1223 results about "Phase difference" patented technology

A method for quality inspection of an etching paste material based on a spectral response difference, including: identifying a position of density mutation boundary through spectral collection and density gradient analysis. Applying a specific frequency beam to obtain the resonance response parameter, generating stress field reconstruction data. Performing a reverse optical tracking to obtain a defect formation path, generating degradation prediction data. Establishing a self-organizing optical monitoring grid, to form a hierarchical spectral fingerprint library. Constructing a multi-point linked defect blocking network, to form an interconnected optical energy field. Monitoring a cooperative response to obtain network stability data, Identifying abnormal position coordinates based on a material quality grade and the network stability data, obtaining the abnormal position coordinates. Performing a phase adjustment to obtain a phase difference spectral set, conducting a phase comparison marking on the abnormal position coordinates, completing the quality inspection of the etching paste material.

The invention discloses an unmanned aerial vehicle signal identification method and system in a complex electromagnetic environment, and belongs to the field of unmanned aerial vehicles. According to the invention, the form of the liquid metal channel of the liquid metal antenna is adjusted to adapt to the target frequency band, and regional electromagnetic signals are collected in all directions. And generating spatial distribution data including the unmanned aerial vehicle and the interference direction based on the phase difference and preset features. The deformation of the liquid metal droplets is regulated and controlled through the electrowetting voltage, so that the antenna main lobe is aligned with the unmanned aerial vehicle, and the side lobe suppression area covers an interference source. Then, a target direction signal set is collected, and time domain fluctuation, frequency domain distribution and spatial domain direction multi-dimensional features are extracted; and inputting the multi-dimensional features into a joint probability model constructed by a Bayesian network, and outputting posterior probability information. Markov chain Monte Carlo self-adaptive sampling is utilized, the classification confidence coefficient is calculated through iterative convergence, the signal category is judged according to a threshold value, and the unmanned aerial vehicle signal recognition accuracy can be improved in the complex electromagnetic environment.

The invention relates to an electromagnetic shielding method and shielding system for power distribution, and belongs to the technical field of electromagnetic shielding. Comprising the following steps: establishing a shielding model corresponding to the shielded room according to volume data of the shielded room; simulating and positioning electromagnetic wave conditions in the shielded room in the shielding model; selecting key detection points; constructing a phase difference matrix; shielding requirements of different waveforms in the same frequency band are distinguished, leakage path positioning based on a waveguide equation is carried out, and a core leakage area and an auxiliary protection area are divided. According to the electromagnetic shielding method and shielding system for power distribution provided by the invention, the dynamic adaptability of electromagnetic shielding and the detection capability of transient electromagnetic pulses are remarkably improved, and a multi-dimensional risk quantification and differentiation reinforcement strategy is realized. Meanwhile, intelligent materials and a dynamic optimization mechanism are adopted, the material utilization rate and the protection effect are improved, and a reinforcing effect feedback closed loop is formed.

The invention discloses a cable defect detection method and system based on double-path coupling frequency domain reflection, and the method comprises the steps: enabling a signal generator to generate two groups of correlated sine frequency sweeping signals, namely a test signal S1 and a reference signal S2; s1 is injected into the head end of the cable, and a reflected signal R1 is collected; respectively extracting the spectrum characteristics of the amplitudes and the phase differences of the R1, the S1 and the S2 by adopting a double-path signal comparison device, carrying out comprehensive judgment, and determining the reflection spectrum characteristic of the R1; the reflection coefficient spectrum is optimized through a window function, and signal features are obtained; converting the optimized frequency spectrum into a time domain reflection waveform, and extracting reflection peak time information; and calculating defect positions by combining electromagnetic wave propagation velocity. According to the cable defect detection method and system based on double-path coupling frequency domain reflection, high-precision detection of a long-distance cable is realized; and two paths of coupling signals are introduced for comparison, so that the accuracy of phase measurement is improved, and an efficient nondestructive detection scheme is provided for power grid operation and maintenance and the like.

The invention relates to the technical field of detection, in particular to a complex shell detection method and system based on structured light scanning. The method comprises the following steps: calculating a wrapped phase value and a phase modulation amplitude of each pixel point under each frequency, calculating discrete probability distribution containing candidate stripe series and a corresponding probability for each pixel point based on a multi-frequency wrapped phase difference, generating an initial pixel confidence map, and constructing an energy function; the penalty weight of the smooth item is determined according to the phase modulation amplitude and the wrapped phase gradient local variance, obtaining an initial fringe order distribution diagram, updating discrete probability distribution by using an initial pixel confidence map, re-minimizing an energy function to obtain a corrected fringe order distribution diagram, and reconstructing a final three-dimensional shape. And iteratively optimizing a projector principal point and a radial distortion coefficient in system calibration parameters. According to the scheme, the geometric details of the surface can be reserved, and the processing effect and the measurement precision of the complex curved surface and the high-curvature area are improved.

The invention belongs to the technical field of digital holographic measurement, and particularly relates to an optical element stress measurement and defect identification method based on a digital holographic photoelastic method. The method is realized based on a transmission-type off-axis digital holographic light path system; light beams emitted by the laser assembly are divided into reference light and object light, the object light is reflected by the surface of a sample and carries sample information, the object light and the reference light intersect in front of the CMOS camera to generate interference, the CMOS converts an interference light intensity signal into an electric signal, and holographic image processing is performed by the computer; the hologram before and after external force loading is reconstructed to obtain surface topography distribution, and the reconstruction precision is improved through the steps of positive first-order spectrum extraction, angular spectrum reconstruction automatic focusing and the like; the phase difference before and after external force loading is calculated through reconstruction complex amplitude phase extraction, and then the direction and size distribution of the principal stress of the sample are measured and calculated based on a digital photoelastic method and a stress optical law; and the defect of the optical element is identified by measuring the stress value change under the same external force loading, so that the method has important practical significance.

The invention provides a broadband tunable low-phase-noise photo-generated microwave signal source and device, and relates to the technical field of photo-generated microwaves. According to the invention, a low-frequency optical pulse and a high-frequency microwave signal are respectively input into the electro-optical sampling phase-locked loop; and the electro-optical sampling phase-locked loop determines the synchronization error of the optical pulse and the microwave signal based on the phase difference between the optical pulse center point and the microwave signal zero crossing point. And taking the synchronization error as a feedback signal, and continuously adjusting the frequency and the phase of the microwave signal by the voltage-controlled oscillation module until the frequency and the phase are synchronized with the Nth harmonic of the optical pulse. By setting different initial frequencies of the voltage-controlled oscillation module, microwave signals with different integral multiple optical pulse frequencies can be obtained, and broadband tuning of photo-generated microwave signals is realized. Furthermore, the repetition frequency of the frequency comb is locked through beat frequency of two beams of reference laser and two adjacent comb teeth, the stability of the reference laser is transmitted to the optical pulse, and the stability of the reference laser is further transmitted to the microwave signal through synchronization of the optical pulse and the microwave signal, so that the phase noise of the photo-generated microwave signal source is reduced.

The invention relates to the technical field of flow chart automatic testing, and provides a flow chart automatic testing method, system and device of a control system and a storage medium so as to solve the problems of low testing efficiency and poor accuracy. The method comprises the following steps: acquiring a film thickness and transverse tension fluctuation curve by using an intelligent textile sensor array, generating a tension compensation factor based on a phase difference to correct the film thickness, and establishing a thickness distribution topology model; performing non-contact scanning by using a terahertz wave emission array, and activating a defect mark cluster when Doppler frequency shift is detected; transmitting the thickness distribution model and the defect characteristics to a test platform, reconstructing a control logic and generating a test script, and realizing a virtual-real synchronous test through a communication protocol; and generating a process parameter correction factor according to a test result, and feeding back the process parameter correction factor to the distributed control system to optimize the tension closed-loop control module, and generating a matched terahertz verification map. According to the technical scheme provided by the invention, the efficiency and accuracy of automatic testing of the flow chart can be improved.

The invention discloses a three-degree-of-freedom measurement method based on a planar two-dimensional time grating sensor, and the method comprises the following steps: enabling a movable ruler base body and a fixed ruler base body to be installed in a parallel and opposite manner, and leaving a certain gap between the movable ruler base body and the fixed ruler base body; after same-frequency and equal-amplitude sine excitation signals with the phase difference of pi / 2 are applied to the four-phase excitation electrode groups on the fixed ruler base body respectively, the movable ruler base body moves in the X direction and the Y direction and deflects around the Z axis relative to the fixed ruler base body; the single sensing unit on the movable ruler base body can solve output signals deflecting in the X direction and the Y direction and around the axis, the output signals of all the sensing units are subjected to combined operation, and displacement values of the movable ruler base body in the X direction and the Y direction and the deflection angle theta can be decoupled. According to the method, displacement measurement in the X direction, the Y direction and the deflection angle around the Z axis can be achieved through combined calculation between the induction units on the movable ruler base body, the calculation speed is high, interference can be further eliminated, and the measurement precision is improved.

The invention provides a cold atom gravity measurement method and device based on entangled state enhancement, and belongs to the technical field of cold atom gravity measurement, and the method comprises the steps: carrying out the excitation of a nonlinear crystal, obtaining an entangled photon pair, and enabling the entangled photon pair to comprise a first photon and a second photon in an entangled state; laser parameters of an area where a cold atomic group is located are controlled, the first photons are coupled into the cold atomic group, and a plurality of cold atoms in an entangled state are obtained; and placing the plurality of cold atoms in the entangled state in a gravity field, measuring the phase difference of the cold atoms under the action of the gravity field, and determining a gravity measurement result based on the phase difference. According to the invention, entangled photons are introduced to be coupled with cold atoms, so that the measurement limit is improved to the Heisenberg limit, and higher-precision gravity measurement is realized.

The invention discloses a weight function phase shift method for deformation field measurement, belongs to the technical field of optical measurement, is suitable for phase extraction and deformation field measurement of periodic structure images such as gratings and stripes, and has the characteristics of high speed and high precision. Weight function windows (a rectangular window, a triangular window, a cosine window and a Gaussian window) are applied in image processing, discrete Fourier transform is carried out after pixel gray values in the windows are multiplied by corresponding weights, and image phases at the center pixel positions of the windows are obtained. After the weight function window traverses all image pixels, the phase distribution of the whole image is obtained. And solving an image deformation field by using the phase difference of the images before and after deformation. Compared with the existing phase-based deformation field method, the method does not need complex image processing operation, and can solve the high-precision phase in one step and obtain full-field deformation only by using the weight function and the global pixel gray scale.

The invention discloses a transparent part defect detection method and system based on dual-optical-path phase deflection, and belongs to the technical field of optical detection. The system comprises a camera, a reflection light source, a spectroscope, a backlight light source and a processing unit. The detection method comprises the steps of primary measurement, product overturning, secondary measurement and defect comprehensive analysis and classification. A depth map and a modulation degree map of the surface of a product are obtained through reflective measurement, a phase difference map and a backlight modulation degree map are obtained through transmission-type zero reference surface differential measurement, multi-dimensional data are fused, and accurate detection and classification of concave and convex points, foreign matter, scratches and other defects are achieved according to preset logic. The method can effectively eliminate inherent errors of the system, realizes double-sided full detection without omission, is high in detection precision and accurate in defect classification, and is suitable for defect detection of transparent parts such as multilayer transparent glass.

The invention discloses a real-time automatic focusing hyperspectral acquisition method and a real-time automatic focusing hyperspectral acquisition device. The real-time automatic focusing hyperspectral acquisition method comprises the following steps: step 1, acquiring dark background pixel signals; 2, automatic focusing is carried out; 3, repeating the step 2 until the requirement is met, recording automatic focusing data, and performing spectrum acquisition to obtain original spectrum data; step 4, calculating a full-width object distance matrix of the original spectral data based on the phase difference finally obtained in the step 3; 5, correcting the original spectral data based on the full-width object distance matrix to obtain corrected spectral data; and step 6, calculating the corrected reference plate spectral data based on the corrected spectral data and the dark background pixel signal, calculating the reflectivity of the target object to be measured, and realizing real-time automatic focusing hyperspectral acquisition. The method innovates a phase difference analysis method, and efficiently processes light change and target offset in a dynamic scene; the combination of the two improves the focusing precision and stability, effectively solves the problem that the scanning target in the dynamic scene is liable to defocus, and achieves the efficient adaptation of the dynamic scene.

The invention provides a dynamic high-precision PTP (Precision Time Protocol) time synchronization system realized based on an FPGA (Field Programmable Gate Array), which comprises a master device and a slave device, and the master device and the slave device are connected through a PHY (Physical Layer) to carry out PTP time synchronization; the master device and the slave device have the same structure and comprise an FPGA and a voltage-controlled crystal oscillator; in the master device, the FPGA obtains the frequency difference and the phase difference between the master device and an externally input reference source, further adjusts the frequency of a voltage-controlled crystal oscillator, corrects a local time mark, and sends a PTP message to the slave device; and in the slave equipment, the FPGA obtains the frequency difference and the phase difference between the slave equipment and the master equipment based on the received PTP message, so that the frequency of the voltage-controlled crystal oscillator is adjusted, and the local time scale is corrected. According to the invention, low-cost and high-precision PTP time synchronization is realized.

The invention discloses a gas pipeline leakage source positioning method, and relates to the field of gas leakage detection. According to the method, acceleration signals and sound wave signals are collected through sensors arranged at detection points, peak value extraction is carried out in respective corresponding frequency domain complex spectrums through data preprocessing, and main frequency signals and frequency multiplication signals are obtained; distinguishing real leakage and interference signals according to the stable frequency integral multiple relation characteristic and time sequence consistency of the two signals; the phase difference is calculated by extracting the phase of the dominant frequency signal and the phase of the corresponding frequency multiplication signal, and the position of the leakage source relative to the detection point is calculated by combining the path sound velocity. The method can capture small distance differences, effectively improves the precision and robustness of leakage positioning, and is suitable for online leakage monitoring and diagnosis of gas or liquid medium pipelines.

Disclosed is a technology related to a low noise amplifier applied between an RF receiver and an RF switch. A phase difference matching circuit having the same phase difference as a positive gain amplifier is added to an output terminal of an attenuator of a low noise amplifier having a variable gain switching structure. In addition, a variable impedance circuit connected to an output terminal of the positive gain amplifier and an output terminal of a phase difference matching unit to finely adjust the phase difference of each output terminal may be further included.

The invention relates to the technical field of on-line monitoring, in particular to an insulation fault on-line monitoring method and system for a medical IT system control cabinet. The method comprises the following steps: selecting a non-integer frequency multiplication detection frequency according to equivalent ground distributed capacitance in a previous monitoring period, and superposing the non-integer frequency multiplication detection frequency with a fundamental frequency to form a composite signal injection system; collecting signals to calculate a voltage instantaneous harmonic distortion rate change gradient, and selecting a time window to split the leakage current according to the change gradient; on the basis of dispersion estimation signal-to-noise ratio weighted fusion current vectors, insulation resistance and distributed capacitance are calculated; constructing a four-dimensional original feature vector composed of the insulation parameter, the phase difference and the intermodulation component energy; constructing a diagonal weighting matrix based on the resistance-capacitance ratio and the gradient to transform a feature vector, and determining the fault attribution through the Mahalanobis distance calculation with the fault template library. According to the scheme, harmonic interference can be avoided, calculation stability can be improved, insulation instantaneous sudden change can be quickly responded, and different fault types can be accurately distinguished to guide maintenance.

The invention discloses a liquid metal electromagnetic flowmeter capable of eliminating the influence of an environmental magnetic field and a use method. The flowmeter comprises a flow channel, a magnet exciting coil, a first environment magnetic field eliminating coil, a second environment magnetic field eliminating coil, a first signal receiving coil, a second signal receiving coil and a measuring device. Induced electromotive forces generated by an environment magnetic field on the four induction coils are equal, and the electromotive forces of the elimination coil and the signal receiving coil are superposed and counteracted through a specific connection mode, so that the influence of the environment magnetic field is reduced, and the signal-to-noise ratio is improved. When the flow needs to be measured, firstly measuring the phase difference, then adjusting the frequency to determine the working frequency, obtaining the relationship between the flow velocity and the phase difference, inputting the relational expression, finally measuring the phase difference, performing interpolation calculation to obtain the flow velocity, and calculating the volume and mass flow by combining the geometric parameters of the flow channel and the liquid metal density. The device and the method have the advantages of wide measurement range, high precision, strong applicability and the like, are suitable for various environmental magnetic fields and flow channel sizes, are higher in measurement precision and are stable, and measurement signals are not influenced by corrosion of working media.

The invention discloses a low-power-consumption winch sensor based on a tunneling magnetoresistance effect. The low-power-consumption winch sensor comprises a measurement module, a signal conversion unit, a shell, a mandrel, a magnetic rotary disc and a detection assembly. The magnetic turntable and the mandrel are connected and rotate synchronously, the detection assembly comprises a TMR sensing element and N magnets, and the magnetic turntable is provided with mounting blind holes for embedding the magnets; the TMR sensing element is arranged on the shell and comprises a mounting plate and two sensing units, the magnetic domain directions of the two sensing units are perpendicular to the rotation axis, magnetic resistance signals of the two sensing units are converted through the signal conversion unit and input into the measuring module, the horizontal distance between the centers of the two sensing units and the magnet and the rotation axis is R, and the center distance L of the two sensing units is smaller than R * sin (180 degrees / N); the sensor is based on the TMR tunneling magnetoresistance effect, is high in detection sensitivity and low in energy consumption, outputs square wave signals with phase differences, can be used for a measurement module to accurately analyze and calculate the rotating speed and the rotating direction of a winch roller, is simple in overall structure, small in radial size and easy to install, and the installation precision is controlled.

The invention provides a co-path optical path laser ranging system and method for correcting an absolute distance based on a phase method. An arbitrary waveform generator is adopted to perform frequency modulation on a laser signal of a semiconductor laser; the object light and the reference light reflected by the optical fiber collimation unit are transmitted in a common-path manner, and are transmitted to the processor through the loop unit, the photoelectric detector and the data collector; the processor extracts a beat frequency signal of the interference light, obtains an absolute distance according to a frequency modulation continuous wave distance measurement principle, obtains an updated absolute distance after a target moves, and calculates a phase difference to obtain a relative distance measurement value based on an intensity signal of the interference light corresponding to a position before and after the target moves; and correcting the absolute distance measured twice by using the relative distance measurement value to obtain the corrected twice absolute distance. The advantages of a frequency difference method and a phase difference method are combined, a high-precision measurement result can be obtained, the problem of phase ambiguity can be avoided, and precision requirements and measurement requirements of different occasions can be met.

The invention discloses an analog Doppler frequency shift and arrival angle measuring device and method based on Rydberg atoms, and in the aspect of DFS measurement, the device performs beat frequency on two signals to obtain an intermediate frequency signal frequency which is a DFS value; the device calculates the AOA of the echo signal by measuring the phase difference of the echo signal at two different positions in the cesium gas pool. According to the invention, simultaneous measurement of DFS and AOA can be realized, and the scheme has the advantages of simple structure, stable system, multifunction, anti-interference and the like, and has great application prospects in electronic reconnaissance and countermeasure systems and the like.

The invention relates to the technical field of welding seam defect detection, and discloses a welding seam defect detection method, device and equipment based on three-dimensional holographic scanning. Coherent light is used for irradiating a welding seam to be detected, a reference state hologram sequence and a loading state hologram sequence are generated, a phase difference field is calculated, and the deformation gradient is analyzed; marking a first abnormal region and extracting a deformation concentration ratio and a spatial distribution mode, calculating a dominant spatial frequency through space-frequency domain joint analysis, fusing abnormal features, marking a second abnormal region and extracting amplitude distribution and spatial continuity parameters, and performing defect characterization analysis by combining information of the first and second abnormal regions to obtain weld defect detection information. The method has the advantages of high precision, non-contact and real-time monitoring, the accuracy and efficiency of weld defect detection can be effectively improved, and the problem that weld detection is not accurate enough in the prior art is solved.

The invention discloses a low-harmonic high-voltage speed regulation system based on a multi-pulse phase-shifting transformer, and particularly relates to the field of power electronic technology and motor speed regulation, which is characterized in that the primary side of the multi-pulse phase-shifting transformer is in star connection, and N groups of windings on the secondary side are in extended delta connection, so that phase difference is realized; the multi-path low-voltage alternating current is converted into multi-path low-voltage alternating current and low-order harmonics are High voltage is output through cascade H-bridge topology series connection, and reliable conversion is guaranteed through rectification filtering inversion and device redundancy design; the motor control module collects signals through multiple sensors, and PWM drive signals are generated through a vector control algorithm and coordinate transformation. The harmonic detection and compensation module detects harmonic waves based on an FFT algorithm, and injects a reverse compensation component through a modulation strategy to offset the harmonic waves; and the auxiliary protection module integrally realizes low-harmonic and high-precision high-voltage motor speed regulation through multi-dimensional monitoring and hardware protection.

The invention relates to the technical field of photoelectric detection, and particularly discloses a three-dimensional defect detection method and system based on compound color stripe projection, and the method comprises an upper computer control and processing module which is used for generating a compound color stripe pattern coded with phase difference information, and coordinating and controlling the synchronous operation of the whole system; the structured light projection module is used for receiving the composite color stripe pattern and projecting the composite color stripe pattern to the surface of a measured object at one time; the imaging module is used for receiving the composite colored light reflected after being modulated by the surface of the measured object and separating the composite colored light into monochromatic light signals with different colors for synchronous acquisition; the imaging module further comprises an active highlight suppression unit which is used for dynamically adjusting the polarization direction according to an instruction of the upper computer control and processing module so as to suppress highlight caused by specular reflection. Multiple groups of sine fringes with fixed phase differences are projected to the surface of a measured object at one time. And a plurality of deformed fringe patterns with phase displacement can be synchronously acquired under single exposure.

The invention provides a Mach-Zehnder interferometer optical fiber sensor based on an arc-shaped concave cavity single-mode optical fiber. The device is characterized by comprising an incident optical fiber 1, a beam splitter 2, an interference arm 3, a beam combiner 4 and an emergent optical fiber 5 which are connected in sequence. The incident optical fiber 1 is used for transmitting an input optical signal, the beam splitter 2 couples the optical signal in the incident optical fiber 1 into the interference arm 3, the interference arm 3 is used as a transmission waveguide, three arc-shaped concave cavities with different depths and curvature radiuses are arranged in the interference arm 3, and when a solution to be detected is immersed in the concave cavities, the refractive index change modulates an interference spectrum through an optical path difference and a phase difference; according to the design of the three concave cavities, refractive index distribution of three independent positions in the reaction process can be measured at the same time, the beam combiner 4 recombines optical signals in the interference arm 3 and couples the optical signals into the emergent optical fiber 5, and the emergent optical fiber 5 is responsible for outputting the optical signals and transmitting the optical signals to detection equipment for analysis. According to the invention, multi-position synchronous detection is realized through the multi-cavity gradient sensitive characteristic and in combination with the femtosecond laser micromachining technology, the problem of accidental errors of a traditional single-position sensor is solved, and the sensor is suitable for scenes such as microfluidic reaction requiring dynamic monitoring of refractive index change.

The invention discloses an on-line brightness uniformity automatic test method and system, and relates to the technical field of brightness test, and the method comprises the following steps: obtaining a stroboscopic signal of an illumination light source in a test environment, and extracting the stroboscopic characteristic frequency of the illumination light source through a frequency domain analysis algorithm, establishing a phase tracking baseline between the frequency of the illumination light source and a sampling clock of the optical detection equipment, and constructing a phase difference mapping matrix based on the baseline; and based on the phase difference mapping matrix, constructing a self-correction model of the sampling clock of the optical detection equipment. Through phase tracking and self-correction control, optical sampling and illumination frequency are synchronized for a long time, brightness fluctuation caused by stroboscopic aliasing is eliminated, and measurement stability and consistency are improved; and through frequency domain residual suppression and brightness index re-calibration, closed-loop control from sampling to output is realized, so that the detection result is higher in precision, the judgment is more reliable, and accurate support is provided for brightness detection and quality tracing of a production line.

The invention provides an azimuth transverse wave remote detection data processing method, system and device and a medium. The method comprises the steps that an instrument is adopted to collect novel four-component transverse wave data (xx, xy, yx and yy) of a target well section; under a coordinate system (x, y) of the instrument, synthesizing an XX reflected wave signal with an angle defined relative to the x-axis direction of the instrument by using the orthogonal dipole four-component reflected signal, and defining the XX reflected wave signal as an angle when the reflected wave signal reaches the maximum amplitude; obtaining two cross component signals xy and yx by using novel four-component shear wave data (xx, xy, yx and yy), performing sliding windowing on the cross component signals xy and yx, performing Fourier transform on the signals in the window to obtain phase spectrums, and comparing the phase spectrums of the two cross component signals to obtain an actual phase difference; according to a novel four-component data combination mode, changing the orientation of the reflector, theoretically calculating the theoretical phase difference between the two cross component signals xy and yx, and establishing a rule chart of the cross component signals along with the orientation change of the reflector outside the well based on the theoretical phase difference; and judging the real azimuth angle of the reflector according to the rule plate.

The invention discloses an ODAC implementation system and method based on a five-segment thermo-optical phase modulator, and relates to the technical field of optical communication, and the method comprises the following steps: obtaining single-mode laser input, dividing the single-mode laser input into two paths through a multi-mode interference device beam splitter, and transmitting the single-mode laser input into an upper arm and a lower arm of a Mach-Zehnder modulator; the current is adjusted through the thermo-optic phase modulator to control the temperature, the refractive index is changed to introduce phase delay, and the phase difference of two arms of the Mach-Zehnder modulator is calibrated; on the basis of a five-segment thermo-optical modulator, hierarchical amplitude modulation is carried out on beam splitting light according to digital input, a phase space is constructed by utilizing weight combination, and a linear optimal discrete state is screened; the modulated light is combined by a multi-mode interference device beam combiner, and digital-analog mapping output of light intensity is carried out; a detector installed at an output port of the five-segment thermo-optical phase modulator is used for monitoring output optical power in real time, the output optical power is fed back to a control circuit to calculate errors, thermo-optical modulation current is dynamically adjusted to compensate offset point drift, and optical digital analog conversion is achieved.

The invention relates to the technical field of ultrasonic imaging, and discloses a three-dimensional ultrasonic imaging method and system, a terminal and a medium, and the method comprises the steps: controlling a two-dimensional array probe to sequentially emit a plurality of three-dimensional ultrasonic beams which have incompletely same wavefront curved surface shapes and are in forward and backward reciprocating alternating sequences in the dimension of a wide wave beam; the method comprises the following steps: performing three-dimensional beam forming on collected original channel data to obtain multiple pieces of three-dimensional intermediate imaging data after beam forming, and performing clutter filtering and phase difference correction on the three-dimensional intermediate imaging data to obtain a three-dimensional coherent composite image; the problems that three-dimensional ultrasonic imaging is difficult to choose between time resolution and space resolution and imaging quality is not ideal are solved, phase difference artifacts generated by a moving target can be eliminated, and a three-dimensional ultrasonic image with better resolution and signal-to-noise ratio is obtained.