最新刊期
卷 34 ， 期 17 ， 2026
- 摘要：To overcome the limitations of independently calculated thermal and gravitational deformations， as well as single-attitude analyses， in accurately representing the operational state of the main focal plane of a cryogenic （4×4） mosaic detector， a cryogenic multi-attitude flatness-error allocation method based on coupled thermal-structural analysis is proposed. A finite-element model incorporating the detector， mosaic substrate， shims， and support structure was established. Steady-state thermal analysis was first conducted， after which the resulting temperature field was mapped onto the structural model. Gravitational loads corresponding to attitudes of 0°， 30°， 45°， 60°， and 90° were subsequently applied under cryogenic thermal–structural coupled conditions. Normal displacements at the main focal-plane nodes were extracted， and peak-to-valley （PV） values were calculated after removal of the best-fit plane. The PV values of the main focal plane at the five attitudes were determined to be 4.771， 5.182， 7.962， 6.100， and 8.099 μm， respectively. The maximum PV value occurred at the 90° attitude， representing a 69.7% increase relative to that at 0°. The 45° and 90° attitudes were identified as the governing conditions. Based on the cryogenic multi-attitude coupled analysis， the total flatness-error allocation for the main focal plane was determined to be 38.7 μm. The proposed method enables a more realistic characterization of focal-plane flatness variations under cryogenic operating conditions， avoids error distortion arising from the independent superposition of thermal and gravitational effects， and provides a basis for structural design， assembly adjustment， and engineering-margin determination of cryogenic mosaic focal planes.关键词：mosaic detector;focal plane flatness;low-temperature thermal coupling;error allocation;finite element analysis1|0|0更新时间：2026-09-18
- 摘要：To address inherent geometric errors caused by misalignment between the upper and lower racks of a single door leaf in dual-motor-driven large-dome doors， an error-compensated synchronous control method is proposed. The method reduces unbalanced loads in the dual-motor drive system without requiring additional stress sensors. The structure of the large-dome door and the transmission mechanism of the dual-motor gear-rack system are first described. The rigidly coupled configuration used to drive a single door leaf is clarified， and a mathematical model of the dual-motor gear-rack system is established. The inherent geometric error is subsequently measured using a master–slave scheme， and its relationship with door travel is analyzed and incorporated into the synchronous control algorithm. The robustness of the algorithm under constant-load conditions， over the specified operating-speed range， and under wind resistance is evaluated. Feedback currents of the two motors are compared to assess structural stress variations during operation. Simulation results indicate that the synchronization error varies only slightly within the specified speed range. As wind speed increases from 4 to 7 m/s， the required driving force increases accordingly but remains within the rated torque range of the motors. Experimental results demonstrate that the proposed synchronous control method substantially reduces the difference between the feedback currents of the two motors. The absolute peak current difference is reduced from 1.7 A to 0.7 A， indicating a significant reduction in unbalanced dual-motor drive loads on the single door leaf. The proposed measurement method enables effective identification of inherent geometric errors under physically constrained conditions. The error-compensated synchronous control method effectively reduces internal door stresses induced by unbalanced loads in the dual-motor drive system. The proposed approach is applicable to rigidly coupled dual- or multi-motor drive systems in which geometric errors are difficult to measure directly but are repeatable.关键词：double doors of large dome;dual-motor drive;inherent error compensation;synchronous control1|0|0更新时间：2026-09-18
- 摘要：To improve the orbit-determination accuracy of space targets and enhance spacecraft maneuver-avoidance capability， a design method for a laser-ranging optical system for space targets is investigated. A non-coaxial transceiver laser-ranging optical system comprising a primary optical system and a laser-transmitting system is proposed. The primary optical system employs a 700 mm-aperture Cassegrain configuration. Following initial image formation， collimation and beam splitting are performed to enable both target-monitoring imaging and echo-signal reception. The target-monitoring imaging subsystem operates over a wavelength range of 1 100-1 700 nm， with a focal length of 4 200 mm and a field of view of 0.18°； its image quality approaches the diffraction limit. In the echo-signal receiving subsystem， incident 1 064 nm radiation collected by the primary aperture is collimated into a 12 mm-diameter parallel beam and subsequently focused onto the 80 μm active area of a single-photon detector through a lens group. This subsystem has a focal length of 500 mm and a field of view of 0.01°. The laser-transmitting subsystem achieves 18× beam expansion and emission of a 1 064 nm laser beam through a two-stage lens group and a Coudé optical path. The overall system has been validated through multiple experiments， demonstrating effective and stable ranging of space targets.关键词：space target;laser ranging;optical system;single-photon detector;field of view;focal length2|0|0更新时间：2026-09-18
- 摘要：To address anomalous disturbances in measured surface point clouds， a collaborative denoising method based on Hermite–Birkhoff radial basis function （HRBF） implicit-surface modeling is proposed to improve structural recovery accuracy and noise-suppression performance for complex surfaces. First， the global trend of the point cloud is modeled using an HRBF implicit surface， and residual analysis is employed to preliminarily identify and remove anomalous points. Subsequently， a unified variational model incorporating diffusion regularization is introduced to further refine the surface structure， enabling the effective separation of structural information from noise disturbances. Experimental results demonstrate that， compared with the conventional HRBF method， the proposed approach reduces the root mean square error （RMSE）， peak-to-valley value （PV）， and mean normal error （MNE） by approximately 7.8%， 49.0%， and 34.5%， respectively. Local anomalous disturbances are effectively suppressed while the global surface trend and local geometric continuity are preserved. The proposed method exhibits favorable stability and robustness under complex noise conditions， providing an effective approach for high-precision structural recovery and denoising of complex surface point clouds.关键词：mosaic detector;Point cloud denoising;implicit surface;Hermite-Birkhoff radial basis function;diffusion regularization1|0|0更新时间：2026-09-18
- 摘要：Mirror covers are essential protective devices for the primary mirrors of large astronomical telescopes. Their design directly affects the service life of primary-mirror coatings， telescope availability， and maintenance costs. In this study， the principal structural configurations of mirror covers used in large telescopes worldwide are systematically reviewed and classified into four categories： curtain-type， louver-type， panel-type-including swing-open double-door and petal configurations-and special configurations. The structural principles， representative applications， advantages， and limitations of each category are examined. Based on this classification， the key technologies common to mirror-cover design are summarized from four perspectives： structural materials， drive and control systems， wind-load mechanics， and sealing protection. A comparative assessment of the overall performance of different mirror-cover configurations is also presented. Current challenges in mirror-cover design are identified， and future development trends are discussed， with particular emphasis on lightweight composite materials， intelligent control systems， and deployable space mechanisms. This review provides a systematic reference for configuration selection and engineering design of mirror covers for large-aperture telescopes.关键词：telescope mirror cover;primary mirror protection;curtain-type mirror cover;louver-type mirror cover;panel-type mirror cover;space telescope1|0|0更新时间：2026-09-18
- 摘要：To address the challenge of flatness inspection for mosaic detector focal planes， a co-frame parallel dual-probe measurement system is proposed. To mitigate the systematic errors inherent in this system， a multi-attitude robust decomposition-based error compensation model is developed for high-precision flatness measurement. First， the error transfer mechanism of the co-frame parallel dual-probe measurement configuration is analyzed. Subsequently， exploiting the differing spatial invariance of system errors fixed in the instrument coordinate system and the surface profile of the calibration mirror fixed in the mirror coordinate system， a multi-attitude robust decomposition error compensation model is established. Differential measurement results are decomposed into a system error field， calibration-mirror surface profile， and attitude-drift term. System-error calibration and compensation are then achieved through multi-attitude translation and flipping measurements. Physical experiments demonstrate that， with high-precision Luphoscan measurements used as the reference ground truth， the overall slope and periodic stripe errors in the original differential field are substantially suppressed after compensation. Quantitative results show that the proposed method achieves residual PV， RMSE， and MAE values of 4.400 μm， 0.560 μm， and 0.446 μm， respectively， outperforming comparative methods， including LightGBM. Moreover， the X-direction trend error and Y-direction periodic error are reduced by 97.82% and 85.85%， respectively. The proposed model effectively separates and compensates for fixed systematic errors in the co-frame parallel dual-probe measurement system， thereby providing an effective approach for high-precision flatness inspection of mosaic detector focal planes.关键词：optical testing;mosaic detector;differential measurement;flatness inspection;systematic error compensation1|0|0更新时间：2026-09-18
Precision Optics Empowering Modern Astronomy Research\—Frontier Technologies and Methods in Astronomical Optics
- 摘要：In fringe projection profilometry （FPP）， the resolution of fringe and phase data is constrained by imaging hardware， while existing super-resolution methods remain limited in their ability to recover fine details. To improve three-dimensional reconstruction accuracy， a diffusion-based wrapped-phase super-resolution method， termed Phase Diffusion Super-Resolution （PhaseDiffSR）， is proposed. A phase super-resolution framework is constructed on the basis of the residual-shifting diffusion model， ResShift， in which high-resolution phase components are recovered through a low-resolution-condition-guided reverse denoising process. Furthermore， because the modulation map reflects fringe contrast and local phase reliability， the low-resolution modulation map is introduced as an additional condition to jointly guide reverse denoising with the low-resolution phase components. Experimental results demonstrate that PhaseDiffSR achieves superior reconstruction performance across different super-resolution scales. For the ×2 and ×4 tasks， the mean absolute errors of the reconstructed wrapped phase are 0.0309 rad and 0.0429 rad， respectively， while the root-mean-square errors of the three-dimensional Euclidean distances of the point clouds are 0.189 mm and 0.296 mm， respectively. These results outperform those of the compared methods， demonstrating that PhaseDiffSR effectively enhances the accuracy of wrapped-phase super-resolution and transfers phase-level improvements to subsequent three-dimensional point-cloud reconstruction.关键词：fringe projection profilometry;wrapped phase;Super-resolution;diffusion model;3D reconstruction1|0|0更新时间：2026-09-18
- 摘要：Accurate calibration of the transmission profiles of tunable liquid-crystal birefringent filters is essential for precise measurements of solar magnetic and velocity fields by solar telescopes. Conventional calibration methods are often constrained by limited spectral resolution and poor adaptability to system-level calibration or by inadequate stability and high cost. To overcome these limitations， a novel calibration method based on fixed-wavelength ultra-narrow-linewidth continuous-wave lasers is proposed. By exploiting the narrow linewidth， low noise， and high stability of single-frequency continuous-wave lasers， a concise and efficient system-level calibration scheme is established. The operating principle of the laser-based calibration method is systematically analyzed. Theoretical derivations demonstrate that ultra-narrowband lasers can effectively suppress phase crosstalk among multistage optical units， enabling accurate calibration of both the central wavelength and transmission profile. On this basis， a dedicated laser calibration system is developed， and comparative experiments are conducted against a conventional method based on high-resolution spectrometers. The experimentally measured transmission profiles obtained using the proposed method are in excellent agreement with end-to-end numerical simulation results， while the sideband profiles are substantially improved relative to those obtained using conventional approaches. In addition， solar characteristic spectral lines scanned by the filter are successfully acquired through on-sky observations. The proposed method has been applied to the transmission-profile calibration of prototype filters for the Magnetic and Helioseismic Imager （MHI） of the Solar Polar Orbit Observatory （SPO）. It also provides a broadly applicable technical framework and practical reference for the high-precision calibration of various narrowband tunable filters.关键词：ultra-narrowband laser;filter;transmission profile;solar telescope;calibration1|0|0更新时间：2026-09-18
Modern Applied Optics
- 摘要：Cemented carbide is a high-hardness， electrically conductive， and difficult-to-machine material that is widely used in cutting-tool inserts and molds for low-cost， high-volume manufacturing. The fabrication of arrayed functional microstructures on cemented-carbide surfaces is often required. Electrical discharge machining （EDM） is a promising method for producing such microstructures； however， severe tool-electrode wear remains a major challenge. Based on the principle of die-sinking EDM using composite material electrodes （CMEs）， a self-sharpening CME was developed by bonding and clamping two high-wear-rate electrode foils on either side of a low-wear-rate central foil. The proposed electrode was applied to EDM of arrayed deep narrow grooves. During machining， the outer foil sub-electrodes were preferentially worn， such that the groove width and depth were primarily governed by the central low-wear-rate sub-electrode. Meanwhile， adaptive discharge sharpening occurred during the machining process， preventing excessive exposure， deformation， and fracture of the extremely thin central sub-electrode. A CME composed of Cu foil and H62 brass foil was fabricated based on this design. The effects of open-circuit voltage， pulse frequency， and Cu-foil sub-electrode thickness on EDM performance were investigated. Dense arrays of deep narrow grooves with depths exceeding 2.2 mm and an aspect ratio of 12 were successfully machined. The results demonstrate that the proposed self-sharpening CME is particularly suitable for batch EDM fabrication of surface microstructures on difficult-to-machine materials， such as cemented carbide.关键词：electrical discharge machining;composite material electrode;cemented carbide;deep narrow groove1|0|0更新时间：2026-09-18
- 摘要：To improve azimuth estimation accuracy in measurement while drilling （MWD）， an online magnetic-error compensation method based on the Magnetic-Inertial Arctic Puffin Optimization （MIAPO） algorithm is proposed. Downhole magnetometers are susceptible to complex magnetic interference， which can substantially degrade azimuth estimation accuracy. Sources of magnetometer errors under complex drilling conditions are analyzed， and a comprehensive compensation model is established according to their error characteristics. Based on the stable spatial geometric relationship between the gravity and geomagnetic vectors， an objective function is formulated for identifying magnetometer error parameters. To address the slow convergence and susceptibility of the conventional Arctic Puffin Optimization （APO） algorithm to local optima， three targeted enhancements are incorporated. A dynamic centroid opposition-based learning strategy is introduced to strengthen global search capability； a fitness-ranking-based attention mechanism is designed to assign differentiated weights to high-quality candidate solutions， thereby improving local search efficiency and convergence accuracy； and an adaptive threshold mechanism based on fitness dispersion is developed to facilitate escape from local optima. Simulation and field-drilling experiments demonstrate that MIAPO outperforms particle swarm optimization （PSO） and APO in both compensation accuracy and convergence stability. The mean absolute error of the compensated drill-bit azimuth remains within 0.61°. The proposed method effectively enhances the measurement accuracy of microelectromechanical-system （MEMS） magnetometers in MWD applications.关键词：MEMS magnetometer;measurement-while-drilling;arctic puffin optimization algorithm;online error compensation1|0|0更新时间：2026-09-18
- 摘要：To address the limitation of conventional mechanical vibration-isolation indices， which cannot effectively characterize elastic-vibration-induced line-of-sight （LOS） disturbances in large optical vibration-isolation systems， an LOS stability evaluation method for such platforms is proposed. Elastic vibration of the platform is identified as the primary source of LOS disturbance. A virtual LOS model is established to investigate the mechanism by which platform-induced LOS disturbances affect optical testing. The LOS disturbance is decomposed into high-frequency jitter and low-frequency drift， enabling accurate quantification of both components. An engineering analysis model is developed for an optical vibration-isolation platform. The modal characteristics of the platform and the random response characteristics of the virtual LOS disturbance are analyzed in detail， thereby completing the evaluation and quantification of LOS jitter and drift. The results indicate that the seventh-order first vertical bending mode and the eleventh-order first torsional bending mode are the dominant contributors to LOS disturbances in the pitching and yawing directions， respectively. A multi-point synchronous micro-vibration measurement method is subsequently adopted for experimental validation. The measured RMS values of LOS jitter in the pitching and yawing directions are 0.094 6 nrad and 0.160 nrad， respectively， while the corresponding RMS drift values are 0.499 nrad and 0.870 nrad. The maximum relative error between the experimental and simulation results does not exceed 5%， demonstrating the reliability of the proposed analysis method. This approach provides a novel and effective framework for evaluating the stability of large optical vibration-isolation platforms and is of considerable significance for engineering applications.关键词：optical vibration isolation system;optical testing;stability;virtual line-of-sight （LOS）;LOS jitter;LOS drift1|0|0更新时间：2026-09-18
Micro\/Nano Technology and Fine Mechanics
- 摘要：Under low-light conditions， vegetation cover， background clutter， and sensor noise can substantially reduce the contrast between camouflaged targets and their surroundings， thereby limiting the reliability of conventional intensity-based imaging methods. To improve the detection of low-visibility targets in complex vegetated environments， a multimodal imaging detection method integrating low-light intensity， polarization， and spectral information is proposed. First， a Target Separation Index （TSI） is constructed from differences in the spectral responses of targets and vegetation backgrounds in the red and near-infrared bands， thereby enhancing target saliency. Polarization features are subsequently introduced to characterize reflectance differences between camouflaged target surfaces and natural background elements， including soil clumps and dead leaves. TSI， low-light intensity images， and polarization information are then synergistically fused in the HSV color space to generate target-enhanced images. Experimental results demonstrate that， although TSI effectively highlights vegetation-obscured targets， it remains susceptible to interference from environmental clutter. The proposed fusion method further suppresses such false detections and improves target-background discrimination. Validation using a self-built dataset yielded a target contrast of 0.924 and a detection rate of 0.98. In addition， application experiments with the YOLOv10 model showed that the fused images achieved higher target-detection accuracy than single-modality images. By exploiting the complementary characteristics of low-light intensity， spectral response， and polarized reflectance， the proposed method effectively enhances the detection performance of camouflaged targets under dark， vegetation-obscured conditions.关键词：polarization spectral imaging;vegetation;nighttime detection;information fusion1|0|0更新时间：2026-09-18
-
METransUNet segmentation network model for ultra-widefield OCT images of ocular fundus choroid layer AI导读
摘要：Existing fundus choroidal-layer segmentation models are typically trained on conventional optical coherence tomography （OCT） images and are therefore prone to artifacts and boundary oscillations when applied to ultra-widefield OCT images. Inadequate edge-feature extraction and limited global modeling capability further constrain segmentation accuracy in ultra-widefield OCT imaging. To address these limitations， a multi-scale edge-enhanced METransUNet model for choroidal-layer segmentation in ultra-widefield OCT fundus images is developed based on TransUNet. An Edge Enhancement Module （EEM） is incorporated into the skip connections to strengthen edge and texture representations in ultra-widefield OCT feature maps. In addition， an Attention Integration Module （AIM） is embedded in the decoder to facilitate the effective integration of multi-scale features. Experiments conducted on the self-built D-choroid dataset demonstrate that METransUNet achieves an accuracy of 0.993 0， a Dice coefficient of 0.911 4， and an intersection-over-union value of 0.837 2. These results indicate that the proposed model provides effective technical support for intelligent auxiliary diagnosis of choroidal diseases using ultra-widefield OCT. Furthermore， an integrated ultra-widefield OCT image-analysis system encompassing data acquisition， inference， and result output is established， and an engineering architecture is designed to facilitate clinical deployment.关键词：optical coherent tomography;image segmentation;ultra-widefield;choroidal layer segmentation;TransUnet;edge enhancement;multi-scale feature fusion2|0|0更新时间：2026-09-18
Information Sciences
- Address：No.3888 Dong Nanhu Road, Changchun, Jilin, China Postal code：130033
- Tel：0431-86176855 Email：gxjmgc@ciomp.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 吉ICP备11002662号-17
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0