Adaptive optics(AO)has significantly advanced high-resolution solar observations by mitigating atmospheric turbulence.However,traditional post-focal AO systems suffer from external configurations that introduce excess...Adaptive optics(AO)has significantly advanced high-resolution solar observations by mitigating atmospheric turbulence.However,traditional post-focal AO systems suffer from external configurations that introduce excessive optical surfaces,reduced light throughput,and instrumental polarization.To address these limitations,we propose an embedded solar adaptive optics telescope(ESAOT)that intrinsically incorporates the solar AO(SAO)subsystem within the telescope's optical train,featuring a co-designed correction chain with a single Hartmann-Shack full-wavefront sensor(HS f-WFS)and a deformable secondary mirror(DSM).The HS f-WFS uses temporal-spatial hybrid sampling technique to simultane-ously resolve tip-tilt and high-order aberrations,while the DSM performs real-time compensation through adaptive modal optimization.This unified architecture achieves symmetrical polarization suppression and high system throughput by min-imizing optical surfaces.A 600 mm ESAOT prototype incorporating a 12×12 micro-lens array HS f-WFS and 61-actuator piezoelectric DSM has been developed and successfully conducted on-sky photospheric observations.Validations in-cluding turbulence simulations,optical bench testing,and practical observations at the Lijiang observatory collectively confirm the system's capability to maintain aboutλ/10 wavefront error during active region tracking.This architectural breakthrough of the ESAOT addresses long-standing SAO integration challenges in solar astronomy and provides scala-bility analyses confirming direct applicability to the existing and future large solar observation facilities.展开更多
To address the installation challenges of a 2-m ring Gregorian telescope system,and similar optical systems with a small width-to-radius ratio,we propose a detection method combining local interferometry with a compar...To address the installation challenges of a 2-m ring Gregorian telescope system,and similar optical systems with a small width-to-radius ratio,we propose a detection method combining local interferometry with a comparison model.This method enhances the precision of system calibration by establishing a dataset that delineates the relationship between secondary mirror misalignment and wavefront aberration,subsequently inferring the misalignment from interferometric detection results during the calibration process.For the 2-m ring telescope,we develop a detection model using five local sub-apertures,enabling a root-mean-square detection accuracy of 0:0225λ(λ=632:8 nm)for full-aperture wavefront aberration.The calibration results for the 2-m Ring Solar Telescope system indicate that the root-mean-square value of sub-aperture wavefront aberration reaches 0.104λ,and the root-mean-square value of spliced full-aperture measurement yields reaches 0.112λ.This method offers a novel approach for calibrating small width-toradius ratio telescope systems and can be applied to the calibration of other irregular-aperture optical systems.展开更多
Antarctic telescopes,especially those located at Dome A,face significant reliability challenges owing to the extremely harsh working environment,among which the reliability of the control system is critical in ensurin...Antarctic telescopes,especially those located at Dome A,face significant reliability challenges owing to the extremely harsh working environment,among which the reliability of the control system is critical in ensuring stable operation.This paper describes various factors affecting the reliability of Antarctic telescopes,as well as the challenges of reliability improvement.Combined with the development of Antarctic telescopes and the experience of Antarctic scientific expeditions,we introduce,in detail,the optimization strategy for reliability enhancement,including the hardware layer,software layer,modular design to facilitate maintenance,and reliability management.The current status of the Antarctic Survey Telescope(AST3)is also briefly introduced,along with future development plans.We aim to provide ideas for the reliability design of Antarctic telescopes and provide technical support for the development of future Antarctic telescopes.展开更多
Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulatio...Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulation,low power consumption,and unattended operation,introduce challenges to the design and development of motor drives.We present the design of a permanent magnet synchronous motor suitable for this environment,conducting a quantitative analysis on the impacts of cryogenic conditions on lubricant performance,differential thermal contraction of metallic components,and remanent flux density of neodymium iron boron(N52)permanent magnets.We also implement a labyrinth seal structure,combined with silicone sealing rings,to mitigate ice crystal intrusion risks.Finite element analysis and laboratory tests demonstrate a maximum torque output of 25 Nm.This kind of motor is used in the Antarctic 15 cm Near Infrared Telescope at Dome A,Antarctica.Operation data shows a total encoder feedback error of 0.0678"for the telescope control system with 15"s^(−1)tracking speed at−56.79°C.These results comprehensively validate the high reliability and precision of the motor under the extreme conditions of the polar environment.展开更多
This paper presents a comprehensive analysis of the photometric system of the University of Chinese Academy of Sciences 70 cm Telescope located at the Yan-qi Lake campus of the University of Chinese Academy of Science...This paper presents a comprehensive analysis of the photometric system of the University of Chinese Academy of Sciences 70 cm Telescope located at the Yan-qi Lake campus of the University of Chinese Academy of Sciences.We evaluated the linearity,bias stability,and dark current of the camera.Utilizing the Johnson-Cousins Blue-Visible-Red-Infrared filter system and an Andor DZ936 charge-coupled device camera,we conducted extensive observations of Landolt standard stars to determine the color terms,atmospheric extinction coefficients,photometric zero-points,and the sky background brightness.The results indicate that this telescope demonstrates excellent performance in photometric calibration and good system performance overall,meeting the requirements for limited scientific research and teaching purposes.展开更多
Scientists have been searching for possible new particles beyond the standard model(SM),the theory that has predicted the building bricks that have constituted the known matter world today,including the Higgs-“the l...Scientists have been searching for possible new particles beyond the standard model(SM),the theory that has predicted the building bricks that have constituted the known matter world today,including the Higgs-“the last”SM particle.展开更多
To further improve the pointing accuracy of altazimuth telescopes,this study takes the NAOC 2.5 m telescope as the research object and develops a comprehensive pointing model.The paper rst analyzes the causes of error...To further improve the pointing accuracy of altazimuth telescopes,this study takes the NAOC 2.5 m telescope as the research object and develops a comprehensive pointing model.The paper rst analyzes the causes of errors and accordingly constructs three core models:the basic parametric model,the spherical harmonic model,and the polynomial regression model.Among them,the basic parametric model aims to t error terms with clear physical meanings,but its correction capability is limited and cannot fully cover all in uencing factors.To address this limitation,a spherical harmonic model is introduced.This model demonstrates excellent performance in handling higher-order error terms and can accurately t errors across the celestial sphere.Additionally,a polynomial regression model is designed to improve the tting capability and prediction accuracy for nonlinear errors by exibly adjusting the polynomial order.The resulting comprehensive pointing model combines the advantages of these three models,enabling more precise and complete correction of pointing errors while balancing computational complexity and accuracy by adjusting the tting weight of each model.Experimental veri cation shows that the telescope’s pointing accuracy is improved from 17".805 to 3".1029,meeting the requirements for high-precision astronomical observations.展开更多
The Ground-based Wide-Angle Cameras array necessitates the integration of more than 100 hardware devices,100 servers,and 2500 software modules that must be synchronized within a 3-second imaging cycle.However,the comp...The Ground-based Wide-Angle Cameras array necessitates the integration of more than 100 hardware devices,100 servers,and 2500 software modules that must be synchronized within a 3-second imaging cycle.However,the complexity of real-time,high-concurrency processing of large datasets has historically resulted in substantial failure rates,with an observation efficiency estimated at less than 50%in 2023.To mitigate these challenges,we developed a monitoring system designed to improve fault diagnosis efficiency.It includes two innovative monitoring views for“state evolution”and“transient lifecycle”.Combining these with“instantaneous state”and“key parameter”monitoring views,the system represents a comprehensive monitoring strategy.Here we detail the system architecture,data collection methods,and design philosophy of the monitoring views.During one year of fault diagnosis experimental practice,the proposed system demonstrated its ability to identify and localize faults within minutes,achieving fault localization nearly ten times faster than traditional methods.Additionally,the system design exhibited high generalizability,with possible applicability to other telescope array systems.展开更多
The China Space Station Telescope(CSST)is a 2 m three-mirror anastigmat equipped with a Fast Steering Mirror(FSM),which is part of its precision image stabilization system.The FSM is used to compensate for residuals f...The China Space Station Telescope(CSST)is a 2 m three-mirror anastigmat equipped with a Fast Steering Mirror(FSM),which is part of its precision image stabilization system.The FSM is used to compensate for residuals from the previous stage of the image stabilization system.However,a new type of image stabilization residual caused by image rotation and projection distortion is introduced when the FSM performs tip-tilt adjustments,reducing both the image stabilization accuracy and the absolute pointing accuracy of the CSST.In this paper,we propose a scheme to compute the image stabilization residuals across the full field of view(FOV)by using a reference star as the target for stabilization control,which can be utilized for subsequent image position correction.To achieve this,we developed a linear optical model for image point displacement by simplifying an existing image point displacement model and incorporating more readily available parameters.The computational accuracy of the new model is equivalent to that of the original,with computational differences of less than 0.03μm.Based on this linear model,we established a calculation model for image stabilization residuals,including those due to image rotation and projection distortion caused by FSM tip-tilt adjustments.This model provides a theoretical foundation for quantifying such residuals during the image stabilization process.Finally,the results of testing using this scheme are provided.Experimental results demonstrate that within the observation FOV of the CSST,when the FSM tilts by(1″,1″),the maximum absolute value of the image stabilization residuals accounts for 20%of the total image stabilization accuracy requirement.This finding underscores the necessity of computing and correcting these residuals to meet performance requirements.展开更多
As a facility used for astronomical research, the Lijiang 2.4-m telescope of Yunnan Astronomical Observatories, requires the ability to change one auxiliary instrument with another in as short a time as possible. This...As a facility used for astronomical research, the Lijiang 2.4-m telescope of Yunnan Astronomical Observatories, requires the ability to change one auxiliary instrument with another in as short a time as possible. This arises from the need to quickly respond to scientific programs （e.g. transient observation, time domain studies） and changes in observation conditions （e.g. seeing and weather conditions）. In this paper, we describe the design, construction and test of hardware and software in the rapid instrument exchange system （RIES） for the Cassegrain focal station of this telescope, which enables instruments to be quickly changed at night without much loss of observing time. Tests in the laboratory and at the telescope show that the image quality and pointing accuracy of RIES are satisfactory. With RIES, we observed the same Landolt standard stars almost at the same time with the Princeton Instruments VersArray 1300B Camera （PICCD） and the Yunnan Faint Object Spectrograph and Camera （YFOSC）, while both were mounted at the Cassegrain focus. A quasi-simultaneous comparison shows that the image quality of the optical system inside the YFOSC is comparable with that provided by the PICCD.展开更多
With the growing significance of space weather forecasting,multi-layer magnetic and helioseismic telescopes are emerging as a key area of research.However,owing to the diverse operational processes and sophisticated h...With the growing significance of space weather forecasting,multi-layer magnetic and helioseismic telescopes are emerging as a key area of research.However,owing to the diverse operational processes and sophisticated hardware configurations of these devices,there is an urgent need for efficient autonomous observation capabilities.An autonomous Master Control System(MCS)can ensure efficient performance,data consistency,and stability,and the prototype presented here adopts a microservices architecture,breaking down the hardware into multiple subsystems and converting their functions into individual services.A central decision-making system leads the operations,supported by three auxiliary systems and three device control systems.Through inter-subsystem service calls,it achieves rapid imaging and spectroscopic monitoring.To verify system stability and observation efficiency,the system was tested on the Solar Full-disk Multi-layer Magnetograph.Experimental results verify this system can operate automatically for 4 consecutive months,acquire photospheric vector magnetic and Doppler velocity fields within a 15-minute interval,and measure chromospheric longitudinal magnetic and Doppler velocity fields in under 180 s.This ensures consistent and stable solar monitoring and serves as a practical methodological benchmark for the development of similar devices.展开更多
Significant optical engineering advances at the University of Arizona are being made for design, fabrication, and construction of next generation astronomical telescopes. This summary review paper focuses on the techn...Significant optical engineering advances at the University of Arizona are being made for design, fabrication, and construction of next generation astronomical telescopes. This summary review paper focuses on the technological advances in three key areas. First is the optical fabrication technique used for constructing next-generation telescope mirrors. Advances in ground-based telescope control and instrumentation comprise the second area of development. This includes active alignment of the laser truss-based Large Binocular Telescope(LBT) prime focus camera, the new MOBIUS modular cross-dispersion spectroscopy unit used at the prime focal plane of the LBT, and topological pupil segment optimization. Lastly, future space telescope concepts and enabling technologies are discussed. Among these, the Nautilus space observatory requires challenging alignment of segmented multi-order diffractive elements. The OASIS terahertz space telescope presents unique challenges for characterizing the inflatable primary mirror, and the Hyperion space telescope pushes the limits of high spectral resolution, far-UV spectroscopy. The Coronagraphic Debris and Exoplanet Exploring Pioneer(CDEEP) is a Small Satellite(Small Sat) mission concept for high-contrast imaging of circumstellar disks and exoplanets using vector vortex coronagraph. These advances in optical engineering technologies will help mankind to probe, explore, and understand the scientific beauty of our universe.展开更多
The Lijiang 2.4-meter Telescope(LJT), the largest common-purpose optical telescope in China,has been available to the worldwide astronomical community since 2008. It is located at the Gaomeigu site,Lijiang Observatory...The Lijiang 2.4-meter Telescope(LJT), the largest common-purpose optical telescope in China,has been available to the worldwide astronomical community since 2008. It is located at the Gaomeigu site,Lijiang Observatory(LJO), in the southwest of China. The site has very good observational conditions.During its 10-year operation, several instruments have been equipped on the LJT. Astronomers can perform both photometric and spectral observations. The main scientific goals of LJT include recording photometric and spectral evolution of supernovae, reverberation mapping of active galactic nuclei, investigating the physical properties of binary stars and near-earth objects(comets and asteroids), and identification of exoplanets and all kinds of transients. Until now, the masses of 41 high accretion rate black holes have been measured, and more than 168 supernovae have been identified by the LJT. More than 190 papers related to the LJT have been published. In this paper, the general observation conditions of the Gaomeigu site is introduced at first. Then, the structure of the LJT is described in detail, including the optical, mechanical, motion and control system. The specification of all the instruments and some detailed parameters of the YFOSC is also presented. Finally, some important scientific results and future expectations are summarized.展开更多
The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progres...The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3 nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process.展开更多
In this article, we report the principle and conceptual design of a fundamentally different technology in fabricating high precision aberration free optical devices. The tip-tilt of facet in a mirror array is produced...In this article, we report the principle and conceptual design of a fundamentally different technology in fabricating high precision aberration free optical devices. The tip-tilt of facet in a mirror array is produced by digitally controlled line-tilts of rows and columns. It has not only provided a cost-effective designing methodology in optical physics but also led to a much finer precision of 1 mili arc sec or less. As examples of the application of the proposed digitalised optics, two case studies have been given： a 10 m Schmidt telescope （off-axis） and an 8 m Cassegrain telescope （on-axis）.展开更多
This paper reports on the installation and observations of a new solar telescope installed on 2014 October 7 at the Kodaikanal Observatory. The telescope is a refractive type equipped with a tunable Lyot Hα filter. A...This paper reports on the installation and observations of a new solar telescope installed on 2014 October 7 at the Kodaikanal Observatory. The telescope is a refractive type equipped with a tunable Lyot Hα filter. A CCD camera with size 2k ×2k acquires images of the Sun and has a pixel size of 1.21″ pixel^-1 and a full field-of-view of 41＇. The telescope is equipped with a guiding system which keeps the image of the Sun within a few pixels throughout the observations. The FWHM of the Lyot filter is 0.4A and the filter is motorized, capable of scanning the Hα line profile at a smaller step size of 0.01 A. Partial-disk imaging covering about 10＇ is also possible with the help of a relay lens kept in front of the CCD camera. In this paper, we report the detailed specifications of the telescope, filter unit, the installation, observations and the procedures we have followed to calibrate and align the data. We also present preliminary results with this new full-disk telescope.展开更多
The Solar Guide Telescope (SGT), an important solar attitude sensor of theSST (Space Solar Telescope, a space solar observing instrument being developed in China), canaccurately produce pointing error signals of the S...The Solar Guide Telescope (SGT), an important solar attitude sensor of theSST (Space Solar Telescope, a space solar observing instrument being developed in China), canaccurately produce pointing error signals of the SST for attitude control at high speed. We analyzein detail the error algorithm of the heliocentric coordinates and the edge judging of solar images.The measuring accuracy of +- 0.5 arcsec of the SGT is verified by experiments on the tracking of theSun and by testing a sun simulator. Some factors causing the pointing errors are examined.展开更多
In order to achieve the optimized design of a cased telescoped ammunition(CTA) interior ballistic design,a genetic algorithm was introduced into the optimal design of CTA interior ballistics with coupling the CTA inte...In order to achieve the optimized design of a cased telescoped ammunition(CTA) interior ballistic design,a genetic algorithm was introduced into the optimal design of CTA interior ballistics with coupling the CTA interior ballistic model. Aiming at the interior ballistic characteristics of a CTA gun, the goal of CTA interior ballistic design is to obtain a projectile velocity as large as possible. The optimal design of CTA interior ballistic is carried out using a genetic algorithm by setting peak pressure, changing the chamber volume and gun powder charge density. A numerical simulation of interior ballistics based on a 35 mm CTA firing experimental scheme was conducted and then the genetic algorithm was used for numerical optimization. The projectile muzzle velocity of the optimized scheme is increased from 1168 m/s for the initial experimental scheme to 1182 m/s. Then four optimization schemes were obtained with several independent optimization processes. The schemes were compared with each other and the difference between these schemes is small. The peak pressure and muzzle velocity of these schemes are almost the same. The result shows that the genetic algorithm is effective in the optimal design of the CTA interior ballistics. This work will be lay the foundation for further CTA interior ballistic design.展开更多
A nonlinear dynamic modeling method for primary mirror of Flower-like Deployable Space Telescope(F-DST)undergoing large deployment motion is proposed in this paper.To ensure pointing accuracy and attitude stability of...A nonlinear dynamic modeling method for primary mirror of Flower-like Deployable Space Telescope(F-DST)undergoing large deployment motion is proposed in this paper.To ensure pointing accuracy and attitude stability of the paraboloidal primary mirror,the mirror is discretized into equal thickness shell elements by considering shell curvature.And the material nonlinear constitutive relation of flexible mirror is acquired using Absolute Nodal Coordinate Formulation(ANCF).Furthermore,the primary mirror of F-DST can be regarded as a clustered multi-body system,and its dynamic equations of elastic deformation and deployment motion are established by virtual work principle.Finally,the deployment motion of primary mirror by different driving conditions are simulated,the results show that the vibrations of mirrors that driven by elastic hinge device are more than that driven by servo motor.In addition,single sub-mirror deployment process will perturb the pointing accuracy of primary mirror,and the multiple sub-mirrors simultaneously deploying will seriously affect all the sub-mirrors surface accuracy because of the coupling effect.Thus,there are theoretical value and practical significance for the controlling surface accuracy and attitude accuracy of space telescope.展开更多
基金support from the National Science Foundation of China(NSFC)(Grants No.12293031 and No.61905252)the National Science Foundation for Distinguished Young Scholars(Grant No.12022308)the National Key R&D Program of China(Grants No.2021YFC2202200 and No.2021YFC2202204).
文摘Adaptive optics(AO)has significantly advanced high-resolution solar observations by mitigating atmospheric turbulence.However,traditional post-focal AO systems suffer from external configurations that introduce excessive optical surfaces,reduced light throughput,and instrumental polarization.To address these limitations,we propose an embedded solar adaptive optics telescope(ESAOT)that intrinsically incorporates the solar AO(SAO)subsystem within the telescope's optical train,featuring a co-designed correction chain with a single Hartmann-Shack full-wavefront sensor(HS f-WFS)and a deformable secondary mirror(DSM).The HS f-WFS uses temporal-spatial hybrid sampling technique to simultane-ously resolve tip-tilt and high-order aberrations,while the DSM performs real-time compensation through adaptive modal optimization.This unified architecture achieves symmetrical polarization suppression and high system throughput by min-imizing optical surfaces.A 600 mm ESAOT prototype incorporating a 12×12 micro-lens array HS f-WFS and 61-actuator piezoelectric DSM has been developed and successfully conducted on-sky photospheric observations.Validations in-cluding turbulence simulations,optical bench testing,and practical observations at the Lijiang observatory collectively confirm the system's capability to maintain aboutλ/10 wavefront error during active region tracking.This architectural breakthrough of the ESAOT addresses long-standing SAO integration challenges in solar astronomy and provides scala-bility analyses confirming direct applicability to the existing and future large solar observation facilities.
基金supported by the Jiangsu Provincial Key Research and Development Program(BE2022072)the National Natural Science Foundation of China(12141304)the Natural Science Foundation of Jiangsu Province(BK20231134).
文摘To address the installation challenges of a 2-m ring Gregorian telescope system,and similar optical systems with a small width-to-radius ratio,we propose a detection method combining local interferometry with a comparison model.This method enhances the precision of system calibration by establishing a dataset that delineates the relationship between secondary mirror misalignment and wavefront aberration,subsequently inferring the misalignment from interferometric detection results during the calibration process.For the 2-m ring telescope,we develop a detection model using five local sub-apertures,enabling a root-mean-square detection accuracy of 0:0225λ(λ=632:8 nm)for full-aperture wavefront aberration.The calibration results for the 2-m Ring Solar Telescope system indicate that the root-mean-square value of sub-aperture wavefront aberration reaches 0.104λ,and the root-mean-square value of spliced full-aperture measurement yields reaches 0.112λ.This method offers a novel approach for calibrating small width-toradius ratio telescope systems and can be applied to the calibration of other irregular-aperture optical systems.
基金supported by the National Natural Science Foundation of China (12303089, 11973065)the Jiangsu Funding Program for Excellent Postdoctoral Talent (2022ZB449)the Polar Research Institute of China (PRIC) for their support and help with the Antarctic telescope project
文摘Antarctic telescopes,especially those located at Dome A,face significant reliability challenges owing to the extremely harsh working environment,among which the reliability of the control system is critical in ensuring stable operation.This paper describes various factors affecting the reliability of Antarctic telescopes,as well as the challenges of reliability improvement.Combined with the development of Antarctic telescopes and the experience of Antarctic scientific expeditions,we introduce,in detail,the optimization strategy for reliability enhancement,including the hardware layer,software layer,modular design to facilitate maintenance,and reliability management.The current status of the Antarctic Survey Telescope(AST3)is also briefly introduced,along with future development plans.We aim to provide ideas for the reliability design of Antarctic telescopes and provide technical support for the development of future Antarctic telescopes.
基金supported by the Space Debris Resear-ch Project,China(KJSP2020010102)the NationalKey R&D Program of China(2022YFC2807300).
文摘Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulation,low power consumption,and unattended operation,introduce challenges to the design and development of motor drives.We present the design of a permanent magnet synchronous motor suitable for this environment,conducting a quantitative analysis on the impacts of cryogenic conditions on lubricant performance,differential thermal contraction of metallic components,and remanent flux density of neodymium iron boron(N52)permanent magnets.We also implement a labyrinth seal structure,combined with silicone sealing rings,to mitigate ice crystal intrusion risks.Finite element analysis and laboratory tests demonstrate a maximum torque output of 25 Nm.This kind of motor is used in the Antarctic 15 cm Near Infrared Telescope at Dome A,Antarctica.Operation data shows a total encoder feedback error of 0.0678"for the telescope control system with 15"s^(−1)tracking speed at−56.79°C.These results comprehensively validate the high reliability and precision of the motor under the extreme conditions of the polar environment.
基金supported by National Key R&D Program of China(2023YFA1609700)Research and Education Integration Funding。
文摘This paper presents a comprehensive analysis of the photometric system of the University of Chinese Academy of Sciences 70 cm Telescope located at the Yan-qi Lake campus of the University of Chinese Academy of Sciences.We evaluated the linearity,bias stability,and dark current of the camera.Utilizing the Johnson-Cousins Blue-Visible-Red-Infrared filter system and an Andor DZ936 charge-coupled device camera,we conducted extensive observations of Landolt standard stars to determine the color terms,atmospheric extinction coefficients,photometric zero-points,and the sky background brightness.The results indicate that this telescope demonstrates excellent performance in photometric calibration and good system performance overall,meeting the requirements for limited scientific research and teaching purposes.
文摘Scientists have been searching for possible new particles beyond the standard model(SM),the theory that has predicted the building bricks that have constituted the known matter world today,including the Higgs-“the last”SM particle.
文摘To further improve the pointing accuracy of altazimuth telescopes,this study takes the NAOC 2.5 m telescope as the research object and develops a comprehensive pointing model.The paper rst analyzes the causes of errors and accordingly constructs three core models:the basic parametric model,the spherical harmonic model,and the polynomial regression model.Among them,the basic parametric model aims to t error terms with clear physical meanings,but its correction capability is limited and cannot fully cover all in uencing factors.To address this limitation,a spherical harmonic model is introduced.This model demonstrates excellent performance in handling higher-order error terms and can accurately t errors across the celestial sphere.Additionally,a polynomial regression model is designed to improve the tting capability and prediction accuracy for nonlinear errors by exibly adjusting the polynomial order.The resulting comprehensive pointing model combines the advantages of these three models,enabling more precise and complete correction of pointing errors while balancing computational complexity and accuracy by adjusting the tting weight of each model.Experimental veri cation shows that the telescope’s pointing accuracy is improved from 17".805 to 3".1029,meeting the requirements for high-precision astronomical observations.
基金supported by the Young Data Scientist Program of the China National Astronomical Data Center,the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0550401)the National Natural Science Foundation of China(12494573).
文摘The Ground-based Wide-Angle Cameras array necessitates the integration of more than 100 hardware devices,100 servers,and 2500 software modules that must be synchronized within a 3-second imaging cycle.However,the complexity of real-time,high-concurrency processing of large datasets has historically resulted in substantial failure rates,with an observation efficiency estimated at less than 50%in 2023.To mitigate these challenges,we developed a monitoring system designed to improve fault diagnosis efficiency.It includes two innovative monitoring views for“state evolution”and“transient lifecycle”.Combining these with“instantaneous state”and“key parameter”monitoring views,the system represents a comprehensive monitoring strategy.Here we detail the system architecture,data collection methods,and design philosophy of the monitoring views.During one year of fault diagnosis experimental practice,the proposed system demonstrated its ability to identify and localize faults within minutes,achieving fault localization nearly ten times faster than traditional methods.Additionally,the system design exhibited high generalizability,with possible applicability to other telescope array systems.
基金financially supported by the National Key R&D Program of China(2022YFB3806300)。
文摘The China Space Station Telescope(CSST)is a 2 m three-mirror anastigmat equipped with a Fast Steering Mirror(FSM),which is part of its precision image stabilization system.The FSM is used to compensate for residuals from the previous stage of the image stabilization system.However,a new type of image stabilization residual caused by image rotation and projection distortion is introduced when the FSM performs tip-tilt adjustments,reducing both the image stabilization accuracy and the absolute pointing accuracy of the CSST.In this paper,we propose a scheme to compute the image stabilization residuals across the full field of view(FOV)by using a reference star as the target for stabilization control,which can be utilized for subsequent image position correction.To achieve this,we developed a linear optical model for image point displacement by simplifying an existing image point displacement model and incorporating more readily available parameters.The computational accuracy of the new model is equivalent to that of the original,with computational differences of less than 0.03μm.Based on this linear model,we established a calculation model for image stabilization residuals,including those due to image rotation and projection distortion caused by FSM tip-tilt adjustments.This model provides a theoretical foundation for quantifying such residuals during the image stabilization process.Finally,the results of testing using this scheme are provided.Experimental results demonstrate that within the observation FOV of the CSST,when the FSM tilts by(1″,1″),the maximum absolute value of the image stabilization residuals accounts for 20%of the total image stabilization accuracy requirement.This finding underscores the necessity of computing and correcting these residuals to meet performance requirements.
基金Supported by the National Natural Science Foundation of China
文摘As a facility used for astronomical research, the Lijiang 2.4-m telescope of Yunnan Astronomical Observatories, requires the ability to change one auxiliary instrument with another in as short a time as possible. This arises from the need to quickly respond to scientific programs （e.g. transient observation, time domain studies） and changes in observation conditions （e.g. seeing and weather conditions）. In this paper, we describe the design, construction and test of hardware and software in the rapid instrument exchange system （RIES） for the Cassegrain focal station of this telescope, which enables instruments to be quickly changed at night without much loss of observing time. Tests in the laboratory and at the telescope show that the image quality and pointing accuracy of RIES are satisfactory. With RIES, we observed the same Landolt standard stars almost at the same time with the Princeton Instruments VersArray 1300B Camera （PICCD） and the Yunnan Faint Object Spectrograph and Camera （YFOSC）, while both were mounted at the Cassegrain focus. A quasi-simultaneous comparison shows that the image quality of the optical system inside the YFOSC is comparable with that provided by the PICCD.
基金supported by the National Key R&D Program of China (2022YFF0503800)the Chinese Meridian Project,the National Natural Science Foundation of China (11427901)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA15320102)the Youth Innovation Promotion Association (2022057).
文摘With the growing significance of space weather forecasting,multi-layer magnetic and helioseismic telescopes are emerging as a key area of research.However,owing to the diverse operational processes and sophisticated hardware configurations of these devices,there is an urgent need for efficient autonomous observation capabilities.An autonomous Master Control System(MCS)can ensure efficient performance,data consistency,and stability,and the prototype presented here adopts a microservices architecture,breaking down the hardware into multiple subsystems and converting their functions into individual services.A central decision-making system leads the operations,supported by three auxiliary systems and three device control systems.Through inter-subsystem service calls,it achieves rapid imaging and spectroscopic monitoring.To verify system stability and observation efficiency,the system was tested on the Solar Full-disk Multi-layer Magnetograph.Experimental results verify this system can operate automatically for 4 consecutive months,acquire photospheric vector magnetic and Doppler velocity fields within a 15-minute interval,and measure chromospheric longitudinal magnetic and Doppler velocity fields in under 180 s.This ensures consistent and stable solar monitoring and serves as a practical methodological benchmark for the development of similar devices.
基金the Gordon and Betty Moore Foundation for their financial support of the development of the MODElens and its enabling alignment technologiesthe II-VI Foundation Block-Gift,Technology Research Initiative Fund Optics/Imaging Program。
文摘Significant optical engineering advances at the University of Arizona are being made for design, fabrication, and construction of next generation astronomical telescopes. This summary review paper focuses on the technological advances in three key areas. First is the optical fabrication technique used for constructing next-generation telescope mirrors. Advances in ground-based telescope control and instrumentation comprise the second area of development. This includes active alignment of the laser truss-based Large Binocular Telescope(LBT) prime focus camera, the new MOBIUS modular cross-dispersion spectroscopy unit used at the prime focal plane of the LBT, and topological pupil segment optimization. Lastly, future space telescope concepts and enabling technologies are discussed. Among these, the Nautilus space observatory requires challenging alignment of segmented multi-order diffractive elements. The OASIS terahertz space telescope presents unique challenges for characterizing the inflatable primary mirror, and the Hyperion space telescope pushes the limits of high spectral resolution, far-UV spectroscopy. The Coronagraphic Debris and Exoplanet Exploring Pioneer(CDEEP) is a Small Satellite(Small Sat) mission concept for high-contrast imaging of circumstellar disks and exoplanets using vector vortex coronagraph. These advances in optical engineering technologies will help mankind to probe, explore, and understand the scientific beauty of our universe.
基金supported by the Joint Research Fund in Astronomy (U1631127, U1631129 and U1831204) under cooperative agreement between the National Natural Science Foundation of China (NSFC) and Chinese Academy of Sciences (CAS)the National Natural Science Foundation of China (NSFC) (11473068, 11603072 and 11573067)+1 种基金the National Key R&D Program of China (2018YFA0404603)supported by the Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences (CAS)
文摘The Lijiang 2.4-meter Telescope(LJT), the largest common-purpose optical telescope in China,has been available to the worldwide astronomical community since 2008. It is located at the Gaomeigu site,Lijiang Observatory(LJO), in the southwest of China. The site has very good observational conditions.During its 10-year operation, several instruments have been equipped on the LJT. Astronomers can perform both photometric and spectral observations. The main scientific goals of LJT include recording photometric and spectral evolution of supernovae, reverberation mapping of active galactic nuclei, investigating the physical properties of binary stars and near-earth objects(comets and asteroids), and identification of exoplanets and all kinds of transients. Until now, the masses of 41 high accretion rate black holes have been measured, and more than 168 supernovae have been identified by the LJT. More than 190 papers related to the LJT have been published. In this paper, the general observation conditions of the Gaomeigu site is introduced at first. Then, the structure of the LJT is described in detail, including the optical, mechanical, motion and control system. The specification of all the instruments and some detailed parameters of the YFOSC is also presented. Finally, some important scientific results and future expectations are summarized.
基金supported by National Key R&D Program of China (2022YFF0709101)China National Space Administration (D050104)National Natural Science Foundation of China (62105244 and U2030111)。
文摘The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3 nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process.
文摘In this article, we report the principle and conceptual design of a fundamentally different technology in fabricating high precision aberration free optical devices. The tip-tilt of facet in a mirror array is produced by digitally controlled line-tilts of rows and columns. It has not only provided a cost-effective designing methodology in optical physics but also led to a much finer precision of 1 mili arc sec or less. As examples of the application of the proposed digitalised optics, two case studies have been given： a 10 m Schmidt telescope （off-axis） and an 8 m Cassegrain telescope （on-axis）.
文摘This paper reports on the installation and observations of a new solar telescope installed on 2014 October 7 at the Kodaikanal Observatory. The telescope is a refractive type equipped with a tunable Lyot Hα filter. A CCD camera with size 2k ×2k acquires images of the Sun and has a pixel size of 1.21″ pixel^-1 and a full field-of-view of 41＇. The telescope is equipped with a guiding system which keeps the image of the Sun within a few pixels throughout the observations. The FWHM of the Lyot filter is 0.4A and the filter is motorized, capable of scanning the Hα line profile at a smaller step size of 0.01 A. Partial-disk imaging covering about 10＇ is also possible with the help of a relay lens kept in front of the CCD camera. In this paper, we report the detailed specifications of the telescope, filter unit, the installation, observations and the procedures we have followed to calibrate and align the data. We also present preliminary results with this new full-disk telescope.
基金funded by National 863 Hi-tech Project of China.
文摘The Solar Guide Telescope (SGT), an important solar attitude sensor of theSST (Space Solar Telescope, a space solar observing instrument being developed in China), canaccurately produce pointing error signals of the SST for attitude control at high speed. We analyzein detail the error algorithm of the heliocentric coordinates and the edge judging of solar images.The measuring accuracy of +- 0.5 arcsec of the SGT is verified by experiments on the tracking of theSun and by testing a sun simulator. Some factors causing the pointing errors are examined.
文摘In order to achieve the optimized design of a cased telescoped ammunition(CTA) interior ballistic design,a genetic algorithm was introduced into the optimal design of CTA interior ballistics with coupling the CTA interior ballistic model. Aiming at the interior ballistic characteristics of a CTA gun, the goal of CTA interior ballistic design is to obtain a projectile velocity as large as possible. The optimal design of CTA interior ballistic is carried out using a genetic algorithm by setting peak pressure, changing the chamber volume and gun powder charge density. A numerical simulation of interior ballistics based on a 35 mm CTA firing experimental scheme was conducted and then the genetic algorithm was used for numerical optimization. The projectile muzzle velocity of the optimized scheme is increased from 1168 m/s for the initial experimental scheme to 1182 m/s. Then four optimization schemes were obtained with several independent optimization processes. The schemes were compared with each other and the difference between these schemes is small. The peak pressure and muzzle velocity of these schemes are almost the same. The result shows that the genetic algorithm is effective in the optimal design of the CTA interior ballistics. This work will be lay the foundation for further CTA interior ballistic design.
基金based on Project 51575126 the National Natural Science Foundation of ChinaProjects 2013M541358 and 2015T80358 the China Postdoctoral Science Foundation。
文摘A nonlinear dynamic modeling method for primary mirror of Flower-like Deployable Space Telescope(F-DST)undergoing large deployment motion is proposed in this paper.To ensure pointing accuracy and attitude stability of the paraboloidal primary mirror,the mirror is discretized into equal thickness shell elements by considering shell curvature.And the material nonlinear constitutive relation of flexible mirror is acquired using Absolute Nodal Coordinate Formulation(ANCF).Furthermore,the primary mirror of F-DST can be regarded as a clustered multi-body system,and its dynamic equations of elastic deformation and deployment motion are established by virtual work principle.Finally,the deployment motion of primary mirror by different driving conditions are simulated,the results show that the vibrations of mirrors that driven by elastic hinge device are more than that driven by servo motor.In addition,single sub-mirror deployment process will perturb the pointing accuracy of primary mirror,and the multiple sub-mirrors simultaneously deploying will seriously affect all the sub-mirrors surface accuracy because of the coupling effect.Thus,there are theoretical value and practical significance for the controlling surface accuracy and attitude accuracy of space telescope.
