23 results about "Doppler effect" patented technology

This invention relates to a method and system for locating coaxial counter-rotating sound sources in rotorcraft, belonging to the technical field of sound source identification methods. It includes: processing the sound pressure signal of the moving sound source using continuous wavelet transform to obtain time-frequency domain variation results; performing Doppler effect correction based on experimental conditions; estimating the spatial location and relative intensity of the noise source using a cross-spectral matrix and weight vector; and performing phase-locked analysis of the rotor noise source intensity using a phase-locked averaging method. This invention differs from traditional time-domain delay superposition algorithms and frequency-domain cross-correlation spectrum methods. It can image unsteady sound sources using time-frequency domain characteristics, solving the acoustic imaging problem of counter-rotating propeller noise and possessing potential applications in the rotorcraft industry.

The application discloses a detonation test method and device based on laser technology in the technical field of detonation experiment test, S1, detonation ignition, makes the flyer pass through the first observation point, the second observation point and the third observation point in turn; S2, laser Doppler effect monitoring, wavelength change data when the laser beam irradiates the flyer is acquired through the end laser interferometer; then the first observation point, the second observation point and the third observation point respectively emit positioning laser beams to carry out again Doppler effect monitoring on the passing flyer, positioning wavelength change data is obtained; S3, the time when the flyer passes through each observation point is determined, the corresponding flying time and passing time of the flyer under the first observation point, the second observation point and the third observation point are obtained based on the wavelength change data and the positioning wavelength change data; then the passing time is corrected based on the flying time; so as to eliminate the cumulative error, make the obtained experimental data more accurate, and facilitate the accurate prediction of the speed of the flyer.

This invention specifically relates to a method for correcting the critical boron concentration under full power conditions. Based on a three-dimensional reactive equilibrium equation and considering the influence of temperature deviation on the Doppler effect, the critical boron concentration under full power conditions is: where CB ref This represents the critical boron concentration at full power; CB m ρ represents the actual boron concentration under the measured conditions. xem Indicates the equilibrium xenon poisoning under measurement conditions; ρ xeref This represents the balanced xenon poisoning at full power; ρ rccam Indicates the reactivity introduced by the control rod under measurement conditions; pr m Indicates the actual power under the measured conditions; HFP represents full power; α pc α represents the average of the sum of the power coefficients under the measured state and the full-power state; b T represents the average of the sum of the differential boron values ​​under the measured state and the full-power state; avgm T represents the average temperature of the moderator under the measured conditions. ref (pr m ) represents the moderator reference temperature under measurement conditions; α ttcm This represents the total temperature coefficient under the measurement conditions. The invention also relates to computer equipment and a computer-readable storage medium, outlining the steps for implementing the above-described method for correcting the critical boron concentration under full power conditions. Based on a three-dimensional reactive equilibrium equation, and considering the influence of temperature deviation on the Doppler effect, this invention achieves accurate correction of the critical boron concentration under full power conditions when nuclear power units increasingly participate in peak shaving.

A frequency shifting device based on the Doppler effect, a noise bypass frequency shifting device based on the receiver, a composite noise reduction device, and a method are disclosed. The frequency shifting device based on the Doppler effect includes: a rotor module (101) with a noise port, the noise port including a first noise port (10101) and a second noise port (10102). The first noise port (10101) is connected to the second noise port (10102) on the noise propagation path. The first noise port (10101) is used to connect to a sound source or output frequency-shifted noise. The second noise port (10102) follows the rotor module (101) in a periodic motion relative to a reference frame, causing a Doppler effect due to the relative motion between the second noise port (10102) and the noise source. This results in a frequency shift in the transmission or reception frequency relative to the reference frame. The frequency shift of the second noise port (10102) relative to the reference frame is controlled by changing the speed of the periodic motion. The reference frame includes an inertial reference frame and a non-inertial reference frame. This invention addresses the technical deficiency of existing general-purpose silencer technology, which suffers from the invariability of silencing characteristics due to limitations in material properties or structural design. It realizes a new type of silencer with variable silencing characteristics, namely, a frequency shifting device, silencing equipment, and method based on the Doppler effect.

The invention provides a marine vibroseis synchronous correction and signal separation method and device. The marine vibroseis synchronous correction and signal separation method comprises the steps of obtaining an original seismic record, obtaining an actual measurement aliasing common detection point gather, and minimizing a predetermined objective function by embedding a prior model into an inversion iteration process in a plug-and-play mode to unmix and correct the actual measurement aliasing common detection point gather, obtaining available single-source seismic data; wherein the priori model comprises a plurality of denoising devices, each denoising device adopts a CNN structure, and the priori model is obtained by training a simulation aliasing common detection point gather obtained through forward modeling and a simulation single-source common detection point gather corresponding to the simulation aliasing common detection point gather through pseudo seismic data obtained through conversion of a natural image data set and pseudo seismic data with noise corresponding to the pseudo seismic data. According to the invention, the Doppler effect caused by ship motion can be effectively eliminated, the problem of aliasing of seismic data acquired by multiple seismic sources is solved, and the reliability and generalization ability of marine seismic data processing are improved.

The application provides a method and system for detecting radial velocity of a flow field, and the system for detecting radial velocity of a flow field is used to generate a common Gaussian light beam and a high-order vortex light beam with a non-zero radial coefficient; the high-order vortex light beam is used to irradiate a measured fluid and pass through the measured fluid to generate target detection light carrying radial information of the fluid, and the common Gaussian light is interfered with the target detection light to generate a heterodyne interference signal; a detector is used to detect the heterodyne interference signal and analyze a Doppler spectrum; and the radial velocity of the measured fluid is determined according to the Doppler spectrum. When the detection light irradiates the measured fluid, fluid particles in the measured fluid move radially in a light spot of a high-order vortex light beam orthographic projection, the application uses the high-order vortex light with an intensity distribution in the radial direction to detect the flow field to generate a Doppler effect, so that the radial velocity of the flow field is detected, and therefore the application has a wide application scenario.

This invention relates to the field of underwater acoustic signal processing technology, and in particular to a method for enhancing the line spectrum of moving targets based on an elite selection genetic algorithm. Based on the Doppler-warping transform, the method utilizes an elite selection genetic algorithm to autonomously optimize and estimate the target's motion parameters. Using the entropy of the transformed target signal's spectral function as the cost function, the optimal motion parameters are searched by comparing the spectral entropy values ​​under different parameters. Then, the optimal parameters are used to perform a Doppler-warping transform on the original signal, refocusing the line spectrum energy dispersed by the Doppler effect near the original frequency, thus achieving autonomous enhancement of the moving target's line spectrum. This invention effectively solves the problems of the inability to accumulate moving target line spectrum energy over long periods and the autonomous search of Doppler-warping transform parameters, improving the probability and accuracy of line spectrum detection. It can be applied to data backtracking and review processing in underwater moving target detection, and has good engineering practical value.

The application provides a squint radar linear frequency modulation signal distance space variation Doppler correction method, which comprises the following steps: obtaining a time delay correction value Δτ(τ) corresponding to each distance unit relative to a scene center according to a Doppler center f d (R i ) of each distance unit i ); performing linear fitting to obtain a linear fitting first-order term coefficient α and a constant term β; performing distance linear space variation time delay correction; obtaining a distance space variation Doppler correction signal and performing distance compression to obtain a distance space variation Doppler correction distance compression result The application provides a distance space variation Doppler effect compensation strategy, which eliminates target distance positioning errors caused by squint observation.

The application discloses a radar communication integrated signal optimization method and belongs to the technical field of radar communication integration. The application constructs a multi-pulse OFDM integrated signal model, designs an ICI self-cancellation precoding matrix based on frequency offset and Doppler effect, and suppresses inter-subcarrier interference; meanwhile, an inter-pulse coherent communication sequence is designed by combining Gold sequences and coherent accumulation constraints, so that the multi-pulse phase coherence is ensured. The transmitting end loads the precoded communication information to OFDM subcarriers to generate an integrated signal; the receiving end first performs ICI compensation and coherent accumulation, and then completes detection and demodulation. The application can significantly reduce waveform sidelobes, improve ranging and speed measurement accuracy and weak target detection performance, is compatible with a traditional OFDM structure, and is suitable for high-speed motion scenes such as vehicle-mounted radars and airborne detection.

The application discloses a frequency offset determination method and device of a signal, electronic equipment and a computer program product. The method comprises the following steps: using a preset detection window to detect the signal power of a physical random access channel signal, wherein the physical random access channel signal is represented according to the Zadoff-Chu sequence; determining the maximum peak power and two secondary peak powers of the physical random access channel signal based on the preset detection window; determining the peak power ratio of the maximum peak power and the maximum secondary peak power; and analyzing the two secondary peak powers and the peak power ratio based on a preset rule to determine the frequency offset information of the physical random access channel signal. The application solves the technical problem that, in a non-terrestrial network (NTN) scene, due to the relatively serious Doppler effect, the frequency offset is relatively large, and the conventional frequency offset estimation method is not applicable.

The application provides an AGV communication channel modeling method and system based on an ellipsoid geometry random model, and belongs to the technical field of wireless communication channel modeling; the method comprises the following steps: a three-dimensional digital scene covering multiple frequency bands, AGV speeds and container densities is constructed, and a multi-dimensional channel data set is constructed based on ray tracing; a dynamic ellipsoid geometry model with a fixed base station and an AGV as the focus is constructed, and a time-varying characteristic is introduced by updating the AGV position in real time; the communication channel is divided into three parts, namely, a line-of-sight part, a ground reflection part and a non-line-of-sight part, the channel complex gains of the three parts are respectively modeled, and are superimposed to synthesize the channel impulse response under the FR3 frequency band. Through the introduction of the speed-dependent Doppler effect and the density-dependent metal scattering mechanism, the time-varying non-stationary characteristics of the AGV channel in the metal dense scene of the port can be accurately described, and efficient and accurate theoretical model support is provided for the intelligent port AGV communication design.

The present disclosure provides a marine controllable source synchronous correction and signal separation method and device. The marine controllable source synchronous correction and signal separation method of the present disclosure comprises: obtaining an original seismic record to obtain a measured aliasing common receiver gather, minimizing a predetermined objective function by embedding an a priori model into an inversion iteration process in a plug-and-play manner to demix and correct the measured aliasing common receiver gather to obtain usable single-source seismic data; wherein the a priori model comprises a plurality of denoising devices, each denoising device adopts a CNN structure, and the a priori model is trained by a simulated aliasing common receiver gather and its corresponding simulated single-source common receiver gather obtained by forward simulation, pseudo seismic data converted from a natural image data set and its corresponding noisy pseudo seismic data. The present disclosure can effectively eliminate the Doppler effect caused by ship motion, solve the aliasing problem of multi-source acquisition seismic data, and at the same time improve the reliability and generalization ability of marine seismic data processing.

The application discloses an ultranarrow-bandwidth atomic filter based on cold atoms and an implementation method thereof. The application combines cold atoms with an atomic filter, slows down atoms through laser cooling technology, reduces the influence of Doppler effect, and further realizes an ultranarrow-bandwidth atomic filter with a transmission bandwidth close to the natural line width of atomic transition. The implementation of the application can solve the problem that the influence of thermal atomic Doppler broadening causes the transmission bandwidth to be unable to be further narrowed in the existing transmission bandwidth narrowing technology of a Faraday atomic filter, and can expand the research of a traditional thermal atomic Faraday filter to the field of cold atoms in modern science, provide new possibilities for substantial and significant progress and construction of a filter based on cold atoms, and bring extremely potential development to many fields. The application overcomes the limitation of thermal atomic Doppler broadening on the further narrowing of the transmission bandwidth of a Faraday atomic filter, and brings a significant bandwidth narrowing effect.

The application provides a blind area target danger level evaluation method and system based on Doppler phase frequency characteristics, and relates to the technical field of vehicle blind area monitoring.The method comprises the following steps: radiating a linear frequency modulation continuous wave signal to a vehicle blind area, capturing a coherent echo scattered by a target, and performing mixing filtering and analog-digital sampling processing to obtain a complex baseband signal sequence; based on the complex baseband signal sequence, analyzing gradient information of phase changes of the complex baseband signal and a coupling relationship with a Doppler effect, and constructing Doppler phase frequency characteristic data; based on the Doppler phase frequency characteristic data, selecting three physical aperture centers in a radar receiving antenna array as spatial sampling nodes; constructing a three-dimensional dynamic Doppler potential field surface through phase differences between the spatial sampling nodes; and performing an isosurface topological segmentation on the three-dimensional dynamic Doppler potential field surface to extract a discrete scattering point set.The application realizes accurate estimation of a blind area target motion state and scientific determination of a danger level.

The application discloses a kind of multi-carrier underwater acoustic communication channel estimation methods under time delay-scale double expansion, for general multi-carrier underwater acoustic channel model, the influence of insufficient characterization of Doppler effect, and the precision of traditional channel estimation method is limited, it is proposed to utilize time delay-scale double expansion channel model to characterize the influence of Doppler effect on multi-carrier underwater acoustic communication system, and utilize orthogonal matching pursuit algorithm to separate multipath signal, and the delay and size parameter estimation results of each path of channel are corrected using Newton method, while realizing off-grid channel estimation, reduce algorithm complexity.The characterization of the present application to Doppler effect is more in line with the real scene, and realizes off-grid channel estimation and low complexity algorithm, so that the channel estimation result is more accurate.

This invention relates to a rate optimization method for IRS-NOMA systems in high-speed mobile scenarios, belonging to the field of wireless communication technology. The method includes: establishing a high-speed mobile IRS-NOMA system model incorporating the Doppler effect; constructing a trajectory prediction model based on historical location information to predict future locations; optimizing the IRS phase configuration matrix based on the predicted locations, with the objectives of maximizing the signal-to-noise ratio, minimizing Doppler spread, and minimizing control delay spread; jointly constructing an optimization problem with IRS phase shift optimization and NOMA user power allocation, aiming to maximize the system weighted sum rate, and solving it through an alternating optimization method; and employing block optimization, incremental updates, and pre-computation low-complexity strategies to achieve real-time processing. This invention guides forward optimization through trajectory prediction and utilizes the IRS to actively suppress the Doppler effect, achieving deep collaboration between IRS and NOMA in high-speed mobile scenarios. This effectively improves system throughput, user fairness, and communication reliability, while meeting the real-time computation requirements of high-speed scenarios.

The application discloses a cold atom frequency stabilization laser and an implementation method thereof, and belongs to the technical field of lasers. In order to solve the problems of large cavity length thermal noise in laser frequency stabilization based on an optical resonant cavity and Doppler broadening and collision broadening in frequency stabilization based on an atomic and molecular gas chamber, the application uses a cold atom recoil resonance spectrum as a frequency reference source, constructs a closed-loop frequency stabilization system including an optical detection link and an electrical feedback control link, and realizes accurate modulation and stable control of laser output frequency. The application can effectively inhibit the influence of Doppler effect and collision effect on frequency stabilization accuracy, and improve laser frequency stability and long-term operation reliability.

This invention discloses an existence detection device and a method for defining its detection range. The existence detection device includes an infrared detection module, a microwave detection module, and at least one blind zone defining medium. The infrared detection module detects the presence of a human body in a target detection area based on a Fresnel lens. The microwave detection module detects the presence of a human body using microwaves based on the Doppler effect. The detection area formed by the infrared detection module in the target detection area is the infrared detection area of ​​the infrared detection module, and the target detection area outside the infrared detection area is the infrared detection blind zone of the infrared detection module. The blind zone defining medium is disposed at the detection field of view of the infrared detection module to define the detection blind zone of the infrared detection module in the target detection area, thereby defining the infrared detection area.

The application provides a kind of underwater acoustic signal Doppler estimation method based on improved firefly algorithm, adopts pseudo-random sequence to construct transmitting signal, improves signal in mobile underwater acoustic communication scene anti-multipath interference, broadband Doppler effect ability;At receiving end, first, through larger step size, Doppler is roughly estimated, in the narrowed Doppler factor search range, based on variable scale chaos strategy, improved firefly algorithm is used, the correlation of received signal and local reference signal carrying different Doppler factors is used to construct objective function, the fitness value is calculated, the Doppler estimation is converted into continuous optimization problem, with lower calculation complexity, the Doppler estimation precision meeting the synchronization demand of underwater acoustic communication is obtained, and the estimation stability in larger Doppler range is guaranteed by using the Doppler sensitive property of the method.

This invention discloses a multi-source localization method for vehicle-mounted microphone arrays based on Doppler effect compensation. First, a mobile received signal model is established to analyze the amplitude-frequency modulation characteristics caused by relative motion, and a compensation algorithm combining nonlinear time mapping and amplitude correction is proposed. Doppler distortion is eliminated through time-domain inverse resampling. Second, addressing the nonlinear coupling problem between compensation and position calculation, a closed-loop localization model based on a "hypothesis-compensation-verification" mechanism is constructed. Furthermore, a ring-topology niche particle swarm optimization algorithm is introduced to achieve multi-peak parallel detection, overcoming the shortcomings of traditional algorithms that easily get trapped in local optima; simultaneously, a density clustering algorithm is combined to remove noise points, achieving automatic extraction of multi-source coordinates. This method effectively overcomes Doppler distortion and multi-source aliasing interference, significantly improving the localization accuracy and robustness in dynamic environments. Real-vehicle experiments show that the dual-source localization error is controlled within 0.45 meters.

This application relates to a method and system for monitoring unmanned aerial vehicles (UAVs) based on the Doppler effect of a seismograph. The method includes: acquiring ground vibration signals of the monitoring area collected by a seismograph, segmenting them, and then performing detrending, denoising, and filtering processing; performing time-frequency analysis on the processed vibration signals to obtain the corresponding time spectrum; extracting UAV signals from the time spectrum using an artificial intelligence algorithm and inputting them into a pre-trained deep learning model to output the time-frequency trajectory region of the UAV signals and their corresponding time range; performing dominant frequency tracking within the time-frequency trajectory region to obtain the instantaneous frequency sequence that changes with time, and extracting frequency offset information representing the Doppler effect of relative motion; constructing Doppler inversion constraints based on the frequency offset information, and obtaining estimation results of the UAV excitation frequency, flight speed, flight altitude, and spatial position through optimization; performing trajectory consistency constraints and anomaly removal on the estimation results, outputting the UAV monitoring results, and generating a monitoring report.