1349 results about "Frequency shift" patented technology

The invention provides a tunnel deformation parameter inversion method and device based on distributed optical fibers, and relates to the technical field of tunnel deformation parameter inversion, and the method specifically comprises the steps: selecting a monitoring point in a tunnel, arranging an optical fiber sensor, and obtaining a Brillouin scattering signal generated by the optical fiber sensor under the stress effect of the corresponding monitoring point; extracting a Brillouin frequency shift corresponding to the monitoring point, and determining an environmental effect frequency shift correction value by using the temperature change data, the humidity change data and the service time of the optical fiber sensor; determining the structural strain of the monitoring point according to the Brillouin frequency shift and the environmental effect frequency shift correction value, generating a three-dimensional strain field cloud picture, performing spatial registration on the three-dimensional strain field cloud picture and the geometric topology of the model, and performing three-dimensional grid division; the structure strain of the monitoring point is mapped to the grid node at the corresponding position, the structure strain of other grid nodes is determined based on the space distance attenuation law, inversion of the whole tunnel deformation parameters is completed, and the tunnel deformation monitoring precision and efficiency are improved.

The invention relates to the technical field of unmanned aerial vehicle autonomous decision, provides an unmanned aerial vehicle autonomous decision reinforcement learning method, system and device based on multi-objective optimization, and a storage medium, and solves the problems of limited dynamic task distribution capability and poor decision capability of an unmanned aerial vehicle. The method comprises the steps that based on infrared data and radar data, a moving track prediction sequence of a suspicious target in a target area is generated, a moving probability thermodynamic diagram is constructed, and the target area comprises a patrolled area; performing Doppler frequency shift analysis on the radar data to generate a target velocity vector field; and in combination with the position data of the unmanned aerial vehicle, outputting an unmanned aerial vehicle autonomous decision reinforcement learning result of a dynamic segmentation scheme containing an unpatrolled region through a region re-division reinforcement learning model based on a reward function for multi-objective optimization. The reward function is used for reflecting area coverage rate maximization, target tracking success probability maximization and path energy consumption minimization. According to the invention, autonomous intelligent decision-making of the unmanned aerial vehicle on the unpatrolled area is realized.

The invention discloses a laser radar test method based on a long-distance target distance measurement result, and the method comprises the following steps: obtaining a laser radar echo signal, and extracting the frequency spectrum information of the echo signal; doppler frequency shift characteristic parameters are extracted according to the frequency spectrum information, and the relative speed of the target is calculated based on a preset frequency shift calculation model; acquiring multi-source sensor data associated with the laser radar test platform, and fusing to construct a dynamic ranging reference coordinate system; performing dynamic motion compensation on a laser ranging result according to the relative speed of the target to obtain a target initial measurement distance after Doppler correction; mapping the target initial measurement distance after Doppler correction to the dynamic distance measurement reference coordinate system to obtain a remote target final distance measurement result aligned with a test platform coordinate system; and outputting the accurate position and moving state information of the target in the three-dimensional space according to the final distance measurement result. According to the invention, the ranging precision and stability can be improved.

The invention relates to the technical field of deformation monitoring, in particular to a mountain tunnel surrounding rock deformation monitoring method and system based on distributed optical fiber sensing. The method comprises the following steps that Brillouin frequency shift original data and center wavelength original data are collected, tunnel construction progress data and surrounding rock geological survey data are obtained at the same time, format standardization and time sequence alignment processing is carried out, and preprocessed optical fiber sensing basic data, construction time sequence data and geological attribute data are generated; surrounding rock deformation characteristic parameters are extracted based on the optical fiber sensing basic data, and surrounding rock deformation multi-dimensional characteristic vectors are constructed; performing deformation mode density clustering and surrounding rock deformation dynamic prediction based on the surrounding rock deformation multi-dimensional feature vector to generate a surrounding rock deformation dynamic prediction value; and carrying out comparison and iterative correction on the dynamic prediction values of the surrounding rock deformation, and carrying out regionalized polymerization to generate a mountain tunnel surrounding rock deformation spatial and temporal distribution visualization result. According to the invention, full-time-space accurate monitoring and early warning of tunnel surrounding rock deformation can be realized.

The invention provides a tunnel deformation monitoring system and method based on a distributed optical fiber sensing technology, and relates to the technical field of tunnel monitoring. A spiral winding type optical fiber is arranged in the longitudinal axis direction of the surface of a tunnel lining, a transverse optical fiber is arranged on a key section, and the data acquisition frequency is set to be 1Hz. Dividing the optical fiber into a plurality of data acquisition points at equal intervals, obtaining the real-time temperature and Brillouin frequency shift change of each point, measuring the temperature and strain sensitivity coefficient, and calculating the total strain; calculating long-term temperature strain compensation based on the long-term temperature component, generating an instantaneous temperature difference through the real-time temperature and the long-term temperature component, further calculating instantaneous temperature strain compensation, subtracting the two kinds of strain compensation from the total strain to obtain stress strain, and evaluating the deformation level of the tunnel based on the stress strain. And the accuracy of evaluation is judged through clustering analysis.

The invention relates to the technical field of structural stress precision measurement, in particular to a distributed optical fiber sensing-based steel structure stress monitoring method, which comprises the following steps of: 1, constructing a sensing optical fiber array in a steel structure node area; 2, injecting optical pulses into the sensing optical fiber array, and synchronously collecting Brillouin frequency shift signals and Raman scattering signals of all points; 3, temperature and mechanical strain are separated based on the reference optical fiber signals, global temperature compensation is adopted for the first optical fiber set, and temperature gradient compensation along the optical fiber path is adopted for the second optical fiber set; 4, decomposing the compensated mechanical strain into multidirectional strain components according to the spatial orientation of the optical fiber, and reconstructing a three-dimensional stress field through strain component fusion; and 5, dynamically judging the damage risk according to the local stress concentration coefficient and the change rate thereof in the stress field. And through the temperature compensation technology, the influence of the environment temperature change on the strain data is eliminated, and the reliability of the monitoring result is improved.

The invention discloses a fringe projection three-dimensional shape measurement method based on frequency domain and time domain joint coding, and the method comprises the following steps: firstly, embedding a multi-frequency three-step phase shift fringe pattern in the vertical direction based on multi-scale region division, introducing four-step phase shift and complementary Gray code joint coding in the horizontal direction, generating a coding pattern set, and carrying out the projection; after an image is collected, frequency domain transformation and time domain decoding are carried out respectively, and a vertical dominant frequency position, a horizontal period number and a wrapped phase are obtained; then, combining a main frequency position in the vertical direction with a period number and a wrapped phase in the horizontal direction, and extracting a space coordinate of a direct illumination component based on frequency position invariance; and finally, establishing a pixel homonymy point mapping relation between the projector and the camera, and realizing high-precision three-dimensional reconstruction. Compared with a traditional frequency shift method, the method has the advantages that projection patterns are greatly reduced, reconstruction precision and anti-interference performance are improved, and the method is suitable for dynamic three-dimensional measurement under complex illumination conditions such as specular reflection, semitransparent shielding and subsurface scattering.

The invention discloses an optical cable icing galloping online monitoring system based on a BOTDR, and belongs to the technical field of distributed optical fiber sensing. The system comprises an optical module, a signal processing module and a data processing module, the optical module is used for generating a detection light signal and interacting with a sensing optical fiber to obtain a Brillouin scattering signal, and then the Brillouin scattering signal is converted into an electric signal; the signal processing module is used for performing frequency down-conversion, signal filtering and digital acquisition on the electric signal to obtain multiple groups of Brillouin scattering signal data; the data processing module is used for processing the multiple groups of Brillouin scattering signal data and extracting a Brillouin frequency shift center frequency; temperature and strain distribution along the optical cable is obtained according to the frequency shift, and temperature and strain states are transmitted to a QT upper computer through PCIE for real-time display. According to the invention, high-precision and long-distance optical cable icing galloping monitoring can be realized, reliable early warning and safety guarantee are provided, and technical support is provided for maintenance and management of an electric power system.

The invention discloses a joint estimation method for timing advance and frequency offset based on a conjugate symmetric ZC sequence, which relates to the technical field of wireless communication and comprises the following steps of: inputting a leader sequence extracted from a demodulated received signal; two ZC sequences in the leader sequence are respectively in cross-correlation with a local ZC sequence, and a peak value of a cross-correlation result amplitude is obtained; iteratively performing fractional frequency offset compensation estimation to obtain a fractional frequency offset estimation value and a compensated leader sequence; performing timing advance estimation and integer frequency offset estimation to obtain a timing advance estimator and an integer frequency offset estimator; obtaining a frequency offset estimation value by combining the decimal multiple and integer multiple frequency offset estimation values; and ending the timing advance and frequency offset estimation, and outputting estimated values of the timing advance and the frequency offset. According to the method, the negative influence of the decimal frequency offset on the ZC sequence is eliminated in a mode of iteratively compensating and estimating the decimal frequency offset, and high-performance timing advance and frequency offset joint estimation with robustness to frequency shift and noise is realized based on the structure of the conjugate symmetric ZC sequence; the method is suitable for a non-ground network communication scene with large Doppler frequency shift and low receiving signal-to-noise ratio.

The invention discloses an intelligent control method and system for a motor driver, and the method comprises the steps: building an acoustoelectric incidence matrix through collecting harmonic current and sound pressure fluctuation data in the operation process of a motor, and forming a fault feature library; identifying an available fault mode to determine an energy collection point, and performing phase deviation processing on the collection point to generate an auxiliary driving signal; performing spectrum analysis on the sound pressure fluctuation data to obtain an acoustic characteristic spectrum, extracting an efficiency indication tone through characteristic decomposition, mapping the efficiency indication tone into a torque optimization parameter, and establishing a noise reduction control table; performing spectrum analysis on the enhanced control domain to identify a high-energy frequency band, executing a frequency shift operation to generate a safety frequency band signal, and forming a multi-frequency band management strategy in combination with a noise reduction control table; a management strategy is decomposed into parallel control flows for sequential staggered arrangement, and an energy-saving control matrix is generated; and generating a PWM control signal based on the matrix, carrying out edge reconstruction, and obtaining a softened edge waveform through an anti-resonance injection technology to complete intelligent control of the motor driver.

The invention discloses an SAR sea surface flow velocity inversion method based on physical guidance and data driving fusion, and relates to the field of flow velocity inversion, and the method comprises the steps: carrying out the non-geophysical Doppler frequency shift correction of the Doppler frequency shift observed by a spaceborne synthetic aperture radar, and obtaining the geophysical Doppler frequency shift; predicting based on a wave-induced Doppler frequency shift model according to a radar incident angle, reanalyzed wind direction data, a sea surface 10-meter height wind speed inverted by an SAR (Synthetic Aperture Radar), a simulated wind wave parameter, a simulated surge parameter and a simulated maximum wave parameter to obtain a wave-induced Doppler frequency shift; the wave-induced Doppler frequency shift model is obtained based on physical guidance and data-driven modeling; doppler frequency shift generated by sea surface flow is determined according to the geophysical Doppler frequency shift and the wave-induced Doppler frequency shift; according to the method, the Doppler frequency shift generated based on the sea surface flow is converted to obtain the sea surface radial flow velocity, the wave-induced Doppler frequency shift is accurately removed, and reliable inversion of the sea surface flow velocity is realized.

The invention relates to the technical field of satellite communication signal processing, and discloses a broadband satellite signal blind demodulation reconstruction method and system based on sparse representation. The method comprises the following steps: carrying out frequency domain transformation on broadband satellite mixed signals to extract pilot frequency features to construct a beam state feature matrix, inputting the matrix into an adversarial network to generate a beam adaptive sparse dictionary, constructing a topological relation graph according to a Doppler frequency shift set, and carrying out collaborative sparse decomposition to obtain a sparse coefficient matrix; and extracting a code rate candidate set to execute parallel sparse reconstruction, determining an actual code rate through self-consistency verification to obtain a complete signal, analyzing a switching instruction, extracting time sequence statistical characteristics, predicting target domain characteristics, generating a switched sparse dictionary, and executing demodulation. The sparse decomposition precision, the code rate blind estimation accuracy, the cooperative processing efficiency and the switching continuity of the broadband satellite mixed signals are improved.

The invention relates to the technical field of wireless communication, in particular to a multimode chip core architecture system realized based on a software radio technology, which comprises an anti-interference module used for executing real-time optimization on a multi-system compatible baseband data stream and calling a dynamic compensation mechanism based on dynamic frequency shift characteristics in an environment characteristic data set, adjusting a local frequency source and a channel equalization parameter through multi-stage compensation operation to obtain an anti-interference enhanced data stream; and the packaging module is used for packaging the anti-interference enhanced data stream and the positioning data into a time-hopping pulse-direct sequence code division multiple access fusion frame structure and sending the fusion frame structure through a radio frequency unit. Through an ASIC and SDR hybrid architecture and a four-level hierarchical design, a multi-system communication function is integrated, and the hardware efficiency is improved and the power consumption is reduced.

The invention provides an intelligent optical cable performance prediction method and system for a data center, and relates to the technical field of data center performance analys.The intelligent optical cable performance prediction method comprises the steps that firstly, an optical cable microstructure disturbance quantization model is constructed, and an optical cable is divided into a plurality of virtual quantization units in the longitudinal direction; each unit packages a real-time stress-strain state parameter and a response sensitivity coefficient of the basic structure unit, inputting a Brillouin scattering spectrum frequency shift data flow collected in real time into the model for disturbance source analysis, generating a physical excitation decomposition sequence, driving a virtual quantization unit to perform state evolution iterative operation according to the physical excitation decomposition sequence, and obtaining a Brillouin scattering spectrum frequency shift data flow model; a stress-strain state evolution track set is obtained, a time-space correlation network of optical cable link disturbance propagation is constructed according to the stress-strain state evolution track set, network flow characteristic analysis is conducted on the time-space correlation network, an early warning node set is extracted, the future evolution trend of the early warning node set is calculated, and serialized optical cable performance abnormity early warning information is generated. The optical cable performance abnormity can be predicted in advance, and stable operation of the data center optical cable is guaranteed.

The invention provides a distributed optical fiber sensing system based on AOM frequency shift and a vibration positioning method, and relates to the technical field of optical fiber sensing, probe light emitted by a light source is divided into two branch light beams, one branch light beam is input into a first interferometer structure after frequency shift, and the other branch light beam is input into a second interferometer structure. The two split light beams are coupled in the interferometer structure to obtain sensing light and reference light, and the sensing light is coupled with the reference light in the light demodulation element after passing through the sensing optical fiber to obtain interference light. The two paths of interference light are converted into electric signals, then the signal processing assembly is used for eliminating Rayleigh backscattering noise signals, and the vibration position in the sensing optical fiber is determined according to the phase delay inequality between the two electric signals. According to the invention, the interference of Rayleigh backscattering is avoided, the sensing distance is increased, the signal-to-noise ratio of the system is improved, an additional light source is not needed, only a single optical fiber is used for transmission, and the cost is reduced.

The invention relates to the field of ocean current remote sensing, and relates to a vector flow inversion method combining a single-station ground wave radar and a satellite-borne SAR, and the method mainly comprises the steps: calculating the frequency deviation of a first-order Bragg peak of the ground wave radar, carrying out the inversion of the sea surface radial flow of the ground wave radar, and carrying out the inversion of the sea surface radial flow of the SAR through employing a Doppler centroid anomaly method; interpolating a ground wave radar radial flow result to an SAR data grid through bilinear interpolation; inverting a single-station vector flow based on a ground wave radar radial flow result, projecting single-station vector flow data with high confidence coefficient to an SAR range direction, calculating a difference mean value of a projection flow velocity and an SAR radial flow velocity, and further calibrating the SAR radial flow; and combining a ground wave radar radial flow result with the calibrated SAR radial flow to invert a vector flow. According to the method, the defect of ocean current observation through a single means is overcome, high-precision inversion of the combined vector flow is achieved, and the method has important significance on ocean environment monitoring, disaster forecasting, shipping safety and the like.

The invention belongs to the technical field of road engineering detection, and discloses a geological radar and distributed optical fiber roadbed compaction detection method and device, and the method comprises the steps: obtaining a dielectric constant profile detected by a radar and the initial Brillouin scattering light frequency offset of optical fiber strain; establishing an initial reference state including optical fiber strain distribution and a radar dielectric constant profile; comparing the Brillouin scattering light frequency offset and the radar dielectric constant profile image which are acquired in real time with an initial reference state, determining a strain gradient abrupt change region, and correcting a preset optical fiber temperature drift compensation model by using a radar scanning result; and performing temperature drift component removal on the Brillouin scattering light frequency offset obtained in real time to obtain pure strain frequency shift data, calculating according to the frequency shift data to obtain accumulative settlement, and generating a roadbed compaction effect detection result. Continuous longitudinal strain monitoring is provided through the geological radar and the sensing optical fiber, and an abnormal section is accurately positioned.

The invention relates to the technical field of communication, and discloses a network communication chip signal interference suppression processing method. The method comprises the following steps: acquiring a local oscillator phase jitter sequence in real time through an on-chip phase noise monitoring unit; estimating Doppler frequency shift and channel coherence time based on the sequence; dynamically adjusting the closed-loop bandwidth of the phase-locked loop; and generating a phase compensation signal, and performing time-varying channel minimum mean square error equalization in combination with a received baseband signal to eliminate inter-symbol interference. The system integrates a phase noise monitoring function module, a channel parameter estimation function module, a phase-locked loop bandwidth regulation function module, a phase compensation generation function module and an interference joint elimination function module. By means of dynamic bandwidth reconstruction and high-precision phase compensation, the bit error rate under high-speed movement is remarkably reduced, the 5G millimeter wave communication standard requirement is met, and the method has the advantages of being achieved on a whole chip, low in delay and high in robustness.

The invention discloses a vehicle key driving state estimation method based on low-orbit satellite and vehicle-mounted sensing multi-source information fusion, which comprises the following steps: acquiring the real-time longitudinal speed of a vehicle by combining a Doppler frequency shift formula based on a low-orbit satellite measurement signal; acquiring real-time lateral force of the tire based on the intelligent tire measurement signal in combination with a Gaussian process regression algorithm; a tire slip angle is calculated based on a vehicle-mounted sensing signal, a tire cornering stiffness estimation algorithm is established in combination with lateral force prior information, and a real-time cornering stiffness adaptive value is obtained; vehicle parameters and real-time sensing signals are obtained, and a vehicle dynamics model is established in combination with the self-adaptive value of the cornering stiffness; a lateral force estimation value provided by an intelligent tire system, a longitudinal vehicle speed value measured by a low-orbit satellite, a yaw velocity and a transverse acceleration sensing measurement value serve as measurement signals, an innovation self-adaptive expansion Kalman filter is combined, and a vehicle key driving state estimation algorithm is designed. And the real-time side slip angle, the yaw velocity and the longitudinal velocity of the vehicle are obtained.

Systems, apparatus and methods are described for dynamic demodulation signal resource allocation. PDSCH / PUSCH DMRS enhancement is provided. A dynamic indication of reference signal functionality may be provided in a slot for an additional DM-RS. A configured CSI-RS / SRS may be dynamically indicated to use as an additional DM-RS in a slot. Frequency shift / hopping of DM-RS as a function of OFDM symbol and / or the order of OFDM symbol containing DM-RS may increase frequency density within a slot. DM-RS antenna port aggregation may increase DM-RS frequency density. One or more DM-RS antenna ports may be used to demodulate the same layer. PDCCH DMRS enhancement is provided. Frequency shift / hopping of PDCCH DMRS may be provided as a function of a REG index within an REG bundle, OFDM symbol index, etc. Use of multiple types of REG (e.g., low and high DM-RS) and REG type may be determined based on subcarrier spacing, operating frequency band, etc.

The invention provides an underwater ultrasonic signal analysis method based on the Doppler effect, and relates to the technical field of data processing, and the method comprises the steps: carrying out the segmentation processing of echo signal data according to a preset time window, carrying out the envelope demodulation and phase unwrapping operation of a signal in each time window, and carrying out the phase unwrapping operation of the signal in each time window; amplitude sequence, phase sequence and instantaneous frequency sequence data are extracted; extracting frequency change, amplitude change and phase change data, performing clustering processing, and distinguishing and marking different underwater target components; respectively calculating an amplitude stability index and a phase change synchronism index for each frequency track in all time windows, and screening a main frequency track according to the amplitude stability index and the phase change synchronism index; frequency shift values in the time windows are extracted, the speeds of the underwater targets in the time windows are calculated based on the Doppler effect, and the motion direction is judged in combination with frequency change data and phase change data; according to the invention, the autonomy and accuracy of underwater ultrasonic signal analysis are improved.

The gallium nitride-based semiconductor laser comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper limiting layer which are sequentially arranged from bottom to top. According to the semiconductor laser element, the multi-vacancy electron phonon regulation and control layers of a multi-layer structure are arranged in the semiconductor laser element, and the electron affinity distribution characteristic and the polarization optical phonon energy distribution characteristic of each multi-vacancy electron phonon regulation and control layer are limited, so that single-vacancy, vacancy group and multi-vacancy regulation and control electron phonon structures are formed; the electron phonons are localized between the lower limiting layer and the lower waveguide layer, stokes frequency shift formed by photon energy difference between pump light and oscillation light is reduced, phonon vibration and phonon transport heat loss are reduced, the heat dissipation performance of a laser element is improved, thermal mismatch between epitaxial layers is improved, the thermal lens effect and stress birefringence effect of the laser are inhibited, and the laser efficiency is improved. The problems of laser beam distortion and depolarization are improved, and the laser beam quality factor is improved.

The invention discloses a distribution network power line anti-interference communication method based on adaptive filtering, and belongs to the technical field of distribution network power line communication. According to the method, a communication signal adopting a frequency shift keying modulation mode is acquired from a power line coupler of a distribution network through a signal acquisition module, the communication signal is preprocessed by using a digital signal processing unit, spectral analysis is performed on the preprocessed signal, and characteristic parameters of interference noise are extracted; a coefficient vector of a finite impulse response adaptive filter is initialized based on the characteristic parameters, the order of the filter is in direct proportion to the reciprocal of the dominant interference frequency, fine adjustment is carried out based on noise energy distribution through a table look-up method or a linear mapping relation, and the weight coefficient of the filter is adjusted in real time in the communication process. The adjustment step length is dynamically adjusted according to the real-time estimated signal-to-noise ratio, and finally, the processed signal is output through the adaptive filter and data demodulation is carried out. The method is mainly used for improving the anti-interference capability and the communication reliability of the power private line communication of the distribution network.

The invention relates to a SiC crystal ingot facet detection method based on Raman combined with resistivity detection, which comprises the following steps: S1, providing a silicon carbide workpiece, acquiring resistivity rho k of different detection areas on the surface layer of the workpiece based on a preset resistivity detection scanning path, and further preliminarily screening out resistivity abnormal areas; s2, on the basis of a preset Raman detection scanning path, obtaining the edge area on the surface layer of the workpiece, the Raman characteristic peak frequency omega ij of different detection points of the resistivity abnormal area obtained in the S1, a detection image, and an XY coordinate position on an XY plane perpendicular to the height direction of the workpiece; and S3, based on a preset n-rho inverse proportion function model of the doping concentration n and the resistivity rho, and a delta omega-n linear model of the Raman frequency shift delta omega and the doping concentration n, determining and associating the XY coordinate positions of the S2 and the corresponding resistivity rho ij, and constructing a resistivity distribution diagram of the surface layer of the workpiece. The method has the advantages of small detection error and short detection time.

The invention belongs to the technical field of wireless communication networks, and discloses a wireless signal testing method and system for an unmanned vehicle. The method comprises the steps of synchronously collecting electromagnetic signals inside and outside a vehicle, and generating an electromagnetic observation data set; constructing a calibration observation matrix based on a vehicle attitude, position information, a road side reference signal and a communication link state, extracting a candidate interference cluster set and constructing a power curve, and calculating a Pearson's correlation coefficient and Doppler frequency shift to identify an interference type label; determining an interference source position of each interference cluster by adopting a corresponding interference source positioning algorithm according to the interference type label; comprehensively evaluating the communication reliability of the wireless link of the whole vehicle by combining all interference source positions, corresponding labels and power curves and fusing communication link performance indexes and vehicle state information; according to the invention, accurate identification and traceability of wireless link interference of the unmanned vehicle are realized, and the accuracy and real-time performance of communication reliability evaluation are improved.

The invention discloses a millimeter wave signal phase noise testing method based on ultra-stable laser, and the method comprises the steps: generating the ultra-stable laser through employing a common-cavity Brillouin laser frequency stabilization technology, taking the ultra-stable laser as a carrier wave, and carrying out the double-sideband modulation of a to-be-tested millimeter wave signal; frequency shifts of the two sidebands are different, the sideband with high frequency has more downward frequency shifts, the sideband with low frequency has less downward frequency shifts, the generated common-cavity Brillouin laser and the double-optical-sideband pumping laser are coupled and separated to obtain upper and lower double-sideband optical signals with different frequency intervals, and then beat frequency and mixing frequency are performed to generate an intermediate frequency signal with MHz magnitude; the noise characteristic of the intermediate frequency signal directly carries the phase noise of the to-be-tested signal, and the phase noise analyzer carries out noise spectrum density analysis and quantitative evaluation on the intermediate frequency signal to complete the phase noise test of the to-be-tested millimeter wave signal. The collaborative optimization problem that the reference source stability, the system noise and the to-be-tested signal noise are difficult to separate in the ultrahigh frequency signal noise test is solved.

The invention provides a laser radar ranging method based on parallel detection, which relates to the technical field of laser radar ranging, and comprises the following steps: generating N lasers with different wavelengths, splitting beams by a beam splitter, separating optical channels with N independent wavelengths by a demultiplexer, performing frequency shift processing, combining N paths of optical signals after frequency shift through a beam combiner, and combining the N paths of optical signals after frequency shift through a beam splitter; generating a beam of composite reference light containing N wavelengths, wherein each wavelength has a specific frequency shift; signal light returned from a target and the composite reference light are jointly input into a coupler for frequency mixing so as to generate an optical beat frequency signal, and operation processing is performed to calculate the target distance and the target radial speed corresponding to each wavelength. According to the laser radar ranging method provided by the invention, parallel detection of the laser radar can be realized, beat frequency signals corresponding to a plurality of different wavelengths can be distinguished only by integrating a group of detectors, a cross-group amplifier and an analog-to-digital converter, the cost is greatly reduced, and the complexity of the system is reduced.

The invention belongs to the technical field of communication, and particularly relates to a high-robustness multi-channel frequency shift Chirp modulation signal generation method and system for a time-frequency doubly selective channel. The method comprises the following steps of: 1, calculating robust code digits based on statistical characteristics of time delay and Doppler frequency shift of an ionized layer channel; 2, based on the number of robust code bits in the step 1, setting an address code, and realizing RO-MFSCM signal mapping of binary information bits; 3, modulating and transmitting the RO-MFSCM signal based on the information mapping in the step 2, thereby realizing the transmitting process of the RO-MFSCM signal; step 4, based on the emission signal in the step 3 and the robust code digit in the step 1, the receiver carries out robust domain energy aggregation on the RO-MFSCM signal; and step 5, based on the multi-channel robust domain energy aggregation signal in the step 4, adopting a multi-channel parallel demodulation algorithm and de-mapping to realize the receiving process of the RO-MFSCM signal under the time-frequency doubly selective channel. The method aims at the transmission fading problem of the FSCM signal in the ionosphere time-frequency doubly selective channel.

The invention discloses a high-frequency transformer transmission extreme value frequency rapid calibration and tolerance analysis method, which comprises the following steps of collecting operation parameters of a high-frequency transformer in real time, performing standardized preprocessing, and integrating the preprocessed parameters to construct operation condition vectors in a unified format; defining a frequency response range of the high-frequency transformer, constructing a frequency search space based on the frequency response range, and establishing a target function for fitness evaluation based on the frequency search space; searching extreme value frequency points in the frequency search space by adopting a quantum evolutionary algorithm; based on the working condition vector and the extreme value frequency point, a working condition frequency deviation prediction model is constructed, and the working condition frequency deviation prediction model outputs an extreme value frequency shift offset; and calculating the dynamic tolerance bandwidth according to the predicted offset and the fluctuation range of the working condition vector. According to the invention, rapid and accurate calibration of the extreme value frequency of the high-frequency transformer and dynamic determination of the tolerance range can be realized.

The invention discloses a method and a system for measuring gravitational potential by a satellite-air-ground optical clock time-frequency comparison system. According to the method for measuring the gravitational potential, an optical clock superior to 110-18 orders of magnitude serves as the basis, a free space time-frequency comparison link based on an optical frequency comb serves as a bridge, the optical clocks among the satellite, the air and the ground are connected, high-precision time-frequency transmission is carried out, a gravity frequency shift signal is accurately extracted through time-frequency comparison of a remote clock, and the gravitational potential is measured. And then the gravity potential difference of the position where the remote clock is located is obtained by using a gravity frequency shift equation, and the gravity potential difference between air and ground or between any ground stations is determined.