Frequency Division Amplification) radar area array system, which mainly solves the problem of insufficient target detection capability caused by weak received target echo energy and low signal-to-noise ratio of received signals when the existing FDA system radar realizes wide-coverage wide-area target monitoring. According to the implementation scheme, the method comprises the following steps: establishing an area array echo model combined with an azimuth-dimension FDA and a pitch-dimension phased array; constructing a time-angle two-dimensional matched filter under a plane array system in which the azimuth FDA and the pitching phased array are combined, and performing matched filtering on echo signals; performing first-order KT conversion and Doppler fuzzy compensation on the echo signal after matched filtering to realize range walk correction; and carrying out distance dimension IFFT and slow time dimension FFT on the corrected signal to obtain a signal after phase-coherent accumulation. Through long-time coherent accumulation of the target, the echo energy of the FDA radar target can be improved, the signal-to-noise ratio can be reduced, the target detection probability can be improved, and the method can be used for detecting a weak high-speed moving target.

The invention provides a carbon monoxide plume identification and quantification method based on a domestic hyperspectral satellite, and the method comprises the steps: carrying out the radiometric calibration and atmospheric correction of the data of a visible short-wave infrared hyperspectral camera AHS I carried by the domestic hyperspectral observation satellite (GF-5B, Gaofen-5 B satellite); generating a carbon monoxide unit absorption spectrum by using a medium-resolution atmospheric transmission model MODTRAN; inverting a carbon monoxide enhancement value by adopting a matched filtering method; generating a binary plume mask through threshold segmentation; and constructing a deep learning model based on a residual neural network ResNet network, and realizing plume pixel-level identification and carbon monoxide column concentration enhancement value prediction. The method can identify the carbon monoxide plume with high precision and high efficiency, and is suitable for atmospheric pollution monitoring and pollution source quantification.

The invention discloses a maneuvering target long-time coherent accumulation method, system and device and a medium, and relates to the technical field of radar signal processing, and the method comprises the steps: enabling a plane array to achieve the complete airspace coverage in the azimuth angle range dimension through the introduction of FDA; according to the planar array, three-dimensional information of a target is utilized, so that the target can obtain information with higher dimensionality than that of coherent FDA. Then, an azimuth angle-pitch angle-distance three-dimensional matching filter is designed, and rapid waveform matching is realized. The method aims at the influence of a maneuvering target phase-coherent accumulation process. And finally, compensating range migration and Doppler frequency migration in a high-altitude maneuvering target detection process by adopting a second-order Keysone transform-LVD algorithm to realize coherent accumulation of the target. The invention not only provides a novel radar array combining PA and FDA, but also is applied to the field of target detection, especially for complex detection conditions such as high-altitude maneuvering targets.

Systems and methods for anatomical identification using ultrasonic imaging and acoustic shadow detection methods are provided. At least some embodiments of the disclosure comprise the following steps: acquiring ultrasound image; detecting shadow region; extracting shadow profile; filtering shadow profile with matched filter; identifying anatomical landmarks within shadow; extracting features of anatomical landmarks; classifying anatomy, and determining with a high degree of confidence that the target anatomy is depicted in the image. A determination is made as to the degree of confidence that the target anatomy is depicted in the image. Conditionally, graphics indicating presence and position of target anatomy is displayed including disposition, location and orientation thereof.

The audio device comprises a receiver (201) arranged to receive a set of input audio signals. An audio beamformer (101) performs beamforming by combining the outputs of the filters. The feedback circuit (103) comprises a set of matched filters having a complex conjugate frequency response, and the beamforming adapter (105) adapts the filters in response to a comparison of the input audio signal and the feedback audio signal. An adaptation coefficient processor (207) determines decorrelation coefficients for a set of spatial decorrelation filters that generate a decorrelated output signal from an input audio signal, where the decorrelation coefficients are adapted based on the input signal. A set of spatial filters (205, 301, 401) is arranged to apply spatial filtering to the input audio signal or the feedback signal, wherein the set of spatial filters has coefficients determined from the decorrelation coefficients.

The invention discloses a front-feedback combined burst signal fast symbol synchronization method, which relates to the technical field of digital signal processing and satellite communication, and comprises the following steps: firstly, sampling a received signal subjected to matched filtering processing according to a 4-time symbol rate by using an initial NCO (Network Controlled Oscillator), then dividing a sampling value into two paths, sending one path to an FIFO (First In First Out) register for caching, and using Oamp in the other path; the method comprises the following steps of: firstly, performing timing deviation estimation by using an FIFO (First In First Out) register and an M algorithm, secondly, determining a moment when the FIFO register starts to read data, an oscillation initial value of an interpolation control NCO and an initial value of an interpolation coefficient according to a timing deviation estimation result, starting the interpolation control NCO, and then, sending the data read by the FIFO register into a Farrow structure interpolation filter for interpolation processing according to the initial value of the interpolation coefficient. And finally, a Gardner loop is started, feedback control is carried out on the interpolation control NCO, and an interpolation result is output, so that the fast symbol synchronization speed and precision of the burst signal are improved, and the stability and timeliness of fast symbol synchronization of the burst signal are guaranteed.

The invention relates to a computer-implemented method for determining spatially resolved radiation load information of a patient when conducting an examination with an imaging X-ray apparatus having an X-ray radiator for outputting an X-ray field for conducting the examination, wherein patient input dose information is determined for determining the radiation load information, wherein the pre-dose information is determined in the case of use of a matching filter arranged between the patient and the X-ray radiator, which causes a non-uniform dose distribution in a plane perpendicular to a central ray of the X-ray field, the pre-dose information describing a uniform distribution of the X-ray dose acting on the patient without the matching filter; dose distribution information is calculated using the pre-dose information by means of a filter model, which describes at least the dose distribution of the X-ray dose acting on the patient in the part of the X-ray field covered by the matching filter; and the patient input dose information is determined using the dose distribution information.

This invention discloses a network synchronization device that may include a matched filter. The matched filter may be configured to generate an event for synchronizing the operation of elements in the network, at least in part in response to a timing frame generated at a network switch. The event for synchronizing the operation of the element may include a first event generated at least in part in response to first information associated with a first element and a second event generated at least in part in response to second information associated with a second element. Related systems and methods are also disclosed.

A system and methods are disclosed. The method includes obtaining a seismic dataset including a plurality of recorded multiple events, generating a predicted multiple model using a multiple prediction method and the seismic dataset, and estimating a set of initial matching filters using a matching method, to match the plurality of estimated and recorded multiple events. The method further includes generating a tensor field based on the predicted multiple model, determining a set of structure-oriented matching filters based on the set of initial matching filters and the tensor field, generating a filtered multiple model based on the predicted multiple model and the set of structure-oriented matching filters, and generating a multiple-attenuated seismic dataset based on the filtered multiple model and the seismic dataset, forming a seismic image based, at least in part, on the multiple-attenuated seismic dataset, and determining a location of a hydrocarbon reservoir based on the seismic image.

The application provides a satellite navigation deception jamming identification and positioning method based on passive synthetic aperture, comprising the following steps: mounting an antenna and a deception jamming signal receiver on a moving carrier and designing the moving carrier to move at a constant speed above a deception jamming source; designing the antenna to continuously receive deception jamming signals emitted by the deception jamming source below in a horizontal beam coverage time; processing the deception jamming signals by the receiver to obtain Doppler signals; performing matched filtering of the Doppler signals r'' under different matched filter frequency conditions by using a matched filter to obtain a frequency modulation-frequency modulation-time two-dimensional search matrix; obtaining the frequency modulation of the signal r'' based on the frequency modulation-frequency modulation-time two-dimensional search matrix; calculating the radial distance between the receiver and the deception jamming signal source under the zero Doppler plane based on the frequency modulation of r''; calculating the position information of the deception jamming source based on the radial distance; and judging the deception jamming signal according to the position information of the deception jamming source.

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.

The application provides a high-efficiency beam separation method and device in an unlicensed multi-beam satellite communication system, and is applied to the technical field of satellite communication, wherein the method comprises the following steps: performing first-stage frequency conversion filtering and downsampling on a target number of subbands to obtain a coarse-grained signal; performing second-stage frequency conversion on the coarse-grained signal based on the target number of subbands to obtain two side frequency points of the subband; performing second-stage filtering and downsampling on the two side frequency points to obtain a fine-grained signal; selecting a corresponding signal branch from the fine-grained signal based on a center frequency point of each beam in a plurality of beams to perform third-stage frequency conversion filtering and downsampling to obtain a target beam signal; and performing fourth-stage matching filtering on the target beam signals corresponding to the plurality of beams respectively through a preset matching filter to obtain parallel separation signals corresponding to the plurality of beams respectively. Through the application, the calculation complexity can be reduced through step-by-step frequency conversion, and the beam extraction effect can be optimized in combination with a multi-stage filter group.

The invention discloses a high-speed maneuvering target coherent accumulation method based on scale correction time reversal transformation, and relates to the technical field of radar signal processing. The objective of the invention is to solve the problem that the real-time requirement of target identification cannot be met due to low efficiency of the existing moving target coherent accumulation method. The method comprises the following steps: obtaining a distance frequency dimension of an echo signal; constructing a scale matching filter by using the speed search parameter, thereby obtaining a pulse compression result; obtaining a time domain form of the pulse compression result after time reversal by using the pulse compression result; constructing a phase compensation function based on the speed search parameter and the acceleration search parameter, and obtaining an inter-pulse accumulation result by using the phase compensation function and a time domain form of a pulse compression result after time reversal, thereby obtaining a speed value, a distance value and an acceleration value; and obtaining an accurate estimation value of the target jerk by using the speed value, the distance value and the acceleration value. The method is used for target coherent accumulation.

The application provides a single-station moving ship active and passive cooperative positioning method based on relaxation transformation. The method comprises the following steps: a single-station synthetic aperture radar receives a plurality of frames of radiation pulse signals from a ship, obtains a pulse repetition interval sum, a time difference of arrival measurement value and a Doppler phase measurement value of the ship, and further determines a passive measurement matrix of the ship; based on the pulse repetition interval sum and the speed and position of the ship, a theoretical measurement matrix of the ship is determined to construct a ship positioning model, a weighted least square method and a semi-positive definite relaxation transformation algorithm are used for solving, and a predicted position and a predicted speed of the ship are obtained; a radar wave is emitted to the predicted position of the ship to obtain a scene echo of the ship; a matched filter is designed to coarsely focus the scene echo and extract a peak value signal, the peak value signal is inversely focused and inverted, and a ship echo signal is obtained; the ship is imaged by using the echo signal, and an actual position of the ship is determined according to an imaging result.

An antenna calibration system and method use a transmitter antenna array and a receiver antenna array. Calibration automatically initiates in response to a trigger condition. Each receiver antenna in the receiver antenna array receives frequency-modulated signals from the transmitter antenna array. Optionally, the transmitter antenna array transmits signals of increasing frequency ("up chirps") and / or signals of decreasing frequency ("down chirps"). The frequency-modulated signals are processed through matched filters to determine filter responses. The phase differences for each receiver antenna are calculated based on the filter responses. Calibration coefficients for each receiver antenna are generated based on the calculated phase differences. The phase of signals received from the receiver antennae are then adjusted using the respective calibration coefficients.

The application discloses a kind of detection communication integrated collision avoidance sonar signal design method and device, its method includes: modulating continuous frequency phase shift keying signal CFPSK, generates initial frequency and Chirp signal;Modulate continuous frequency phase shift keying signal, BPSK signal is modulated to Chirp by phase modulation two-way, then two-way signal is added, obtains final transmitting signal;After CFPSK signal is pulse width modulated, it is emitted by the transducer of collision avoidance sonar;Collecting collision avoidance sonar original echo signal, obtains original echo data;Original data collected is preprocessed, and two-way signal of virtual and real is obtained;Signal is compressed into short pulse bandwidth signal, generates the impulse response parameter of two groups of matched filters, each group is matched with virtual and real two-way signal to obtain four groups of matching results, and the final matching output is obtained from real number field to complex number field;The starting point of CFPSK signal is determined by detecting the peak position of matched filter output, and echo signal is accurately intercepted from received signal for communication decoding, and coherent detection is carried out on received signal and reference carrier.The application realizes the cooperative work of detection and communication function.

The invention relates to a phase noise compensation method and a distributed optical fiber sound wave sensing system. The method comprises the following steps: S1, simultaneously receiving a light source phase noise signal and a coherent receiving signal of a scattering signal for sensing through a group of coherent receivers; s2, performing low-pass and high-pass filtering on the coherent receiving signal, and extracting a light source phase noise reference signal and a sensing signal; s3, on the basis of the phase noise reference signal, respectively performing phase noise extraction and reconstruction on the transmitted detection optical signal and the local oscillation optical signal in the coherent receiving process; s4, compensating phase noise introduced by local oscillation light according to the reconstructed phase noise signal, and performing time domain and frequency domain reconstruction on the detection light signal to obtain a matched filtering kernel function after phase noise compensation; and S5, carrying out signal demodulation based on the coherent receiving signal after phase noise compensation and the reconstructed matched filtering kernel function. Compared with the prior art, high-precision phase noise compensation can be realized under the condition of low complexity.

The application provides a SAR image target detection method based on SAR image sparse enhancement and Bayesian saliency detection; comprising: step one: inputting a matched filter SAR image, obtaining initial values of regularization parameters of a SAR sparse enhancement method by calculating gray statistical characteristics of the image; step two: solving a convolution sparse feature enhancement algorithm model based on L1 norm by using an alternating direction multiplier method, and obtaining a SAR sparse enhancement image; step three: calculating a Bayesian saliency map of the SAR sparse enhancement image, binarizing the saliency map by using a threshold detection method, and realizing final target detection. The method can reduce SAR speckle noise by using a sparse image enhancement method, reduce background gray values, highlight target regions by using a SAR image saliency detection method, further reduce background pixel values, and finally realize efficient detection of ground and sea surface targets of interest.

The invention provides a signal capturing method based on maximum frequency offset constraint and dynamic DFT (Discrete Fourier Transform) or FFT (Fast Fourier Transform) selection, and belongs to the technical field of signal capturing. S2, determining a maximum frequency offset range and a target frequency point number; s3, DFT or FFT is dynamically selected; s4, peak detection is conducted on the frequency domain correlation result of the target frequency point, if the peak value is larger than a preset detection threshold, the S1 is executed again, and if yes, capturing succeeds, the frequency domain correlation result of the target frequency point is directly calculated through DFT in the scene with the relatively small frequency offset range, the calculation amount of FFT is reduced, the high efficiency of FFT is reserved in the scene with the relatively large frequency offset range, and the capturing efficiency is improved. According to the method, a target frequency point is extracted, a frequency domain correlation result corresponding to the target frequency point is extracted, whether DFT or FFT is selected, prior knowledge of a frequency offset range is utilized to limit a frequency domain detection range, a false peak value of a non-target frequency point is inhibited, and the false alarm probability and the calculation complexity are reduced.

The embodiment of the application relates to the technical field of cognitive radar, and provides a cognitive radar constant modulus waveform design method and device based on maximum signal-to-clutter-noise ratio, the method comprising: obtaining a feedback signal echo obtained after a cognitive radar transmitting signal, wherein the feedback signal echo comprises a target echo component and a clutter echo component, the target echo component is output after the transmitting signal is convolved with a unit impulse response of a target, and the clutter echo component is output after the transmitting signal is reflected by a clutter scattering point; calculating a signal-to-clutter-noise ratio of an output signal after a matched filter based on the feedback signal echo; obtaining an optimal energy spectrum density of the transmitting signal when the signal-to-clutter-noise ratio is maximum under a preset energy constraint condition; and determining a target constant modulus signal waveform based on the optimal energy spectrum density. Therefore, the radar waveform is dynamically adjusted through the interaction between the radar and the environment, better adaptability is achieved in a complex clutter environment, the balance between time domain and frequency domain characteristics is maintained, and target detection performance is improved.

The application provides an optical fiber sensing signal processing method and device for external disturbance and electronic equipment, and belongs to the technical field of distributed optical fiber acoustic wave sensing. The method comprises the following steps: collecting back-reflection light of a chirp light pulse in an optical fiber and photoelectric conversion to obtain an electrical signal corresponding to multiple sampling positions of the optical fiber; performing multi-subband matched filter processing on the electrical signal to output multiple scattered signals covering all sampling positions and having different frequencies; completing distance alignment and phase alignment for the multiple scattered signals of each sampling position in sequence to obtain multiple target scattered signals; constructing corresponding normalized weights according to time-averaged amplitudes of the target scattered signals; performing weighted coherent superposition on the multiple target scattered signals of each sampling position by using the normalized weights to generate a fused scattered signal; and demodulating the fused scattered signal to obtain differential phase information representing external disturbance of the optical fiber. The application can be applied to optical fiber acoustic wave sensing scenes such as structure monitoring, security and protection, and earthquake exploration.

A system and method for generating synthetic high-frequency seismic data for subsurface imaging comprises injecting a first seismic shot having a low frequency into a surface region and receiving reflected waves at a plurality of seismic receivers. Seismic traces are recorded and processed to generate a low-frequency seismic shot gather. A second seismic shot having a high frequency is injected, and a sparse number of high-frequency traces are recorded. A computing device resamples the low-frequency traces to match the sparse high-frequency dataset and applies a one-dimensional (1D) local matching filter to transform the low-frequency traces into simulated high-frequency traces. The transformed dataset is used to generate a high-resolution subsurface image of geological interfaces. The system enables computationally efficient high-frequency seismic data synthesis, optimizing seismic inversion accuracy while reducing acquisition costs and computational overhead.

The application discloses a SAR polar coordinate imaging method and device based on flat flight equivalence, and the method comprises the following steps: constructing a flat flight equivalence slant range model of a large oblique SAR to obtain a baseband echo signal formed by target area scattering; performing distance direction matched filter processing on the baseband echo signal to obtain a signal after range pulse compression; sequentially performing Dechirp processing, two-dimensional resampling processing and IFFT transformation on the signal after range pulse compression to obtain a SAR polar coordinate primary imaging result; and performing geometric correction on the primary imaging result based on reverse projection to obtain an imaging result without geometric deformation and with good focusing. The SAR polar coordinate imaging method based on flat flight equivalence provided by the embodiment avoids the problem of azimuth translation invariance caused by diving through slant conversion, solves the problem that the traditional PFA is not applicable to diving SAR, and successfully extends the PFA imaging algorithm without deformation to diving SAR by correcting the geometric deformation problem caused by diving.

The application relates to the technical field of radar signal processing, and discloses a time-frequency domain combined pulse compression processing method for long-pulse high-resolution wind measurement, which comprises the following steps: long-pulse echo data is acquired and subjected to local time-frequency block processing; a theoretical track of a candidate distance unit in a time-frequency plane is constructed according to a propagation time delay; track time-frequency coefficients are extracted, and a frequency domain consistency factor, a local time-frequency energy focusing factor and a Doppler consistency factor are calculated; combined compression weights are generated; the amplitude of a time domain matched filter output is adjusted and the phase information is kept; combined pulse compression output is obtained; and Doppler spectrum estimation is carried out to obtain radial wind speed information. According to the application, the long-pulse echo data is subjected to local time-frequency block processing, and a theoretical track is constructed, so that the frequency domain consistency factor and the local time-frequency energy focusing factor are calculated, thereby reducing distance sidelobe leakage and improving distance resolution capability.

This reception device comprises: a reception unit that receives, as a reception signal, a transmission signal transmitted from a transmission device; a matching filter unit that limits the bandwidth of the reception signal to the bandwidth of the transmission signal; and a Doppler shift estimation / correction unit that estimates and corrects the Doppler shift of the reception signal. The matching filter unit is disposed downstream of the Doppler shift estimation / correction unit.

The invention discloses an equivalent radiation power test method and device based on multipath separation, and a medium. The equivalent radiation power test method comprises the following steps: S1, establishing a received signal model; s2, determining an impulse response function of a matched filter; s3, determining a linear frequency modulation signal bandwidth; s4, performing matched filtering on the received signal; and S5, equivalent radiation power measurement: after time domain separation of the direct wave and each multipath signal is realized through S1 to S4, the direct wave signal power of a receiving end can be detected, a power calibration table of source signals with different powers after matched filtering is established, the signal power before matched filtering can be obtained by querying the calibration table, and the equivalent radiation power of the receiving end can be obtained. And calculating ERP (equivalent radiation power) in combination with the spatial radio frequency link. The technical problem that the equivalent radiation power test precision is not high due to the multipath effect under the ground open site condition at present is solved.

This invention discloses a method for non-integer multiple sampling rate transformation based on a digital matched filter. The method includes the following steps: calculating the phase adjustment value related to the non-integer multiple sampling rate transformation based on the input-output sampling frequency relationship; determining the phase adjustment accuracy based on the input-output sampling frequency relationship; designing a digital filter based on the phase adjustment accuracy to obtain the digital matched filter impulse response value; and using the phase adjustment value as an index of the digital matched filter impulse response value to perform matched filtering calculations, thereby realizing the non-integer multiple sampling rate transformation. This invention significantly reduces the complexity of digital filter design, saves development time and costs, and offers high flexibility and effectiveness for systems requiring fractional multiple transformation and matched filters in communication systems.

The invention provides a multi-order sideband-based multi-resolution distributed optical fiber acoustic wave sensing method, which comprises the following steps of: generating a detection light pulse comprising a plurality of linear frequency modulation sidebands with different sweep bandwidths, and injecting the detection light pulse into a sensing optical fiber; receiving a Rayleigh backscattering signal generated in the sensing optical fiber to obtain an electric signal containing vibration information distributed along the sensing optical fiber; matching filter banks corresponding to a plurality of linear frequency modulation sidebands with different frequency sweeping bandwidths are adopted, parallel matching filtering processing is carried out on the electric signals, a plurality of distributed sound wave sensing signals with different spatial resolutions are decoupled from the electric signals, and the spatial resolutions are determined by the frequency sweeping bandwidths corresponding to the linear frequency modulation sidebands; based on a plurality of distributed sound wave sensing signals with different spatial resolutions, multi-resolution sound wave vibration monitoring along a sensing optical fiber is realized.