43 results about "Coherence (signal processing)" patented technology

The invention discloses a bridge expansion joint acoustic monitoring method based on a beam forming microphone array, and the method comprises the steps: synchronously collecting acoustic signals through multiple channels, and achieving the high-precision signal alignment through clock offset compensation; the noise analysis module is started by combining a pre-triggering signal of a vehicle passing through the detection unit, the optimal microphone distance is dynamically determined according to sound field coherence and a signal-to-noise ratio maximization model, and a stepping motor drives a movable microphone to achieve real-time adjustment. On the basis, a spatial filtering weight is generated by adopting a self-adaptive beam forming algorithm, and directional enhancement and interference suppression of the expansion joint sound source are realized. Through collaborative optimization of a hardware structure and a signal processing method, the sensitivity and accuracy of acoustic monitoring of the bridge expansion joint are effectively improved, the abnormal sound source recognition capability can be remarkably enhanced, the environmental noise interference is reduced, and the method is suitable for intelligent monitoring and diagnosis of the long-term service state of the bridge expansion joint.

The invention belongs to the technical field of human body electroencephalogram signal processing and brain regulation and control, and provides a multi-modal coupling type closed-loop electrical stimulation sleep synergy signal regulation and control device and system.The technical scheme includes that multi-modal physiological signals including EEG slow wave power, cerebral blood flow and cerebrospinal fluid flow signals are obtained; screening and preprocessing the obtained multi-modal physiological signal to obtain a preprocessed multi-modal signal; calculating the time domain correlation between the EEG slow wave power and the cerebral blood flow and the frequency domain coherence between the cerebral blood flow and the cerebrospinal fluid flow signal; introducing regulatory factors of time domain correlation of EEG slow wave power and cerebral blood flow and frequency domain coherence of cerebral blood flow and cerebrospinal fluid flow signals to obtain a signal stimulation intensity calculation formula; and optimizing the signal stimulation intensity by combining a signal stimulation intensity calculation formula and the constructed double-layer optimization architecture to obtain the optimized signal stimulation intensity. And an accurate sleep regulation and control signal is generated.

The invention discloses a coherent interference-based coaxial transceiving line scanning three-dimensional profile measurement system and method. The system comprises a low-coherence light source; the beam splitter is used for collimating light emitted by the low-coherence light source and then dividing the light into two paths; the measuring light is focused into a linear light beam through the cylindrical lens and is emitted to the surface of the to-be-measured sample, and the measuring light reflected by the surface of the to-be-measured sample returns to the beam splitter along the original path; the reference light is emitted to a reference mirror with a certain inclination angle and is reflected back to the beam splitter through the reference mirror; the measuring light reflected by the surface of the sample to be measured and the reference light reflected by the reference mirror are subjected to beam combination interference through a beam splitter and are imaged to enter a camera for interference pattern acquisition; the signal processing system is used for processing the interference patterns to obtain height distribution of the to-be-measured sample on a line field, and three-dimensional profile measurement of the to-be-measured sample is realized by transversely moving or transversely scanning the to-be-measured sample and overlapping the interference patterns measured at different positions. Therefore, high-efficiency measurement can be realized while the micro-nano precision is kept.

The invention discloses a coal mine tunneling roadway advanced geological exploration and ground stress inversion method, particularly relates to the technical field of seismic signal processing in geophysical exploration, and is used for solving the problems of geological exploration signal distortion and insufficient stress inversion precision caused by strong noise interference of tunneling equipment in the prior art. Rock mass vibration signals are collected through an optical fiber sensor arranged on a roadway wall, equipment noise characteristics are identified through spectral analysis, a quantitative mapping relation between working condition parameters and noise characteristics is established, a noise reference time period is determined according to the quantitative mapping relation, a spatial coherence characteristic template is constructed, high-coherence noise components are inhibited through template comparison, and the noise reference time period is determined according to the spatial coherence characteristic template. Finally, the geological structure and stress field distribution in front of the working face are inverted based on the purified seismic wave signals, a stress concentration area and a disaster risk area are identified, the signal-to-noise ratio of the seismic signals in the strong noise environment and the reliability of the geological inversion result are effectively improved, and accurate technical support is provided for safe mining of a coal mine.

The invention relates to the technical field of radar signal processing, and discloses an anti-multipath interference vehicle-mounted millimeter wave radar signal processing method, and the method comprises the steps: obtaining a radar echo signal, and decomposing the radar echo signal into a plurality of overlapped sub-band signals in a frequency domain; constructing a static environment Doppler manifold curved surface by using self-vehicle motion data, and calculating a theoretical phase evolution model according to the static environment Doppler manifold curved surface; extracting an actual measurement phase difference between the sub-bands, and carrying out coherent accumulation on the actual measurement phase difference and the theoretical model to generate a manifold consistency coherence coefficient; direction-of-arrival estimation is carried out on each sub-band signal, and the spatial spectrum drift statistical dispersion of an angle estimation value is calculated; and generating a target multipath confidence score according to the manifold consistency coherence coefficient and the spatial spectrum drift statistical dispersion, and executing a suppression decision on a radar detection target. According to the invention, by introducing a kinematics physical constraint and broadband space stability detection mechanism, false targets generated by a multipath effect are effectively identified and eliminated, and the environmental perception precision and robustness of the vehicle-mounted radar are improved.

The invention relates to the technical field of radar interference high-speed transmission, in particular to an SAR (Synthetic Aperture Radar) interference method based on high-speed data transmission, which comprises the following steps of: receiving a radio-frequency signal transmitted by an interfered SAR, performing down-conversion and analog-to-digital conversion on the radio-frequency signal by a radio-frequency receiving front end to obtain an original sampling data stream, and transmitting the original sampling data stream to a programmable logic part through a high-speed serial interface; the method comprises the following steps: extracting pulse description words including pulse arrival time, pulse width, pulse repetition interval and carrier frequency, reconstructing a coherent interference signal baseband waveform in real time according to the pulse description words, and performing digital up-conversion and digital pre-distortion processing on the baseband waveform to generate a target interference intermediate frequency digital signal; and after digital-to-analog conversion and up-conversion are completed, an interference radio frequency signal is radiated. According to the method, data transmission and signal processing delay can be reduced, interference signal coherence is guaranteed, and intermediate frequency signal generation precision and processing real-time performance are improved.

The invention discloses a self-adaptive overlapped framing and variable window phase measurement method, device and system based on signal state perception, and belongs to the technical field of digital signal processing and phase measurement. Aiming at the technical problems that a fixed overlapping ratio and a single window function are adopted in an existing phase measurement method, resolution ratios of a time domain and a frequency domain cannot be considered under a time-varying signal, and frequency spectrum leakage and phase jump are easily introduced, the invention provides a joint self-adaptive preprocessing method. The method comprises the following steps: firstly, framing collected signals, and judging whether the signal state is a steady state or an unsteady state according to smoothness detection of absolute value sums of adjacent sampling points; according to the determined signal state, adaptively configuring an overlapping rate between adjacent data frames and window function type parameters, and then, before fast Fourier transform is carried out, introducing a window function coherent gain compensation mechanism to eliminate an amplitude reference error caused by window type switching; and finally calculating the phase difference based on the corrected spectrum result. According to the method, the overlapping framing and window function parameters are adaptively adjusted according to the signal state, the phase measurement continuity is ensured, the phase measurement precision and stability under the multi-frequency signal are improved, and the method has good real-time performance and engineering application value.

The application relates to a digital multi-beam synthesis method, which calculates weighting coefficients in real time through an FPGA signal processing unit and delivers the weighting coefficients to a digital beam forming unit, so that the beam pointing direction is adjusted in real time, thereby solving the problem that the flexibility of the beam pointing direction is limited. Meanwhile, in the digital multi-beam forming process, the beam coherence synthesis, pointing direction, width and sidelobe level are controlled through a beam forming matrix, so that spatial filtering and interference suppression are realized, the flexibility of beam forming is improved, the anti-interference capability of the system is enhanced, and through real-time adjustment of the beam parameters, the system can better adapt to a complex electromagnetic environment and improve the anti-interference performance of the system. Through real-time calculation and delivery of the weighting coefficients by the FPGA signal processing unit, the digital beam forming unit performs beam forming in the digital domain, and the complexity and delay of signal processing can be effectively reduced.

The invention relates to the technical field of signal processing, in particular to a gas ultrasonic flowmeter signal processing method and device, equipment and a medium. Determining the signal-to-noise ratio, the main peak saliency and the waveform coherence of the sound wave signal based on the sound wave signal; determining a signal quality index of the sound wave signal according to the signal-to-noise ratio, the main peak saliency and the waveform coherence; determining a reconstruction strategy of the sound wave signal according to the signal quality index and a preset decision range; performing signal reconstruction on the sound wave signal according to a reconstruction strategy to obtain a reconstructed signal; and determining a propagation time based on the reconstructed signal so as to determine the gas flow of the target flow point. The anti-interference performance of the signal waveform of the time-difference-method gas ultrasonic flowmeter under the complex working condition can be enhanced, the measurement accuracy of the propagation time is improved, and the measurement of the gas flow is more accurate.

The present invention provides a method and system for simulating delayed Doppler mapping of sea ice GNSS scattered signals, including: utilizing a scattering calculation module to determine the total scattering coefficient of each linearly polarized channel based on an electromagnetic scattering model; utilizing a GNSS scattered signal processing module to generalize the total scattering coefficient of each linearly polarized channel to obtain a fully polarized coherent model, thereby obtaining the dual-station radar cross sections for all polarized channels; and utilizing a fully polarized DDM waveform generation module to generate a DDM waveform based on GNSS signal parameters and the dual-station radar cross sections for all polarized channels. By combining the electromagnetic scattering model of sea ice with the DDM simulation of the GNSS system, the present invention overcomes the problem of the model having only a single polarization, clarifies the different polarization response characteristics of GNSS signal reflections from the sea ice surface and open water, and constructs a fully polarized DDM combination using a polarization coherence matrix, thus breaking through the limitation of traditional GNSS-R systems that only use left-hand circular polarization.

The invention provides a traveling wave fault location signal identification method, system and device and a medium, and relates to the technical field of signal processing and fault diagnosis, and the method comprises the steps: carrying out the orthogonal decomposition of a traveling wave fault location signal, extracting a high-frequency orthogonal component, constructing a polar coordinate system time sequence mapping graph based on the high-frequency orthogonal component, and carrying out the recognition of the traveling wave fault location signal. And further extracting a rotation angle sequence and a track overlapping distribution feature, extracting a topology invariant in combination with a continuous coherence algorithm, and finally judging a signal type through an evolution trend of the Warisstein distance. Thus, the integrity and accuracy of traveling wave ranging signal feature extraction can be remarkably improved, the problem of high-frequency non-stationary signal analysis is effectively solved, meanwhile, the robustness and reliability of signal recognition are enhanced through introduction of topological invariants, and therefore precise classification and judgment of complex signals are achieved. The method is helpful for improving the precision and efficiency of fault positioning, and is suitable for rapid identification and monitoring of typical faults such as partial discharge in a complex power system.

The invention relates to the technical field of signal processing, and discloses an anti-electromagnetic interference processing method and system for a sensor, and the method comprises the steps: carrying out the multi-stage electromagnetic shielding processing of an original mixed signal, and obtaining an initial anti-interference signal; based on the high-order statistical characteristics of the initial anti-interference signal, performing adaptive blind source separation on the initial anti-interference signal to obtain a vibration response signal and an electromagnetic interference reference signal; performing time-frequency domain transformation on the vibration response signal, and identifying a dominant vibration mode component from the transformed vibration response signal; performing coherence analysis on the dominant vibration mode component and the electromagnetic interference reference signal to obtain a coherence coefficient matrix; based on the coherence coefficient matrix, performing cancellation filtering on the dominant vibration mode component and the electromagnetic interference reference signal to obtain an anti-interference vibration signal; performing phase delay compensation on the anti-interference vibration signal to obtain a final anti-interference vibration signal; the anti-electromagnetic interference efficiency of the sensor can be improved.

The present application relates to radar interference high-speed transmission technical field, specifically for SAR radar interference method based on high-speed data transmission, including: receiving the radio frequency signal of the interfered synthetic aperture radar transmission, the original sampling data stream is obtained through the down conversion and analog-digital conversion of radio frequency receiving front end, through high-speed serial interface transmission to programmable logic part, the pulse description word containing pulse arrival time, pulse width, pulse repetition interval, carrier frequency is extracted, the baseband waveform of coherent interference signal is reconstructed in real time according to pulse description word, the target interference intermediate frequency digital signal is generated by carrying out digital up conversion and digital predistortion processing to baseband waveform, and the interference radio frequency signal is radiated after completing digital-analog conversion and up conversion through high-speed serial interface transmission to radio frequency transmitting front end.This method can reduce data transmission and signal processing delay, guarantee the coherence of interference signal, improve the generation accuracy and processing real-time performance of intermediate frequency signal.

The invention discloses a circular grating self-calibration angle measurement method and system based on common aperture bimodal. The method comprises the following steps: synchronously acquiring a heterodyne interference signal from narrow linewidth laser and a low-coherence interference signal from a broadband light source through a common-aperture optical probe; the local scribed line manufacturing error of the inverted circular grating and the installation geometric error of the system are processed respectively; and finally, outputting a calibrated high-precision angle value through an error decoupling and compensation model. The system integrates double light sources, a beam combining and splitting device and a signal processing unit, and realizes synchronous acquisition of angle and morphology information under the same probe. Full error compensation can be completed on line without an external reference, the problem that the scribing error and the installation error are difficult to separate is fundamentally solved, and the precision, the reliability and the environmental adaptability of circular grating angle measurement are remarkably improved.

The invention belongs to the technical field of laser radars, and discloses a low, small and slow single photon radar based on a detection array, which comprises a laser, a beam splitter, an acousto-optic modulator, a light amplification module, a receiving and transmitting light path, a turntable, an optical fiber array, a heterodyne detection array module and a data acquisition and processing module, and the data acquisition and processing module extracts fuselage vibration characteristic parameters of the unmanned aerial vehicle through a vibration characteristic extraction algorithm, and performs unmanned aerial vehicle target identification by using a target identification algorithm. Compared with the prior art, high-coherence laser is generated, large-range airspace laser projection and vibration signal receiving are achieved through the optical fiber array, the heterodyne detection array is combined to suppress environment noise and extract unmanned aerial vehicle fuselage vibration characteristics, and finally accurate detection and recognition of the unmanned aerial vehicle are completed through the signal processing and recognition module. The system has the advantages of being large in view field range, high in anti-interference capability, high in vibration signal extraction precision and the like, and remote, high-sensitivity and low-misjudgment-rate detection of the low-slow-small unmanned aerial vehicle can be achieved.

The present application relates to the field of signal processing, in particular to a kind of signal autonomous detection and classification method based on single vector sensor;The method first utilizes the sound pressure and particle velocity data received by vector sensor to calculate the coherence coefficient of each frequency point and extract phase, obtain phase fluctuation factor by analyzing the statistical characteristics of phase change with time;Then set fluctuation factor threshold, obtain the preliminary detection result of signal using the difference of signal and noise phase fluctuation;Finally, the secondary detection of time length and bandwidth is carried out through the preliminary detection result of signal, and the detection result is classified into narrowband line spectrum signal and wideband signal;Compared with other signal detection techniques based on spectral energy, the present application can provide more robust signal autonomous detection result, and the detection result can be further used for target direction finding and identification.

The application discloses a kind of Φ-OTDR sensing method and system based on composite modulation pulse coding, comprising: obtaining high coherence continuous laser and being divided into probe light and local light;DDS control word of sequence is generated using FPGA to drive DDS to generate two-phase coding sequence and generate linear sawtooth wave voltage to control voltage-controlled oscillator to form linear frequency modulation signal of specified slope;High coherence continuous laser is modulated into two-phase coding light, modulated into composite modulation pulse string twice and signal power amplification is carried out, and is injected into the optical fiber to be measured;Probe pulse is injected into the optical fiber to be measured, backscattering Rayleigh echo is received, and light beat frequency is carried out with local light, and intermediate frequency optical signal is generated and converted into real-time high-speed sampling intermediate frequency electrical signal, signal demodulation, noise reduction and positioning signal processing are carried out.The application breaks through the restriction problem between sensing distance and spatial resolution in traditional distributed optical fiber sensing system, and greatly improves system performance.

The invention relates to the field of rotary mechanical equipment vibration signal processing and rotor fault diagnosis, and provides a rotor rub-impact identification method and system based on cyclic spectrum eigen orthogonal decomposition, and the method comprises the steps: continuously collecting vibration signals of a continuously operating gas turbine and a combined cycle unit support bearing at equal intervals and equal length, and carrying out the preprocessing; a cyclic spectrum correlation mapping graph of the preprocessed vibration signals of the equal-length supporting bearing is obtained, a two-dimensional cyclic spectrum correlation mapping graph is obtained through amplitude normalization, and discrete estimation is carried out; constructing a snapshot matrix and performing intrinsic orthogonal decomposition; and determining the number of reconstructed modes according to the change condition of the modal energy ratio of each order, reconstructing an intrinsic orthogonal decomposition result, carrying out full-band integration along the spectral frequency direction to obtain a fault mode demodulation spectrum, and analyzing the correlation between the fault mode demodulation spectrum and the two-dimensional cyclic spectrum coherence mapping graph to determine the fault occurrence time. According to the method, the fault mode can be accurately extracted, the fault occurrence time can be identified, and the industrial field requirement of unit vibration monitoring in a continuous monitoring scene is met.

The invention belongs to the technical field of electroencephalogram signal processing and brain-computer interfaces, and aims at solving the problems that an existing method is insufficient in task related feature extraction and low in classification precision. The method comprises the following steps: collecting and preprocessing a multi-channel electroencephalogram signal; fusing the phase lock value, the amplitude square coherence and the Pearson's correlation coefficient to construct a multi-modal brain function connection matrix, and constructing a discriminative brain function connection diagram based on a task label; a graph Laplacian operator is used to transform an original signal, a task related mode is enhanced, and redundant information is suppressed; inputting the processed signal into a multi-scale time fusion convolution module, and adaptively extracting deep features of different time scales; and finally realizing classification through a full connection layer. According to the method, an end-to-end classification framework is formed through combination of multi-modal function connection analysis, task oriented graph signal enhancement and multi-scale deep feature learning, the brain cooperation mode is comprehensively captured, and the accuracy and robustness of electroencephalogram mode recognition are remarkably improved.

The present application belongs to the field of wideband phased array radar signal processing and testing technology, and discloses a kind of wideband phased array radar intermediate frequency clutter and interference simulation method, comprising: collecting radar full original physical data, solidification generates static off-line parameter table set;Static routing vector is configured, the intercoupling diffusion rule of establishing damage channel to adjacent element routing is established, while constructing path gating rule and nonlinear trigger rule, form three-domain rule configuration system;Perform geometric path matching processing and channel data stream addressing processing, through sampling point vector coherence superposition and instantaneous power threshold nonlinear distortion injection, generate multi-channel intermediate frequency clutter and interference simulation signal;According to the preset fixed step length adjustment three-domain rule configuration parameter, generate optimization configuration parameter;Intermediate frequency clutter and interference simulation signal is sent to radar receiver through digital-analog conversion, and through effectiveness verification, archive configuration parameter and verification data form reusable data set.

The invention discloses a method and a device for generating and receiving a distributed coherent waveform with variable code element rates, relates to signal processing and distributed coherent technologies, and adopts a waveform synchronization segment and a data segment, and is realized based on a multi-path parallel processing architecture, so that signals of the waveform synchronization segment and the data segment with different code element rates work in the same clock domain; wherein in the waveform synchronization section, a first signal sequence at a first code element rate is adopted, multi-path parallel interpolation is performed after modulation, framing with the data section is waited, and the first code element rate is far greater than a second code element rate of the data section; and the data segment is modulated based on the original data with the second code element rate, then is subjected to multi-time interpolation and multi-phase compensation filtering, and is subjected to digital up-conversion in parallel so as to be framed with the waveform synchronization segment. According to the method, the communication waveforms of the high code element rate synchronization segment and the low code element rate data segment are designed, the requirement for distributed coherent high-precision time synchronization is met, data segment signals are more easily aggregated and enhanced, and the long-distance and anti-interference transmission capacity of the waveforms is improved.

The invention belongs to the technical field of broadband phased array radar signal processing and testing, and discloses a broadband phased array radar intermediate-frequency clutter and interference simulation method, which comprises the following steps: acquiring radar full-amount original physical data, and solidifying to generate a static offline parameter table set; a static routing vector is configured, a mutual coupling diffusion rule of routing from a damaged channel to a neighbor element is established, a path gating rule and a nonlinear triggering rule are constructed at the same time, and a three-domain rule configuration system is formed; geometric path matching processing and channel data flow addressing processing are executed, and multi-channel intermediate frequency clutter and interference analog signals are generated through sampling point vector coherent superposition and instantaneous power threshold nonlinear distortion injection; adjusting the three-domain rule configuration parameters according to a preset fixed step length to generate optimal configuration parameters; the intermediate-frequency clutter and interference analog signals are sent to a radar receiver through digital-to-analog conversion, and a reusable data set is formed through validity verification archiving configuration parameters and verification data.

This invention discloses a real-time piano timbre simulation method and system based on machine learning, relating to the field of audio signal processing technology. The method includes: data acquisition and multi-dimensional annotation, acquiring multiple types of piano audio, covering techniques and seven dynamic levels, and simultaneously acquiring information such as key presses and techniques; audio preprocessing, including pre-emphasis compensation for high frequencies, Hanning window framing, Fourier transform to frequency domain, spectral subtraction for noise reduction and normalization; multi-dimensional feature extraction, extracting static features such as MFCC and spectral parameters, dynamic features such as first- and second-order differences, and overtone structures; two-stage model training, using stacked autoencoders for dimensionality reduction; real-time parsing, filtering and converting acquired performance data into parameter sequences; timbre synthesis, where the model generates a spectrum and performs an inverse Fourier transform into a waveform; and dynamic optimization, receiving user feedback. This invention solves the problems of traditional simulation methods; the two-stage model enhances timbre coherence, dynamic control achieves low latency, and multi-scenario adaptation and feedback optimization meet specific needs.

The application is suitable for the field of radar signal processing, and provides a kind of adaptive ground moving target detection method, including channel equalization processing to multiple groups of echo data received by multiple channels, to obtain multiple groups of equalization data;Channel rearrangement and vectorization processing are carried out on the multiple groups of equalization data to obtain the original matrix;From the original matrix, the rearranged data with data uniformity less than a first preset value and amplitude probability density greater than or equal to a second preset value are selected to obtain multiple groups of screening data;Target detection is carried out according to the multiple groups of screening data to obtain a detection result reflecting whether there is a target;When the detection result reflects the existence of the target, the optimal weight vector is determined using the multiple groups of screening data;The optimal weight vector is used to determine the radial velocity estimate value of the target.The technical scheme based on the application can effectively improve the local non-uniform region coherence, greatly reduce the target false alarm rate, improve the solving efficiency, and effectively improve the target detection performance in the non-uniform strong clutter background.

The invention provides a film thickness measuring device and method based on high-precision frequency domain broadband light interference. The film thickness measuring device comprises a light source (1), an optical fiber coupler (2), a spectral analysis module, a detection arm and a signal processing module used for signal acquisition. Light emitted by the light source is output by the optical fiber coupler, sequentially passes through the collimating lens (3) and the focusing microscope objective (4) at the detection arm and then is divided into two paths at the spectroscope (6); one path of light is reflected to the silicon wafer (5) of the reference arm by the spectroscope and then is reflected back to the spectroscope; the other path of light is reflected back to the spectroscope after transmitting out of the spectroscope to irradiate a sample (7); the two paths of light converge at the spectroscope and interfere with each other, the generated interference light is returned by the optical fiber and then is collected by the spectral analysis module, and the collected data is transmitted to the signal processing module; according to the invention, the resolution of the optical coherent thickness measurement system can be significantly improved, and the application range and potential of the low-coherence interference thickness measurement system can be effectively expanded.

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.

This invention discloses a signal processing method applicable to various signal characteristics, relating to the fields of communication and radar signal processing technology. By combining the construction of a multi-dimensional signal feature library with real-time spectrum sensing, this invention achieves rapid analysis and accurate characterization of deep-space radar signal characteristics. The feature library is generated based on unsupervised clustering of historical data, covering various signal templates such as transient impulses, periodic coherence, and steady-state noise. It not only provides rich prior knowledge references but also supports online sliding window incremental updates, ensuring that feature representation always conforms to actual environmental changes. The real-time spectrum sensing employs adaptive window time-frequency analysis, with the window length dynamically adjusted according to the signal's instantaneous bandwidth and local stationarity, effectively balancing the contradiction between frequency resolution and time resolution and overcoming the limitations of traditional fixed-window analysis in non-stationary scenarios.

The invention provides a height measuring device with anti-interference capability and an anti-interference method thereof, and belongs to the technical field of radar navigation, and the device comprises a modulation parameter agility control module, a modulation source, a transmitter, a transceiving antenna, a frequency mixer and a signal processing and control module. Different modulation parameters are switched in each modulation period through the modulation parameter agility control module, and the transmitter is controlled to generate modulation parameter agility frequency modulation continuous wave signals. The altimeter is in a coherent receiving state and can correctly solve the height; and deception signals intercepted and forwarded by the external jammer lose coherence due to parameter mismatch, and are filtered or suppressed by the system. According to the invention, the action mechanism of deception interference is destroyed, the anti-interference capability and reliability of the radio altimeter in a complex electromagnetic environment are effectively improved, and meanwhile, the compatibility with the working frequency band of a traditional system is kept.

The invention discloses a nondestructive quantitative detection method and system for the bonding quality of a tunnel surrounding rock-lining concrete interface, particularly relates to the technical field of nondestructive detection based on MEMS ultrasonic sensors, and aims to solve the problem that the evaluation accuracy of the bonding quality of the interface is influenced by signal aliasing caused by ultrasonic mode conversion in the conventional method. An MEMS ultrasonic sensor array is used for transmitting ultrasonic pulses in a preset frequency range to a tunnel surrounding rock-lining concrete interface and receiving reflected or transmitted echo signals, and digital signal processing is carried out on the echo signals to calculate spectrum coherence and envelope variance so as to detect the signal aliasing phenomenon. When aliasing is detected, longitudinal wave and transverse wave components are separated, sound velocity variation and attenuation coefficients are extracted as characteristic parameters, and a bonding uniformity grade and a defect distribution mode are identified in combination with a pre-calibrated interface bonding state classification model; and finally, according to an identification result, carrying out regression analysis on an incidence relation between the shear wave attenuation coefficient and the interface bonding strength, and correcting to generate a quantitative evaluation value.

The invention discloses a piano tone real-time simulation method and system based on machine learning, and relates to the technical field of audio signal processing, and the method comprises the steps: data collection and multi-dimensional marking, collection of multiple types of piano audios, skill coverage and seven levels of strength, and synchronous collection of information such as keys and skill; performing audio preprocessing, pre-emphasis high frequency compensation, Hanning window framing, Fourier transform to frequency domain, spectral subtraction denoising and normalization; multi-dimensional feature extraction: extracting static features such as MFCC and spectrum parameters, dynamic features such as first-order and second-order differences and an overtone structure; carrying out two-stage model training, and carrying out stacking auto-encoder dimensionality reduction; analyzing and acquiring playing data in real time, filtering and converting into a parameter sequence; synthesizing timbre, generating a frequency spectrum by a model, and performing inverse Fourier transform to form a waveform; and dynamically optimizing and receiving user scores. According to the invention, the traditional simulation problem is solved; the dual-stage model enhances tone coherence, and dynamic control realizes low delay, multi-scene adaptation and feedback optimization fitting requirements.