23 results about "Wavefront curvature" patented technology

Disclosed in the present invention are: a far-field simulator that simulates a beam in a form of propagation from a remote point; and an optical test system including same. The far-field simulator comprises: a beam splitter configured to split an incident beam into a first beam and a second beam; a first far-field simulation unit configured to increase the curvature of a wavefront of the first beam passing through the beam splitter to simulate the first beam in a form of propagation from a remote point; and a second far-field simulation unit configured to increase the curvature of a wavefront of the second beam passing through the beam splitter to simulate the second beam in a form of propagation from a remote point, wherein the first beam emitted through the first far-field simulation unit is formed to have a greater diameter than the diameter of the second beam emitted through the second far-field simulation unit.

The invention discloses a casting layer stress prediction method and system based on an artificial neural network and a storage medium, and the method comprises the steps: taking a silicon wafer as an electroforming substrate, polishing one surface of the electroforming substrate, and arranging a conductive layer on the other surface; an electroforming tank, a collimation light source and a wavefront sensor are configured, and the relative positions of the collimation light source, the wavefront sensor and the electroforming tank are adjusted, so that a light beam of the collimation light source is reflected by the polished surface of the silicon wafer to enter the wavefront sensor; performing electroforming in an electroforming tank by adopting direct current or pulse current; electroforming process data and laser wavefront curvature radius are acquired through a data acquisition module; calculating a stress value according to the laser wavefront curvature radius, and converting stress value data and electroforming process data into a neural network adaptive format; selecting a network type, an activation function and a hyper-parameter, and training an artificial neural network model to fit a nonlinear relationship between an electroforming parameter and a stress value; and stress prediction: inputting the electroforming parameters to the artificial neural network model, and outputting a predicted casting layer stress value.

The present application provides an endoscopic optical system, an endoscope, and an endoscopic system, wherein the endoscopic optical system includes an aperture and a lens assembly; the lens assembly includes a target lens, and the target surface of the target lens is coated with a filter film layer; wherein the difference between the curvature of the target surface and the incident wavefront curvature of each field of view principal ray on the target surface is within a set curvature range, so that the incident angle of each field of view principal ray on the target surface of the target lens is less than or equal to the set angle. The present application effectively eliminates or reduces the adverse effects of wavelength drift while reducing the use of filters. Therefore, while reducing wavelength drift, the present application also has a simple structure and low cost for the endoscopic optical system.

This application discloses a focusing noise optimization method, apparatus, storage medium, and product, relating to the field of interferometric noise optimization technology. The focusing noise optimization method includes: acquiring an initial interferometric image containing multiple types of focusing noise and inputting it into a preset noise error correlation model to obtain the noise influence coefficients of each type of focusing noise. The noise error correlation model is obtained by training a model to be trained based on interferometric image samples, which include multiple types of focusing noise and actual focusing errors. Based on the noise influence coefficients, a corresponding denoising algorithm is used to remove the focusing noise of the appropriate type. This application enables the model to be trained to learn the relationship between various types of noise and focusing errors, thereby determining the influence coefficients of each type of focusing noise on the focusing errors. Based on the noise influence coefficients, the corresponding types of focusing noise are selectively removed to avoid affecting the wavefront curvature extraction accuracy, thereby improving the focusing accuracy of the wavefront curvature interferometry method.

The invention relates to the technical field of curvature radius detection, and discloses a large-aperture spliced mirror curvature radius detection system based on a photon lead, and the system comprises an integrated optical waveguide interference array which is used for being placed in the center of a system region and transmitting two beams of similar spherical waves to a detected mirror surface; the frequency carrier module is used for modulating interference fringes formed by the light beams reflected by the measured mirror surface so as to obtain the actual wavefront of the system; the signal processing module is used for performing Fourier transform on the modulated interference fringes to obtain the wavefront curvature of the system; the laser tracker is used for determining the positions of input and output light spots; and the curvature calculation module is used for obtaining the accurate curvature radius of the measured mirror surface. According to the invention, an integrated optical waveguide interference array is adopted to emit spherical waves, so that the assembly error of discrete optical elements is reduced, and the system stability is improved; the interference fringes are modulated through frequency carrier waves, and the Fourier transform algorithm is combined, so that the analysis precision of the wavefront curvature is remarkably improved.

The invention relates to the technical field of active optics, and particularly provides a time sequence filtering-based wave-front correction method for a patrol telescope, which comprises the following steps of: firstly, acquiring time sequence wave-front data of the telescope through a wave-front curvature sensor, decomposing the time sequence wave-front data in a spatial domain through a Zernike polynomial, forming a time sequence coefficient sequence by coefficients of each item of the Zernike polynomial in a time domain, and correcting the time sequence coefficient sequence according to the time sequence coefficient sequence; and carrying out frequency domain analysis on each time sequence coefficient sequence, calculating a power spectrum, identifying static aberration by using a Greenwood frequency as a threshold value, filtering dynamic aberration, and then carrying out wavefront correction. According to the method, Zernike polynomial decomposition and frequency domain filtering are combined, high-frequency disturbance introduced by atmospheric turbulence is effectively separated and filtered out, and low-frequency aberration wavefront correction is accurately achieved through active optics.

A method for displaying virtual content to a user, the method includes determining an accommodation of the user's eyes. The method also includes delivering, through a first waveguide of a stack of waveguides, light rays having a first wavefront curvature based at least in part on the determined accommodation, wherein the first wavefront curvature corresponds to a focal distance of the determined accommodation. The method further includes delivering, through a second waveguide of the stack of waveguides, light rays having a second wavefront curvature, the second wavefront curvature associated with a predetermined margin of the focal distance of the determined accommodation.

This invention relates to a two-dimensional air-varying filtering method for precise compensation of wavefront curvature in PFA (Position Frame Analysis) of a mobile platform. It integrates three-dimensional acceleration into the PFA algorithm's imaging process for coarse-focused PFA imaging of the mobile platform. Based on this, a two-dimensional air-varying filter is constructed, and a block-based approach is used to perform two-dimensional air-varying filtering on the coarse-focused PFA image to achieve coarse correction of wavefront curvature. Finally, a fine-focused PFA image is obtained through geometric deformation correction. Compared to existing technologies, this invention ensures no geometric deformation in the image while maintaining good focusing performance, thus exhibiting higher imaging performance.

The present application relates to the technical field of SAR imaging, and provides a curve trajectory SAR imaging method and device of spatial time-varying acceleration, which is aimed at a high-speed maneuverable radar platform carrying a synthetic aperture radar, constructs a SAR imaging echo model based on spatial time-varying acceleration, and acquires a real slant range history between the high-speed maneuverable radar platform and a target object, acquires a to-be-processed echo signal in a spatial wave number domain according to the real slant range history, and performs non-space-variant motion and distance cell migration compensation on the to-be-processed echo signal according to a preset Deramp compensation function constructed by a motion error. The echo signal is subjected to interpolation processing according to a rotation interpolation kernel function determined by a real motion trajectory, to obtain an interpolated echo signal, and a coarse-focusing SAR image is acquired according to the interpolated echo signal. A target SAR image is obtained by performing wavefront curvature phase compensation on the coarse-focusing SAR image according to a wavefront curvature phase compensation factor determined by the real motion trajectory.

The invention discloses a reservoir dam body leakage vibration monitoring method based on distributed sound sensing, and relates to the technical field of dam body safety monitoring, and the method comprises the following steps: obtaining a unified time baseline, constructing a phase reference field, injecting calibration pulses on the basis of the phase reference field, inverting a multi-medium sound velocity tensor, and forming a real-time refraction map; a distributed sensing node arrival angle sequence is obtained under the constraint of a real-time refraction atlas, a wavefront curvature field is solved, an energy anomaly convergence kernel is locked, and a space positioning basis is established for leakage signal feature extraction. According to the invention, a closed loop chain from modeling, purification and positioning to regulation and control is constructed, high-precision leakage identification, dynamic extinguishing of false hot spots and enhancement of real signals are realized through a refraction spectrum, coherent reconstruction and digital twinning, the sensitivity, accuracy and regulation and control capability of dam body leakage monitoring are remarkably improved, and conversion from passive identification to active control is realized.

This invention discloses a segmentation processing method and system for sand and gravel aggregate images, relating to the field of image processing technology. The method includes: acquiring the original image of the sand and gravel aggregate and converting it into a two-dimensional grayscale pixel matrix; constructing a multi-layered feature excitation field, with each layer corresponding to a preset scale factor; injecting the two-dimensional grayscale pixel matrix as an initial excitation source into all layers in parallel, generating an initial set of oscillating wavefronts with different wavefront curvatures within each layer; independently calculating the propagation path, energy attenuation coefficient, and encounter interference phase of each wavefront within each layer to form a dynamic oscillating wavefield; detecting the pixel coordinates where the wavefront energy in each layer first drops to zero as a set of wavefront annihilation points; performing spatial coordinate superposition and XOR logic operations on the wavefront annihilation point sets of all layers to generate a pixel cloud with stable boundaries; and marking the connected components of the pixel cloud to achieve pixel-level segmentation of aggregate particles, outputting independent aggregate particle image regions.

This application relates to the field of equipment testing technology, and provides a license plate recognition testing method, a license plate recognition testing device, an electronic device, and a product. The license plate recognition testing method includes: when a test scene sequence is played using a microdisplay, converting the emitted light from the microdisplay into collimated light using a collimating optical component; the collimated light is used to enable the camera under test to obtain equivalent long-distance imaging conditions; the test scene sequence includes at least one scene frame, and the scene frame includes at least a license plate image; when the camera under test obtains the equivalent long-distance imaging conditions, changing the wavefront curvature of the collimating optical component to obtain an equivalent target distance; driving the camera under test to automatically focus at the equivalent target distance, performing license plate recognition on the scene frame, and obtaining a license plate recognition result. This application can simulate the optical imaging conditions of a real road in a limited laboratory space and realistically trigger the automatic focusing of the camera under test.

An optical system for use in augmented reality glasses is presented. The optical system defines an eyebox and comprises a lens unit comprising an integral structure formed by a lens having a predetermined wavefront curvature, and a see-through optical combiner embedded inside the lens such that the see-through optical combiner is located in an inner part of the lens being enclosed by opposite lens segments of, respectively, front and rear parts of the lens. The see-through optical combiner comprises a plurality of partially-transparent reflectors arranged in a spaced-apart parallel relationship along the inner part and exposed to interaction with input light propagating along a first axis through the inner part of the lens and being indicative of image being projected with a certain exit pupil. The partially-transparent reflectors are inclined with respect to the first axis, such that the reflectors successively interact with the input light, and form light reflections therefrom, thereby providing replication of the exit pupil along a first dimension of the eyebox while maintaining the wavefront curvature of the lens.

The present application relates to a kind of based on the digital detection method of pulse focal spot of variable sampling matrix, this method is completed by variable sampling matrix to replace digital frequency domain algorithm to three-dimensional pulse far field light spot digital detection;For the three-dimensional space-time pulse signal generated by pulsed light source, the wavefront curvature of incident pulse is obtained by wavefront sensor, combined with the digital three-dimensional complex amplitude matrix of pulsed light parameter, then the far field focal spot calculation is completed by variable sampling matrix modification sampling boundary condition, and the focal spot distribution of the arbitrary sampling parameter of three-dimensional space-time focal spot is obtained.The present application can effectively extend the near field or far field transmission calculation range of the surface distribution of the measured pulse signal, avoid the signal aliasing caused by the calculation window of low space bandwidth product, improve the sampling resolution while reducing the required time of calculation, and can obtain the high sampling resolution synchronized with the upper limit of hardware device calculation.

The invention provides an RCS near-far field transformation method and system based on synthetic aperture imaging, and belongs to the technical field of communication radars. A strict RCS (radar cross section) near-far field transformation algorithm is established by utilizing the progressive property of cylindrical wave expansion of a Hankel function in a cylindrical coordinate system and combining near-field scattering data, so that the problem of errors caused by wavefront curvature in near-field measurement is solved, and the echo signal intensity of a to-be-measured target under a far-field condition can be accurately obtained. Based on multi-angle radar signal fusion and splicing of near-far field transformation results, a high-resolution scattering characteristic image of a to-be-measured target can be synthesized. According to the method, the distance coupling effect in near-field measurement is eliminated while the detail features of the target are reserved, so that the electromagnetic scattering behavior of the target under the far-field condition is reflected more truly.

Disclosed is a far-field simulator for simulating a beam as having been propagated from a remote point. The far-field simulator comprises: a beam splitter configured to split an incident beam into a first beam and a second beam; a far-field simulation unit which is disposed on the optical path of the first beam that has passed through the beam splitter and configured to increase the curvature of the wavefront of the passing first beam, and that simulates the first beam as having been propagated from a remote point; an interference pattern acquisition unit formed to be struck by the first beam that has passed through the far-field simulation unit and the second beam split by the beam splitter, and configured to acquire interference patterns of the first and second beams; and an alignment unit configured to align the far-field simulation unit, so that the first beam that has passed through the far-field simulation unit has a flatness in a predetermined range, on the basis of the interference patterns acquired by the interference pattern acquisition unit.

An optical system for use in augmented reality glasses is presented. The optical system defines an eyebox and comprises a lens unit comprising an integral structure formed by a lens and a see-through optical combiner embedded inside the lens being located in an inner part of the lens and enclosed by opposite lens segments of front and rear parts of the lens. The combiner comprises partially-transparent reflectors arranged in a spaced-apart relationship along the inner part and exposed to interaction with input light propagating along a first axis through the inner part of the lens and being indicative of image being projected with a certain exit pupil. The reflectors are inclined with respect to the first axis, to successively interact with the input light and form light reflections providing replication of the exit pupil along a first dimension of the eyebox while maintaining the wavefront curvature of the lens.

The application discloses a large-aperture telescope wavefront curvature sensing method, comprising the following steps: obtaining a defocus star point image of single exposure through a sensor defocus; obtaining a phase distribution of the defocus star point image of single exposure; applying defocus to the defocus star point image of single exposure in a reverse direction to obtain a reverse defocus star point image; and obtaining wavefront curvature reconstruction through the phase distribution of the defocus star point image of single exposure and the reverse defocus star point image, so as to realize single-exposure curvature sensing. The application also provides corresponding electronic equipment and a computer readable storage medium.

The invention discloses a focusing noise optimization method and device, a storage medium and a product, and relates to the technical field of interference noise optimization, and the focusing noise optimization method comprises the steps: obtaining an initial interference image containing multiple types of focusing noise, inputting the initial interference image into a preset noise error correlation model, and obtaining the noise influence coefficient of each type of focusing noise, the noise error correlation model is obtained by training the to-be-trained model based on an interference image sample, the interference image sample comprises multiple types of focusing noise and an actual focusing error, and the focusing noise of the corresponding type is removed through a corresponding denoising algorithm based on the noise influence coefficient. According to the method and the device, the to-be-trained model learns the relationship between various types of noise and the focusing error, so that the influence coefficient of various types of focusing noise on the focusing error can be determined. Based on the noise influence coefficient, the focusing noise of the corresponding type is removed in a targeted manner, the wavefront curvature extraction precision is prevented from being influenced, and the focusing precision of the wavefront curvature interference method is further improved.

The invention relates to a waypoint screening and path planning method for near-field measurement of an unmanned aerial vehicle antenna, and the method comprises the steps: carrying out the waypoint screening of a measurement plane through employing an adaptive sampling strategy based on electromagnetic induction, and carrying out the correction of a phase through combining wavefront curvature correction with data-driven residual error modeling. A more accurate electromagnetic propagation matrix is constructed; the contribution of each to-be-selected measurement point on an antenna pattern is evaluated by constructing an electromagnetic propagation matrix, and a certain number of measurement points are selected as waypoints of the unmanned aerial vehicle by setting a threshold value; local search and global search are balanced by combining an improved tabu search algorithm and a north pole sea parrot optimization algorithm. The method can effectively reduce the number of measurement points and the length of a scanning path, solves the problems that an existing path planning algorithm is liable to fall into local optimum, is long in planning time, and is closer to the reality.

This invention discloses a method and apparatus for adjusting a Heriot-Treut solid-state multipass cell based on beam intrinsic calculation, belonging to the field of laser technology. The method includes the following steps: S1, calculating the transmission matrix at the corresponding position within the multipass cell based on the thickness and refractive index of the solid, the refractive index of the gas, and the radius of curvature and spacing parameters of the concave mirrors; S2, determining the incident beam. q Parameters, calculated based on the transmission matrix at the corresponding positions in the multi-pass pool. q Parameters; S3, according to q The parameters are calculated to determine the beam size and wavefront radius of curvature at any position within the Heriot-Lieutenant solid-state multiple-pass cell. Iterative calculations yield the intrinsic modes of the beam within the cell. Steps S4 and S3 are repeated to calculate the intrinsic modes of different incident beams within the cell. The incident beam parameters are then optimized to obtain the desired incident beam and its corresponding optical field and intensity. This invention can quickly and accurately calculate the eigenmodes of a Heriot-Lieutenant solid-state multiple-pass cell.

The present application relates to the field of active optics, and specifically provides a time series filtering-based wavefront correction method for a survey telescope, which obtains time series wavefront data of the telescope through a wavefront curvature sensor, decomposes the time series wavefront data in a spatial domain through Zernike polynomials, forms a time series coefficient sequence for each term of the Zernike polynomials in a time domain, performs frequency domain analysis on each time series coefficient sequence, calculates a power spectrum, uses a Greenwood frequency as a threshold to identify static aberrations, and performs wavefront correction after filtering out dynamic aberrations. The present application effectively separates and filters out high-frequency disturbances introduced by atmospheric turbulence by combining Zernike polynomial decomposition and frequency domain filtering, and accurately realizes low-frequency aberration wavefront correction through active optics.

The application discloses a kind of based on artificial neural network's casting layer stress prediction method, system and storage medium, comprising: with silicon chip as electroforming base, one side of electroforming base is polished, and the other side is provided with conductive layer;Configuration electrocasting groove, collimating light source and wavefront sensor, adjust the relative position of collimating light source, wavefront sensor and electrocasting groove, make the light beam of collimating light source be reflected into wavefront sensor through the polished surface of silicon chip;With direct current or pulse current, electrocasting is carried out in electrocasting groove;Through data acquisition module, electrocasting process data and laser wavefront curvature radius are collected;According to the stress value calculated according to laser wavefront curvature radius, and stress value data and electrocasting process data are converted into neural network adaptation format;Select network type, activation function and hyperparameter, train artificial neural network model to fit the nonlinear relationship between electrocasting parameter and stress value;Stress prediction: input electrocasting parameter to artificial neural network model, output predicted casting layer stress value.