473 results about "Interferometry" patented technology

The invention relates to the technical field of synthetic aperture radar interferometry, in particular to an intelligent sea reclamation site deformation monitoring system and method based on InSAR, and the system comprises a data collection module which is used for collecting a multi-temporal satellite-borne SAR image of a sea reclamation area; the data processing module is used for executing sub-pixel matching, orbit error correction, atmospheric delay correction and residual optimization; the model construction module is used for constructing a segmented orbit error model, a tide-humidity coupling model and a dynamic regression model; the verification feedback module is used for verifying leveling precision and dynamically adjusting model parameters; according to the method, by fusing terrain mutability, tide-humidity coupling and soil rheological characteristics of a reclamation scene, accurate correction of multi-source error distribution of orbit errors, atmospheric delay and creep noise is realized, and the problem of insufficient adaptability of a traditional method in reclamation area deformation monitoring is solved; and millimeter-level reliable data support can be provided for cofferdam safety, hydraulic reclamation consolidation and port engineering.

The invention discloses an optical time stretching sweep frequency interference measurement Doppler effect compensation method and device, and relates to the technical field of non-cooperative target absolute distance measurement. In order to solve the defect that the absolute distance measurement precision is reduced due to the fact that the Doppler effect cannot be efficiently suppressed in a complex environment in the prior art, the technical scheme provided by the invention comprises the following steps: generating a sweep frequency laser signal and splitting the sweep frequency laser signal to form measurement light, reference light and resampling light; performing time stretching processing on the reference light to obtain a chirp signal; performing interference on measurement light and the chirp signal to obtain a measurement interference signal; performing interference on the reference light and the resampling light to obtain a reference interference signal; performing cross-correlation processing on the measurement interference signal and the reference interference signal, and extracting an optical path difference; and carrying out distance calculation by combining the resampling data, and outputting a target distance after the Doppler effect is compensated. The method is suitable for optical measurement work for performing high-precision absolute distance measurement on a non-cooperative target in a tiny vibration or disturbance environment.

The invention discloses a time stretching sweep frequency interference high-precision distance measurement method and device based on double auxiliary interferometers, and relates to the technical field of non-cooperative target absolute distance measurement. In order to solve the technical defects that in the prior art, due to initial wavelength fluctuation of a light source and frequency sweeping nonlinearity, drift of a ranging result is large, and interference signals are interfered by zero-frequency noise, the technical scheme provided by the invention comprises the following steps: acquiring linear frequency modulation optical signals output by a common-source frequency sweeping laser; the signals are respectively transmitted to a measurement interferometer, an auxiliary interferometer and a resampling auxiliary interferometer to form a homologous three-interference structure; a dispersive medium is introduced through the reference arm, so that the reference light generates time stretching and interferes with the measurement light to form a chirp beat frequency signal; k-domain resampling and cross-correlation processing are carried out on the beat frequency signals, and target distance information is extracted. The method is suitable for high-precision and wide-range non-cooperative target absolute distance measurement work, and is especially suitable for the fields of laser radar three-dimensional modeling, precision industrial detection, robot calibration and the like.

The invention relates to the field of cable fault detection, in particular to a distribution cable fault positioning method based on electric signal analysis, which comprises the following steps of: determining a cable analysis state of each abnormal response point according to an interval monitoring execution index; determining whether to perform initial interference analysis or execute evaluation analysis according to the cable analysis state of the abnormal response point location; when initial interference analysis is carried out, whether interference compensation processing and range optimization processing are carried out on each abnormal response point location or not is determined according to the reference feature matching index; determining whether to perform channel filtering or not according to the interference effect evaluation index, and determining whether to perform compensation acquisition processing on each cable monitoring interval or not according to the interference compensation coefficient; and when the execution evaluation analysis is carried out, determining whether to carry out redundancy distribution prompt for each abnormal response point location according to the execution redundancy parameters. According to the method, the cable fault positioning efficiency is guaranteed, and meanwhile, the requirement for monitoring point arrangement is lowered.

The invention relates to the technical field of geological engineering, and discloses a geological safety risk dynamic assessment method based on multi-source data fusion, which comprises the following specific steps: step 1, collecting and standardizing multi-source geological data; 2, performing semantic fusion and conflict resolution on the geologic features; 3, constructing a dynamic risk assessment model; 4, risk situation real-time updating and early warning are carried out; the satellite remote sensing system in the first step adopts the synthetic aperture radar interference measurement technology, the spatial resolution is better than 3 meters, the revisit period is shorter than 7 days, and the earth surface deformation monitoring precision reaches the millimeter level. Through standardized processing and semantic fusion of the multi-source geological data, the problem of heterogeneous data integration is effectively solved, the data basic quality of risk assessment is improved, a space-time coupling neural network model is adopted, nonlinear features and space-time correlation characteristics of geological risk evolution are accurately captured, and prediction precision and timeliness are improved.

The invention discloses an InSAR (Interferometric Synthetic Aperture Radar) phase filtering method based on a plurality of interferograms, which comprises the following steps of: preprocessing acquired main and auxiliary SAR images to obtain the plurality of InSAR interferograms; dividing the plurality of InSAR interferograms into square interferogram patches along the azimuth direction and the distance direction; converting each interferogram patch from a spatial domain into a frequency domain signal, and constructing a corresponding frequency spectrum amplitude diagram; using a K-means clustering method to cluster and extract an initial low-pass filter in the spectrum amplitude diagram, and constructing a phase filter together with a Kaiser window function; the frequency domain signals of the interferogram plaques pass through a phase filter, the signal frequency band power is reserved, the noise at the high-frequency position is filtered out, meanwhile, the noise at the low-frequency position is filtered out through smoothing operation, and the filtered frequency domain signals are obtained; and the filtered frequency domain signals are converted to a spatial domain, filtered interferogram patches are obtained and spliced, and a filtered InSAR interferogram is obtained. The method is beneficial to popularization and promotion of the development of the current time sequence InSAR interferometry technology and the application in engineering.

The invention discloses a high-precision spectral interference signal demodulation method for micro distance measurement. The method comprises the steps of S1, interference spectrum shaping; measuring an interference spectrum and a reference spectrum; selecting a six-item combined cosine window as a primary function of an interference signal to obtain a shaped interference spectrum; s2, performing non-uniform Fourier transform to obtain a frequency spectrum of the target signal; s3, on the basis of a multi-spectral-line interpolation algorithm, interpolation is carried out on the window function to solve a fitting function, and a center frequency k is obtained; and S4, outputting a result. And solving and outputting an optical path difference d. According to the method, a six-item cosine combination window is selected as a primary function of an interference signal, and the problem that the accuracy of signal extraction is influenced by mutual superposition of side lobes and even main lobes of a direct current item and a solved frequency item is solved; an interference spectrum is processed by using a fast non-uniform Fourier transform algorithm, accuracy can still be kept under the conditions that the distance to be measured is increased and sampling is gradually sparse, and the problem of resampling deviation caused by a traditional interpolation method can be solved.

Various optical systems for use in a light pulse atomic interferometer (LPAI)-based one-, two-, or three-axis accelerometer or gyroscope are disclosed. As an LPAI accelerometer or gyroscope may employ many different laser beams to implement the LPAI functionality, ways of combining these different laser beams to thereby simplify the optical systems are desired. The cooling laser beam portion of the optical system may be simplified using one or more reflective grating chips. The Raman laser beam optics may be simplified using combiners and separators. For LPAI systems sensing along three axes, various optical switching schemes may be employed, including ones that generate variable data-rates with a primary sensing axis having a higher data-rate than the secondary sensing axes. Further, by combining various laser beams in a time-multiplexed manner, the number of optical fiber tethers to a sensor head may be reduced.

The invention discloses a space-air-ground collaborative rock-soil landslide monitoring and early warning system, which relates to the technical field of disaster monitoring and early warning and comprises an air remote sensing monitoring module, a ground sensing module, a data communication module, a multi-source information fusion module and an intelligent early warning decision module. The aerial remote sensing monitoring module is used for collecting aerial image data based on the unmanned aerial vehicle; the ground sensing module is used for collecting ground sensing data; the multi-source information fusion module is used for fusing and aligning aerial image data, ground sensing data and geological model multi-dimensional information, extracting surface crack morphological characteristics by adopting a deep learning algorithm, analyzing a deformation time sequence generated by radar interferometry and identifying an abnormal motion mode; the intelligent early warning decision module is used for analyzing the landslide evolution stage and simulating the geologic body deformation process and conducting early warning decision, the problem of signal blind areas of a traditional monitoring system in extreme landforms can be effectively solved, and total factor analysis and advanced early warning of the disaster evolution process are achieved.

The invention provides a three-dimensional flow velocity field inversion method and system based on coherence-assisted SAR adaptive offset tracking, and a storage medium, so as to improve the problem of decoherence caused by time heterogeneity in a synthetic aperture radar interferometry (InSAR) technology, and relates to the technical field of electric power engineering geological disaster monitoring. The method comprises the following steps: establishing a space-time baseline network between SAR images; obtaining coherence data after geocoding; selecting a pair of SAR images from the space-time baseline network as a reference unit, calculating an offset result through a pixel offset tracking technology for the reference unit, and determining an optimal matching window parameter of the reference unit; establishing a mapping function between coherence and optimal matching window parameters; according to the established mapping function, calculating an optimal matching window parameter of each remaining SAR image pair; and in combination with the line-of-sight average deformation rate fields of the ascending and descending rails, inverting a surface three-dimensional flow velocity deformation field of the target area through a geometric vector decomposition model.

The invention relates to the technical field of optical detection, and discloses an object surface three-dimensional topography measurement method based on optical interference, which comprises the following steps: acquiring a mixed time domain interference signal sequence in an axial scanning process; extracting seed pixels and constructing a spatial topology connectivity feature matrix; introducing fractional Fourier transform, and constructing a joint decoupling objective function containing a frequency domain nonlinear phase distortion evaluation index and a time domain physical invariant evaluation index; executing multi-stage optimization for the seed pixels, and locking a global optimal rotation angle; array self-adaptive decoupling is executed in combination with the spatial topology connectivity feature matrix, and an optimal rotation angle matrix is generated; and performing signal decoupling and reconstruction on the mixed signal, and extracting the absolute surface height of each pixel point to generate three-dimensional shape data. According to the invention, through multi-dimensional joint decoupling and spatial prior constraint, the problem of phase decoupling caused by film interference aliasing is solved, and the calculation overhead of a large-pixel array is reduced while the measurement precision is improved.

The invention relates to a multi-parameter estimation algorithm combining a disturbance quantification model and a rooting method in interference measurement. In order to solve the problems that in the prior art, the disturbance degree of a sequence is difficult to quantify, and harmonic key parameters are influenced by spectrum leakage, the invention provides the following innovative scheme: firstly, a sequence multi-classification measurement entropy quantification model is constructed, and quantitative evaluation of the signal noise degree is realized; secondly, through a Hankel matrix construction and rooting parameter estimation method, realizing accurate estimation of the harmonic frequency of the real-value signal; meanwhile, an amplitude correction algorithm based on window function characteristics is designed, and the signal sampling condition is effectively judged; and finally, through matrix weighting operation of a phase demodulation function, efficient reconstruction of an optical surface shape is realized, the problems of spectrum leakage and disturbance quantification in a traditional method are solved, and the method has relatively high measurement precision.

According to the single-frame high-quality shearing speckle interference phase extraction method and device, the quality of the obtained phase is comparable to that of a traditional multi-frame phase solution algorithm, and single-frame high-quality phase extraction of shearing speckle interference is completed. The method comprises the following steps: (1) making a data set; (2) constructing a neural network; (3) neural network training; (4) detecting the detected piece: when the detected piece is static, carrying out N-step phase shift method shooting to obtain N frames of speckle interferograms when the detected piece is static; applying an external force to the measured piece, and recording light intensity information by using a camera to obtain a frame of interferogram when the measured piece is deformed; (5) single-frame phase extraction: phase extraction is carried out according to an N + 1 time phase shift method, and on the basis of N frames of phase shift interferograms when the measured piece is static, phase extraction is carried out by using one frame of interferograms after the measured piece is deformed, so that low-quality phase distribution is obtained; and (6) phase repairing.

A plateau mountain area road slope geological disaster automatic identification method fusing multiple data comprises the following steps: S1, acquiring multi-source heterogeneous data of a target slope area, including a time sequence satellite optical image, synthetic aperture radar interferometry (InSAR) deformation data, laser radar (LiDAR) point cloud data, meteorological and hydrological data and basic geological data, and generating fusion data; s2, constructing a space-time registration module, unifying the multi-source data obtained in the S1, establishing a unified space-time coordinate system for the multi-source data, and generating fusion data; and S3, processing synthetic aperture radar interferometry (InSAR) deformation data through a freeze-thaw cycle noise compensation model, and eliminating deformation noise caused by seasonal frost heaving and thaw collapse. According to the plateau slope disaster identification method, the plateau freeze-thaw compensation model is combined with a multi-modal dynamic decision-making mechanism, and physical mechanism complementation of InSAR and LiDAR is adopted, so that'earth surface deformation-rock mass structure 'two-dimensional verification is realized, and multi-data fusion is realized, and therefore, the automatic identification precision of plateau slope disasters is improved.

The invention discloses a spectral interference system resolution improving method and system, and the method comprises the steps: building an ISE-Net end-to-end deep neural network model, enabling the convolution kernel size of an efficient channel attention module of the ISE-Net end-to-end deep neural network model to be adaptively determined according to the number of input channels, and constructing a mapping relation between narrowband and broadband interference signals; and generating an ideal narrowband signal and a double-bandwidth target signal according to a spectral interference physical formula, defining a loss function by minimizing deviation between model output and the target signal, updating parameters and dynamically adjusting a learning rate by using an AdamW optimizer until model loss is converged, and completing data generation and training. An input narrowband signal horizontal axis is converted to a corresponding frequency domain axis, and is subjected to time shifting and intensity scaling preprocessing to adapt to the model. A signal processing flow suitable for a single / multi-layer structure is constructed, a bandwidth expansion signal is obtained through decomposition, expansion and reconstruction, and the resolution of a spectrum interference system is improved. The method has the advantages of high calculation efficiency, high generalization and flexible deployment.

The invention relates to the technical field of synthetic aperture radar interferometry (InSAR) and deep learning, and discloses a CNN-BiGRU landslide displacement prediction method based on InSAR deformation spatial-temporal feature fusion. The method comprises the following steps: firstly, acquiring landslide area time sequence deformation displacement by utilizing an SBAS-InSAR technology, decomposing the displacement into a trend term, a season term and a noise component by adopting variational mode decomposition (VMD), fitting and predicting the trend term and a segmented polynomial through RNN, converting a one-dimensional time sequence into a time-frequency image by the season term through a Gramb angle field (GADF), extracting spatial features by combining the CNN and extracting time sequence features by a BiGRU, and calculating the landslide area time sequence deformation displacement according to the time-frequency image. Multi-modal fusion prediction is realized; and finally combining the trend term and the season term to obtain total displacement prediction. Experiments prove that RMSE, MAE and Rindexes of the method in seasonal item and total displacement prediction are all superior to those of comparison models such as BiGRU and BiLSTM, and prediction precision and reliability are remarkably improved.

The invention relates to a method for measuring the coherence length of a Shell model correlation structure light beam, which belongs to the field of laser space coherence measurement, and comprises the following steps: S1, calculating the coherence lengths # imgabs0 # and # imgabs1 # in x and y directions by using the analytic relationship between the coherence length of the Shell model correlation structure light beam and the spatial coherence modulus; s2, a double-aperture mask is arranged on a light beam shaping transmission path of the laser processing system, the aperture positions are symmetrical, the distance d is adjustable, and after light beams are focused, intensity signals # imgabs2 are collected at a focal plane detector; and S3, extracting an intensity signal # imgabs3 # to obtain a double-aperture interferogram, performing Fourier transform on the interferogram, establishing a corresponding relation between a low-frequency component in a frequency spectrum and a characteristic frequency of an aperture spacing d, and calculating to obtain a spatial coherence modulus # imgabs4 #. According to the invention, based on partially coherent light dual-aperture interference and Fourier spectrum analysis, a direct analytical relationship between the spatial coherence degree and the coherence length is established, and a new way is provided for beam quality control in laser processing.

The invention discloses a variable view field Linnik interference microscopic system and a measurement method thereof, and belongs to the field of laser measurement instruments, and a variable diaphragm is introduced into a reference arm of an interference system to realize matching of objective lenses of different test arms, so that light field spatial correlation under speckle illumination is maintained; meanwhile, a light source system with a delay line structure is adopted to accurately compensate the optical path difference introduced by the asymmetric objective lens configuration, so that the acquisition of a high-contrast interference pattern is realized. The method can effectively improve the quality of an interference image, has a depth selection function, and is suitable for dynamic phase imaging in different view field ranges. The technical scheme of the invention shows good imaging effect and adaptability in the aspects of dynamic imaging and depth layering.

A photonic integrated circuit including at least one integrated optical gain section having a peak gain at a first frequency; and at least one nonlinear sub-circuit which is coupled to the optical gain section either evanescently or through edge coupling, wherein the nonlinear sub-circuit further comprises at least one nonlinear component comprising at least one of a waveguide or a resonator comprising second-order nonlinearity enabling generation of frequency components at least one octave below or above the first frequency, and the nonlinear sub-circuit is configured to provide at least one of nonlinear interferometry wherein the interferometer output depends on the input intensity to the nonlinear sub-circuit, or spectral broadening by extending the spectrum outside the gain spectrum of the gain section.

The present invention relates to an optical system and a method for chromatic confocal spectral-domain optical coherence tomography or for chromatic confocal two-beam interferometry. The optical system comprises a multispectral light source unit configured to generate a plurality of spatially coherent multispectral light beams with spectra having a respective centroid wavenumbers, an achromatic focusing unit configured such that in at least a paraxial region around a common point located on an optical axis at the output of the achromatic focusing unit, the wavefronts of the respective spatially coherent multispectral light beams have different radii of curvatures, a chromatic confocal dual-beam interferometer having an non-zero optical path difference arranged downstream of the multispectral light source unit and a detection unit for detecting light returned from the dual-beam interferometer. The reference arm of the double-beam interferometer is configured to be achromatic and the object arm to have chromatic depth slitting of foci. In the reference arm, a plurality of depth separated reference light spots are formed. In the object arm, a plurality of at least partially colinear and overlapping multispectral stretches of diffraction limited light spots extended in a depth direction of the object arm is formed. The light reflected by a current sharply focused diffraction limited object light spot of each of the multispectral stretches of diffraction limited light spots is combined with a respective reference light spot, is confocally discriminated by a confocal discrimination unit of the detection unit and subsequently detected by at least one spectrometer, evaluation dual-beam interferometer or fast detector detects the confocally discriminated light.

The invention relates to a high-precision multi-surface wavelength tuning interference measurement signal processing method. The core of the method is to solve the problem of dissociation of superposed interference signals and overcome the frequency spectrum fence effect. The patent process comprises the following steps: constructing a dissociation framework based on an iteration vector and a time delay virtual detection point; optimizing an iteration process by using an approximate Newton method; designing a double judgment dissociation criterion and orthogonally outputting a dissociation result; performing frequency spectrum fine segmentation analysis and phase demodulation function extraction on the dissociation signal to realize high-precision solution of harmonic frequency and phase; and the dissociation quality can be evaluated by using a correlation coefficient quantification method. The method can effectively separate multi-surface interference superposition signals and accurately reconstruct key parameters, is obviously superior to a traditional method (such as FFT), and improves the performance by about two orders of magnitude. Experiments prove that the surface shape error is controlled to be 10e <-3 > magnitude, the frequency precision reaches 10e <-4 > magnitude, and the method has excellent robustness and wide applicability and is suitable for high-precision optical element detection.

The invention discloses a cross-sensor long-time-sequence InSAR deformation monitoring method and device, a medium and a product, and relates to the field of synthetic aperture radar interferometry, the method comprises the following steps: obtaining image data sets of a plurality of SAR sensors in a monitoring area, and sequentially carrying out differential interference and time sequence deformation calculation to obtain an LOS direction deformation result; geocoding all results to unify a coordinate system; screening high-coherence point targets and constructing an observation geometry unified analysis model; time information is obtained by combining the images, and a long-time-sequence earth surface deformation resolving function model after observation geometric correction is established; and further introducing a truncated singular value decomposition operator, constructing a cross-sensor long-time-sequence deformation resolving analysis model, and finally resolving to obtain a high-precision and long-time-span earth surface deformation product in the monitoring area. According to the method, the problems of rank deficiency and solution failure caused by time shortage and observation geometric difference in multi-platform InSAR data joint solution are effectively solved, and the precision and applicability of long-time-sequence deformation monitoring are remarkably improved.

A system for automatically focusing ("autofocusing") a microscope during an inner limiting membrane (ILM) peeling maneuver is configured to output low-coherence infrared (IR) light toward the eye during the maneuver. The system includes an interferometer that senses an axial distance between the microscope and ILM and outputs distance signals indicative of the sensed axial distance. An electronic control unit (ECU) is in communication with motor-driven lenses of the microscope and with an IR light source of the interferometer. Execution of the instructions causes the ECU to receive the distance signals from the interferometer. In response to the distance signals, the ECU transmits a focus control signal to the lens(es) to thereby resolve the ILM with a desired depth-of-field. The ECU automatically adjusts a focus level of the microscope on the ILM to accommodate for respiration-related movements of the patient.

The invention provides a forest vertical structure information inversion method and system based on radar interferometry, and the method comprises the steps: carrying out the small-view processing of high-resolution SAR interferometry data with a space baseline, calculating the small-view InSAR phase height, extracting the statistical distribution of the small-view interferometry phase height in a set space window, and carrying out the calculation of the small-view interferometry phase height. Generating a small-looks interferometric phase height histogram; establishing an under-forest ground elevation regression estimation model based on the statistical characteristics of the small-looks interferometric phase height histogram, and determining model parameters to invert the terrain; and two canopy top indexes are extracted, two index results are fused by setting a threshold value, and final forest vertical structure information is generated. The method has the advantages that more canopy internal and under-forest information can be captured only by using single-baseline and single-polarization radar interference data, and the sensitivity to a forest vertical structure is improved; and the forest vertical section, the tree height and the terrain can be synchronously inverted.

Provided are a silicon-based tunable filter, laser and an optical module. The tunable laser comprises a semiconductor optical amplifier and a silicon photonic integrated chip, wherein a first coupler, a phase regulator and a tunable filter are provided on the silicon photonic integrated chip; the tunable filter comprises a flat-top band-pass filter structure, a Mach-Zehnder interferometry (MZI) structure and a micro ring resonation (MRR) structure, which are cascaded; gain light emitted by the semiconductor optical amplifier is coupled to the silicon photonic integrated chip by means of the first coupler, and a narrowband filtered optical signal is output by means of the tunable filter; and the phase of the gain light is regulated by means of the phase regulator so as to output single-peak narrowband laser light with a tunable target wavelength.

The present invention discloses a refractive index sensor and measurement method based on a grating-prism system, belonging to the field of optical interferometry. The sensor comprises a sequentially arranged parallel light, a plane grating, a sample cell, a converging component, and a spectral analysis system. The sample cell is provided with a prism and a sample to be measured. The parallel light propagates through the plane grating, which splits the parallel light into multiple sub-beams. The sub-beams are then converged by the converging component and arrive at the spectral analysis system for refractive index measurement. The sensor uses a plane grating to periodically block the incident parallel light, splitting it into sub-beams. Each level of diffraction light in each sub-beam is considered a waveband. After the sub-beams propagate through the prism and the sample to be measured, the same-order sub-bands of any two adjacent sub-beams have the same phase delay difference. By selecting the same-order sub-bands to construct multi-beam interferometry, the sensor can simultaneously achieve low-cost, high-sensitivity, and high-resolution refractive index measurement.

The invention relates to an automatic correction method and device for an aspheric mirror interference measurement installation and adjustment error, which can realize automatic, accurate and rapid automatic correction of the installation and adjustment error. The method comprises the following steps: (1) building a virtual interferometer; (2) making a data set; (3) neural network construction and training: constructing a classification neural network, inputting an interference pattern and outputting an installation and adjustment error category, and performing network training by using the data set obtained in the step (2), so that the neural network has the installation and adjustment error detection capability; (4) assembly and adjustment error prediction: obtaining an interferogram under the current assembly and adjustment in an actual interference light path, inputting the interferogram into the trained neural network, and completing the prediction of an assembly and adjustment error category; (5) correcting the installation and adjustment error: according to an installation and adjustment error prediction result obtained in the step (4), controlling a corresponding mechanical part to correct the installation and adjustment error; (6) if the neural network detects that the installation and adjustment error does not meet the requirement, executing the step (4); otherwise, executing the step (7); and (7) ending.

A variable wavelength interferometer operates in the back focal plane of the objective and produces a narrow band illumination beam with a peak wavelength that is varied over a range of wavelengths. An interferometric objective directs light to the sample and a reference surface and recombines the reflected light to produce interference. At least one polarizer generates one or more polarization states of the sample illumination and of the reference illumination. One or more path length differences between the sample and reference illumination is produced. At least one camera captures images of the interference illumination at a back focal plane of the interferometric objective for each combination of peak wavelength and polarization state. The interferometric data at one or more pixels of the camera are used to extract structural information for the sample.

A surface deformation monitoring method and systems based on time-series InSAR (TS-InSAR) are provided. The method includes acquiring Synthetic Aperture Radar (SAR) data; performing differential interferometry; performing a robust two-tier multi-temporal InSAR method for detection of Persistent Scatterer (PS) and Distributed Scatterer (DS) candidates to acquire time series data for surface deformation monitoring; performing a variational mode decomposition (VMD) method to decompose TS-InSAR data into a plurality of components; reconstructing time series data; performing a gated recurrent unit (GRU) method; extracting trend of surface deformation; and performing continuous large-scale deformation monitoring. The InSAR-based deformation monitoring method integrates VMD and GRU, offering significant improvements in robustness and accuracy over the existing methods.

The invention relates to the technical field of optical interference measurement, in particular to a synchronous wavelength phase-shifting interference measurement system. According to the scheme, a laser set outputs multiple narrow-linewidth light beams with nm-level wavelength spacing, and the multiple narrow-linewidth light beams are combined through a wavelength division multiplexer and then enter an interference light path to generate multi-wavelength interference fringes. The metasurface achieves separation of interference fringes of all wavelengths through a sub-wavelength structure array, a detector synchronously captures light intensity data of the interference fringes of all the wavelengths in a single frame mode, and then phase distribution can be directly calculated through single-frame multi-wavelength light intensity. According to the system, mechanical phase shifting and polarization control assemblies are eliminated, the defects that a traditional wavelength phase shifting interference measurement technology is poor in environmental adaptability and a traditional synchronous phase shifting technology has polarization errors are overcome, and a high-precision and high-environmental-adaptability dynamic measurement scheme is provided for optical manufacturing.