42 results about "Absolute phase" patented technology

The invention relates to a method and a system for inhibiting strong mutual reflection based on polarization complementary logic coding. The method comprises the following steps: acquiring calibration parameters of a camera and a projector; generating a polarization phase shift stripe based on the calibration parameter, designing a high-frequency complementary logic code word, and embedding the high-frequency complementary logic code word into a polarization channel through polarization modulation to obtain a composite stripe pattern; the method comprises the following steps: calculating to obtain a linear polarization degree image through an acquired multi-angle polarization image, extracting a high-reflection region from the linear polarization degree image by adopting an adaptive threshold segmentation method, and carrying out binarization processing on the linear polarization degree image to obtain a binarized linear polarization degree mask; and on the basis of a decoding range of a binary linear polarization degree mask constraint high-reflection region, decoding the composite stripe pattern to obtain absolute phase level information, and performing noise suppression on the absolute phase level information by adopting a self-adaptive threshold algorithm. The method can effectively solve the influence of mutual reflection and high dynamic range of the surfaces of the measured object, and improves the precision and stability of three-dimensional reconstruction.

The invention relates to the technical field of laser control, and provides a high-dynamic-range multi-channel laser interference control method and related equipment. Channel signals of a plurality of target channels are obtained in real time according to a plurality of preset photoelectric detectors, time domain-frequency domain-space three-dimensional sampling is performed on the channel signals to construct an original tensor, joint optimization processing is performed on the original tensor to obtain a noise reduction tensor, phase unwrapping is performed on the noise reduction tensor to obtain an absolute phase matrix, and the absolute phase matrix is subjected to noise reduction processing to obtain an absolute phase matrix. Performing dynamic range expansion on the absolute phase matrix to obtain an enhanced phase matrix, performing multi-wavelength calculation and environment compensation on the enhanced phase matrix to obtain a distance matrix, and performing vibration compensation on the distance matrix to obtain a piezoelectric driving signal. According to the channel laser interference control method, through a series of advanced algorithms and processing means such as multi-dimensional signal acquisition, combined noise reduction optimization, precise phase unwrapping, dynamic range expansion and vibration compensation, comprehensive improvement of laser interference measurement signals is realized.

The invention belongs to the technical field of computer vision and optical measurement, and discloses a three-dimensional reconstruction method and device based on multi-frequency fringe synchronous optimization and a medium, and the method comprises the following steps: based on a monocular structured light system, projecting a plurality of groups of sine fringe images with different frequencies to the surface of an object to be measured through a projector, and carrying out the stepping of a plurality of phases, acquiring a corresponding image sequence by using a camera; using a structured light phase shift method to obtain a relative phase value of a pixel point; obtaining an initial absolute phase value and modulation intensity based on a structured light phase shift method and a multi-frequency heterodyne method; and carrying out joint optimization on the absolute phase and modulation intensity parameters of the multi-frequency fringes through a Gaussian-Newton iteration method. According to the method, the anti-noise capability and the reconstruction precision are improved, a parameter adjustment and threshold recovery mechanism is introduced in the optimization process, the convergence stability and abnormal value elimination are ensured, and the method is suitable for high-precision structured light application scenes such as industrial vision measurement and complex surface detection.

The invention provides an inter-beam bunch signal aliasing calibration method based on a cavity probe. The inter-beam bunch signal aliasing calibration method comprises the following steps: acquiring a non-aliasing reference signal from a high repetition frequency free electron laser device; extracting a signal waveform of each beam bunch and a measurement result thereof from the aliasing-free reference signal; modeling to obtain a residual signal formula; obtaining a calibration result of the beam bunch based on a residual signal formula and a vector calibration algorithm according to the measurement result of the aliasing signal waveform and the standard waveform of the previous beam bunch; taking the next beam bunch as the current beam bunch, and returning to the step of obtaining the calibration result; and obtaining calibration results of all the beam bunches until all the beam bunches are calibrated. According to the method, the amplitude-phase characteristics of the attenuation wake of the adjacent beam bunches are modeled and compensated through the vector calibration algorithm, the time domain aliasing effect in the high-repetition-frequency free electron laser device is effectively eliminated, and the phase absolute deviation measured by the beam arrival time of the cavity probe is reduced to the femtosecond magnitude.

The application discloses a phase unwrapping method and device, system and storage medium, comprising: constructing a U-NetHD absolute phase generation network for directly mapping the wrapped phase to the unwrapped phase; constructing a wrapped phase dataset; training the U-NetHD network by using an unwrapped dataset, unwrapping the interference phase through the absolute phase generation network to obtain an initial unwrapped phase; re-wrapping the initial unwrapped phase and performing conjugate multiplication with the original interference phase to obtain a residual phase; unwrapping the residual phase through an L1 norm unwrapping method to obtain a residual unwrapped phase; and finally, summing the initial unwrapped phase and the residual unwrapped phase to obtain the final unwrapped phase. The technical scheme of the application can solve the problem of low unwrapping precision in low coherence and large gradient regions, and effectively improve the phase unwrapping precision.

This invention relates to the field of dynamic three-dimensional measurement technology for irregular surfaces or contours, and provides a phase-shift-free multi-frequency fringe absolute phase calculation method for dynamic three-dimensional measurement. The method includes two processes: initial phase calculation and phase result optimization. The initial phase calculation process processes the acquired multi-frequency fringe pattern and calculates the absolute phase information of the corresponding pixels. The phase result optimization process uses the constraint of the absolute phase on the multi-frequency fringe pattern equation as a data fidelity term and the modulation degree of the fringe pattern as a smoothing constraint term. Through joint optimization of phase fidelity and modulation degree smoothness, the optimal absolute phase is solved. This invention introduces a multi-frequency fringe pattern combination that satisfies the uniqueness of the optimal phase. While maintaining high measurement efficiency, it comprehensively utilizes its information constraints to improve phase accuracy, thus contributing to high-efficiency and high-precision dynamic three-dimensional measurement.

The application discloses a radar detection method for active electromagnetic regulation and control targets, comprising the following steps: modeling a radar receiving echo signal after a radar transmitting signal is reflected by an electromagnetic super surface arranged on a target to be detected; performing pretreatment on the echo signal to remove a carrier frequency and a frequency modulation, and then performing phase unwrapping processing to obtain an absolute phase; performing window segmentation processing on the absolute phase, estimating a slope of each segmented phase, and taking an average value of the slope of the segmented phase as a slope estimation result of the absolute phase; constructing a phase distribution first-order function by using the slope estimation result of the absolute phase, and subtracting the absolute phase from the phase distribution first-order function to obtain an estimated value of a jump phase term of the electromagnetic super surface; constructing a time-domain phase compensation function according to the estimated value of the jump phase term, multiplying the time-domain phase compensation function with the radar receiving echo signal to obtain a reconstructed signal; and performing matched filtering processing on the reconstructed signal to obtain an output signal.

The present invention discloses a wavefront aberration compensation method based on a nonlinear response cascade model, which uses the frequency reconstruction technology in the process of establishing a Bouc-Wen hysteresis model of a fast steering mirror (FSM). The frequency reconstruction technology can overcome the zero-point drift characteristics of piezoelectric ceramic materials and improve the accuracy and robustness of Bouc-Wen hysteresis modeling. Subsequently, the present invention uses the hysteresis model of FSM for a wavefront corrector with a cascade structure of FSM and a deformable mirror (DM), and proposes a wavefront closed-loop compensation method based on absolute phase distortion based on the model structure of the nonlinear response cascade of the wavefront corrector. Taking absolute phase distortion as the fitting target avoids the accumulation of model errors and hardware noise, so that the wavefront corrector of the FSM and DM cascade can complete the correction of the wavefront with only one closed-loop feedback, thereby improving the compensation capability range, accuracy and efficiency.

The invention relates to a three-dimensional reconstruction method based on DCT (Discrete Cosine Transform) decoding. The method comprises the following steps: projecting a four-step phase shift stripe of a specific code to an object and collecting a deformed stripe; calculating a wrapped phase; the key improvement lies in that after a least square unwrapping model is constructed, improved divergence calculation based on a cosine function is adopted, nonlinear transformation is carried out on a multi-direction wrapped phase gradient so as to suppress noise errors, and an improved divergence field is generated; secondly, performing two-dimensional DCT (Discrete Cosine Transform) forward transformation on the divergence field, and solving an absolute phase field through inverse transformation after operation with a transfer function in a frequency domain; and finally completing three-dimensional reconstruction. The system comprises a projection module, an acquisition module and a processing module. According to the method, non-linear divergence calculation is introduced to be combined with DCT frequency domain solving, the defect that a traditional method is sensitive to noise is effectively overcome, and the reconstruction speed and robustness are improved while precision is guaranteed.

The present disclosure relates to a method and system for suppressing strong mutual reflection based on polarization complementary logic coding. The method includes: obtaining calibration parameters of a camera and a projector; generating polarization phase-shifted fringes based on the calibration parameters, designing high-frequency complementary logic codewords, and embedding the high-frequency complementary logic codewords into the polarization channels through polarization modulation to obtain a composite fringe pattern; calculating a degree of linear polarization map from the collected multi-angle polarization images, extracting high-reflection regions from the degree of linear polarization map using an adaptive threshold segmentation method, and performing binarization processing on the degree of linear polarization map to obtain a binarized degree of linear polarization mask; constraining the decoding range of the high-reflection regions based on the binarized degree of linear polarization mask, decoding the composite fringe pattern to obtain absolute phase order information, and suppressing noise in the absolute phase order information using an adaptive threshold algorithm. The method of the present disclosure can effectively solve the influence of mutual reflection and high dynamic range on the surface of the object to be measured, and improve the accuracy and stability of three-dimensional reconstruction.

The application belongs to the technical field of computer vision and optical measurement, and discloses a three-dimensional reconstruction method based on multi-frequency stripe synchronous optimization, equipment and medium, which comprises the following steps: based on a monocular structured light system, a plurality of groups of sinusoidal stripe images with different frequencies are projected onto the surface of an object to be measured by a projector, and a plurality of phase steps are performed respectively, and corresponding image sequences are collected by using a camera; the relative phase value of a pixel point is obtained by using a structured light phase shift method; initial absolute phase values and modulation intensities are obtained based on the structured light phase shift method and a multi-frequency heterodyne method; and the absolute phase and modulation intensity parameters of the multi-frequency stripe are jointly optimized by using a Gauss-Newton iteration method. By using the above method, the anti-noise capability and reconstruction precision are improved, the parameter adjustment and threshold recovery mechanism are introduced in the optimization process, the convergence stability and abnormal value elimination are ensured, and the method is suitable for high-precision structured light application scenarios such as industrial vision measurement and complex surface detection.

The invention provides a rotation phase multi-period absolute solution algorithm and application thereof, and the algorithm comprises the steps: collecting a first phase signal and a second phase signal with different periods, and processing the first phase signal and the second phase signal into a non-orthogonal oblique track; the track is processed into a plurality of forms, and rotation is carried out through a set rotation angle to change the alignment direction; and discrete section processing and interpolation calculation are carried out on the rotated complex form trajectory to obtain an absolute phase. Multi-period mode phase signals are used for forming a non-orthogonal oblique line track, the direction is aligned through complex numbers and rotation angles, structural normalization is achieved, table look-up and inverse solution modules are removed, the angle can be recovered in real time, the method is suitable for any period combination (including co-prime and non-co-prime conditions), calculation is efficient, and precision is high. The method can be directly deployed in an MCU / FPGA to realize real-time absolute phase calculation.

The present invention discloses a phase denoising method based on noise feature classification. The method reads a fringe image and uses the N-step phase shift method to calculate the corresponding absolute phase, modulation index, and background based on the fringe phase shift frequency and the number of phase shift steps. The calculated data is then used to determine the initial denoising phase. The phase after initial denoising is then used to calculate a phase difference map, and a determination is made as to whether the values ​​in the phase difference map reach the threshold for forming isolated noise to generate a denoising mask 4. The area of ​​each connected domain in the mask 4 is then calculated, and regions with excessively large areas are removed to generate a final denoising mask, which is then used to denoise the phase. The present invention avoids the problem of inaccurate noise removal in traditional phase denoising algorithms, thereby improving the accuracy of phase measurement.

The application discloses a variable-frequency fringe encoding and decoding method and device for rapid three-dimensional measurement and a medium, and belongs to the technical field of computer vision. The method comprises the following steps: in the fringe encoding stage, the optimal encoding pixel offset is obtained according to the target depth range, the fringe frequency and the corresponding phase are determined, the optimal fringe encoding is obtained, and the phase is stored in a lookup table; in the fringe decoding stage, the encoded fringe pattern is emitted to the surface of the object to be measured, the fringe is deformed, the deformed fringe sequence is obtained, the absolute phase is obtained by using a geometric constraint phase unwrapping method, pixel matching is performed through the lookup table established in the fringe encoding stage, and the three-dimensional shape of the object to be measured is restored. The fringe encoding method has the advantages of high precision, high speed, large range and the like.

The application discloses a three-dimensional measurement method based on nonlinear cosine coding, and comprises the following steps: step one, generating N-step phase shift coding, constructing a wavelength-De Bruijn element mapping table, generating nonlinear cosine coding and nonlinear cosine component coding; step two, projecting phase shift stripes and nonlinear cosine coding stripes to a measured object frame by frame, acquiring a modulation pattern and decoding to obtain wrapped phase and nonlinear cosine components; step three, constructing an approximate phase, performing phase unwrapping on the wrapped phase to obtain a local continuous phase, and dividing the local continuous phase into local phases; step four, minimizing cosine component errors of the local phase regions to retrieve phase orders, thereby realizing phase unwrapping and obtaining error absolute phase; and step five, performing phase repair on the error absolute phase to obtain error-free absolute phase, and combining with structural light system parameters to reconstruct a three-dimensional model of an object. The application can realize high-precision phase unwrapping by using only a single frame pattern, and greatly improves the three-dimensional measurement efficiency.

The application discloses a rotating shaft rotating speed and radial runout detection method and system based on radar phase reconstruction, relates to the technical field of precision measurement, and comprises the following steps: obtaining a radar echo signal reflected by a target rotating shaft; performing signal processing based on the radar echo signal to obtain complex characteristic data in the distance dimension, performing angle separation, and obtaining a complex signal sequence after spatial separation; performing geometric circle fitting on the complex signal sequence on a complex plane to obtain a biased circle center; performing centering decoupling on the complex signal sequence to obtain a pure complex signal; performing phase extraction on the pure complex signal to obtain a naturally continuous absolute phase sequence under the Nyquist constraint condition of f_frame>2*f_rot; and performing spatial displacement mapping and parameter multi-dimensional calculation based on the absolute phase sequence to obtain the rotating speed and radial runout of the target rotating shaft. The application can realize the precision measurement of the absolute geometric quantity of the industrial rotating shaft rotating speed and radial runout.

The invention provides an antenna structure and electronic equipment. The antenna structure comprises n antenna units, n transmission lines and a signal line, the n antenna units are in one-to-one connection with the n transmission lines, and the n transmission lines are connected with the signal line after being combined at a combining point; wherein the n transmission lines are arranged according to the size sequence of the first phase values, the first phase values are values obtained by complementing 180 degrees by absolute phases of the transmission lines, and the difference value between the first phase value corresponding to the kth transmission line in the n transmission lines and the first phase value corresponding to the (k + 1) th transmission line is 180 degrees / n + / -180 degrees / 2n, the output impedance of the combining point is smaller than the characteristic impedance of the transmission line with the smallest characteristic impedance in the n transmission lines, n is larger than or equal to 2, and k is larger than or equal to 1 and smaller than n. According to the technical scheme, the antenna structure can be arranged in the electronic equipment with limited space, and good matching can be realized, so that the signal transmitting capability is improved.

The invention discloses a 5G module communication device based on a transparent antenna, relates to the technical field of 5G communication, solves the technical problems of interference of phase noise on high-frequency signal communication and interference of complex channels on low-frequency signals, and provides a 5G module communication device based on a transparent antenna through collaborative optimization of narrow loop bandwidth and charge pump current adjustment in combination with differential phase modulation. Adjacent symbol phase difference is used for bearing information, dependence on carrier absolute phase is avoided, phase noise interference is reduced, demodulation complexity is reduced, a dual-reference synchronization mechanism of zero-point signals and midpoint signals is introduced, a synchronization error is controlled within a sub-period range through counter forced reset and phase difference threshold judgment, and the synchronization failure rate is reduced. According to the method, the interference level and stable time interval sorting are combined, the frequency hopping sequence is dynamically adjusted, the number of communication interruptions of low-frequency signals in an industrial internet scene is reduced, transmission delay is reduced, and quantitative analysis of the idle channel stability is achieved based on double judgment of the signal intensity difference value and the stable time interval.

The invention belongs to the technical field of synthetic aperture radar interferometry, and particularly relates to a PS-InSAR multi-baseline time sequence phase unwrapping method based on uniform variable speed deformation assumption, which comprises the following steps of: preprocessing multi-temporal SAR data to obtain a time sequence difference interferogram, selecting a permanent scatterer PS point on the time sequence interferogram, and performing uniform variable speed deformation assumption on the selected permanent scatterer PS point; a second-order phase gradient constraint model is constructed on the time dimension under the assumption of uniform variable speed deformation, the integer fuzzy number gradient of the second-order phase gradient constraint model is solved by adopting a bidirectional time marching algorithm, and a global weighted L1 norm optimization problem about an absolute phase vector is constructed and solved based on the integer fuzzy number gradient. According to the method, the acceleration component in the earth surface deformation process is effectively described by establishing the second-order phase gradient constraint model, and the adaptability to complex time sequence deformation is improved.

The present application provides a kind of high-precision calibration method of projector overcoming nonlinear error, the present application adopts phase encoding technique, obtains absolute phase value by projecting gray code and sinusoidal stripe pattern.Hilbert transform is used to compensate phase error, reduce the error introduced by nonlinear factors of projector and camera.The feature points of calibration board are converted from camera pixel coordinate system to projector coordinate system by local homography matrix, further reduce the influence of nonlinear error on calibration accuracy.Finally, Zhang Zhengyou calibration method is used to calibrate the projector, and its internal and external parameters are obtained.This method can effectively improve the calibration accuracy and reduce the calibration difficulty.

This application relates to the interdisciplinary fields of optical precision measurement and artificial intelligence, and in particular to an artificial intelligence-based method for measuring absolute step error in a single exposure. By constructing a physical-guided artificial intelligence algorithm model, a virtual interferogram sequence of another wavelength is generated based on the interferogram sequence obtained by a single wavelength and a single exposure. The absolute phase of the surface under test is calculated by combining the principle of synthetic wavelength, and then the absolute step height is calculated. This solves the 2π phase ambiguity problem in traditional interferometry and realizes large-scale, high-precision measurement of absolute step height.

The invention provides a high-precision phase decoding method of a structured light three-dimensional measurement system, which belongs to the field of three-dimensional measurement, and comprises the following steps: constructing m groups of structured light patterns: constructing m groups of n-step phase shift sinusoidal grating coding patterns and corresponding Gray code grating coding patterns; the method comprises the following steps: respectively projecting m groups of n-step phase-shift sine structured light patterns to a measured object, projecting a Gray code structured light pattern, and shooting a scene after each projection to obtain a corresponding structured light projection image; performing one-time phase decoding calculation on each group of structured light projection images to obtain an absolute phase; performing probability consistent averaging on the m groups of absolute phases to obtain an optimized phase decoding result; the invention also provides a phase decoding system. Phase shift sine coding and Gray code structured light are adopted, and through grouping dislocation measurement and probability error compensation, phase errors caused by nonlinear response of each component, random dark current and the like are suppressed, and high-precision periodic phase decoding is obtained.

The application relates to the field of structured light three-dimensional measurement, and discloses a dual-frequency phase unwrapping method for encoding continuation, which cyclically projects absolute phase fringe sequence groups to an object, each absolute phase fringe sequence group comprises high-frequency three-step phase shift fringe images and first-step low-frequency phase shift fringe images and second-step low-frequency phase shift fringe images in low-frequency three-step phase shift fringe images, and absolute phase is calculated once per 1 or 2 phase shift fringe images corresponding to image signals. The total fringe number (N abs ) of the absolute phase fringe sequence group is 5, the absolute phase acquisition rate (f aacq ) is reduced from every 6 of the standard dual-frequency three-step phase shift method to an average of every 1.5, and the absolute phase acquisition rate is improved. In each fringe sequence group used for acquiring absolute phase, the high-frequency fringe group used for finally unwrapping absolute phase has a fringe number (N afspan ) of 4, and only two high-frequency phase shift fringe images are separated by one low-frequency phase shift fringe image, so that the measurement precision is maximally maintained.

The present invention provides a method and device for multi-cycle absolute phase calculation. The method collects first and second phase signals with different periods and processes them into non-orthogonal oblique trajectories. These trajectories are converted into complex form and then rotated and aligned by a set rotation angle. The rotated complex trajectories are then processed into discrete segments and interpolated to obtain the absolute phase. This method utilizes multi-cycle modulo phase signals to form non-orthogonal oblique trajectories, which are aligned with the rotation angle using complex representations. This achieves structural normalization, eliminates table lookup and inverse solution modules, and enables real-time angle recovery. The method is applicable to any period combination (including both coprime and non-coprime cases), offers high computational efficiency and accuracy, and can be directly deployed in an MCU / FPGA for real-time absolute phase calculation.

This application discloses a method, system, medium, and device for measuring the surface shape of a freeform surface mirror, relating to the field of optical precision measurement technology. It aims to solve the problem of poor accuracy in measuring the surface shape of freeform surface mirrors for head-up displays in existing technologies. This application first acquires fringe images reflected by the primary and secondary mirrors to obtain an absolute phase map for ray tracing. Next, it uses stereo matching of corresponding points to calculate initial depth data to eliminate ambiguity in normal-height coupling. Then, it constructs a variational fusion model for solving. The model introduces a depth fidelity term to suppress low-frequency surface distortion caused by the traditional gradient integral method, while introducing a gradient constraint term to smooth quantization noise in binocular vision, preserving the mirror's subtle features. Finally, by solving the model, high-precision three-dimensional surface shape data of the primary and secondary mirrors are obtained, improving the measurement accuracy of the surface shape.

This invention discloses a fringe phase retrieval method based on untangling theory-driven deep learning, belonging to the field of optical detection. The method includes: generating absolute phase labels based on a random number sequence; obtaining the original speckle image, wrapped phase labels, and wrapped count labels based on the absolute phase labels; constructing training and validation datasets; constructing a dual-task coupled network model based on a convolutional neural network and a composite loss function; training the dual-task coupled network model using the training dataset, validation dataset, and composite loss function; inputting the original fringe image to be processed into the trained dual-task coupled network model, and outputting the absolute phase result after fringe phase retrieval. This invention achieves unified end-to-end processing of speckle removal, fringe analysis, phase unwrapping, and phase retrieval, significantly improving the accuracy, robustness, and interpretability of the phase retrieval results under scenarios with noise, uneven illumination, complex backgrounds, and varying fringe density.

The invention relates to a phase unwrapping method and system based on double-phase signals, and the method comprises the steps: determining the phase difference between an original signal and an auxiliary signal, and achieving the purpose that in all pixels, when one signal is likely to be wound, the other signal is not likely to be wound; adding an auxiliary signal according to the phase difference between the original signal and the auxiliary signal; setting an upper limit and a lower limit of a winding early-warning phase; and when the original signal and the auxiliary signal exceed the winding early warning phase upper limit or lower limit, updating the value of the current pixel absolute phase through a difference algorithm to realize phase unwrapping. According to the method, due to the fact that an extra signal source is used, the influence of noise interference on winding point judgment is greatly reduced, and a certain recognition capability is achieved for signal mutation; secondly, real-time unwrapping can be realized without storing a large amount of historical data; finally, the algorithm does not need to store a large amount of historical data for judgment, the equation is simple, the requirement for computing power is very small, and the method can be operated in some small equipment.

The invention discloses an anti-interference detection method for an active electromagnetic regulation and control target, and the method comprises the steps: carrying out the modeling of an echo signal of an electromagnetic metasurface of a to-be-detected target according to a radar transmitting signal parameter, carrying out the carrier frequency removal and frequency modulation of the echo signal, and carrying out the phase unwrapping of the echo signal, and recovering an absolute phase; performing windowing segmentation on the unwrapped absolute phase, estimating the slope of each segment of phase data by using a least square method, and averaging the slope as a final slope estimation result; fitting a phase distribution linear function by using a slope estimation result to obtain a phase oblique line represented by the linear function; using a difference value between the phase oblique line and the absolute phase as a jump phase item; constructing a time domain phase compensation function, and multiplying the time domain phase compensation function by the echo signal to recover a hopping phase item modulated and changed by the electromagnetic metasurface to obtain a reconstructed signal; and performing matched filtering processing on the reconstructed signal to obtain an output signal.

The present invention provides a method for calibrating signal aliasing between bunches based on a cavity probe, comprising: obtaining an alias-free reference signal from a high-repetition-rate free electron laser device; extracting the signal waveform of each bunch and its measurement result from the alias-free reference signal; modeling a formula for the residual signal; obtaining a calibration result for the bunch based on the residual signal formula and a vector calibration algorithm according to the measurement result of the aliased signal waveform and the standard waveform of the previous bunch; using the next bunch as the current bunch and returning to the step of obtaining the calibration result; and continuing until all bunches are calibrated, at which point the calibration results for all bunches are obtained. The method of the present invention models and compensates for the amplitude and phase characteristics of the decay tails of adjacent bunches through a vector calibration algorithm, effectively eliminating the time-domain aliasing effect in the high-repetition-rate free electron laser device and reducing the absolute phase deviation of the beam arrival time measurement of the cavity probe to the femtosecond level.

This application discloses a method and system for verifying the uncertainty of an absolute phase noise standard using high- and low-frequency cross-verification. The method includes: determining the source of the maximum permissible error between a millimeter-wave relative noise standard and a low-frequency absolute phase noise standard; testing the low-frequency absolute phase noise standard and the millimeter-wave absolute phase noise standard based on the source of the maximum permissible error; and verifying the uncertainty of the millimeter-wave absolute phase noise standard based on the parameters obtained from the tests. This application solves the problem of the inability to verify the uncertainty of millimeter-wave absolute phase noise standard devices, thereby verifying the uncertainty of the millimeter-wave absolute phase noise standard.