The proposed design of a microwave superconducting kinetic inductance detector(MKID)array readout system characterizes the performance of MKIDs through a digital homodyne frequency mixing architecture.Meanwhile,the re...The proposed design of a microwave superconducting kinetic inductance detector(MKID)array readout system characterizes the performance of MKIDs through a digital homodyne frequency mixing architecture.Meanwhile,the readout system is implemented using a frequency division multiplexing circuit system,coupled with an FFT design to enable the readout of MKID arrays.The system is characterized by its compact size,low cost,portability,and ease of further development.Together,these features have significant implications for the design and readout of terahertz MKID arrays,while simultaneously advancing both the theoretical and practical aspects of MKID technology.展开更多
The infrared Fourier transform spectrometer needs a cold view field diaphragm to reduce stray radiation.For an infrared spectrometer with linear array detectors,the part of the view field diaphragm where the light pas...The infrared Fourier transform spectrometer needs a cold view field diaphragm to reduce stray radiation.For an infrared spectrometer with linear array detectors,the part of the view field diaphragm where the light passes can be regarded as a slit.If the infrared detectors are small in size,the width of the slit is also small,which will cause serious diffraction phenomena.If the widths of the view field diaphragm and the optical system are designed by geometric optics theory,the diffraction light cannot be fully received by the detectors,which will cause energy loss.Expanding the width of the view field diaphragm will introduce stray radiation.Meanwhile,spectrometer follow-up optics should be set in cold environments to reduce the infrared background of the instrument.Optical materials have different thermal characteristics,the optical and mechanical structures will deform at lowtemperature,and the cold view field diaphragm is installed at room temperature,so it is impossible to guarantee that the cold view field diaphragm remains in its design position when working at low-temperature.This paper solves the above problems by designing an adjustable cold view field diaphragm installed in its cryogenic vacuum chamber.The width and position of the view field diaphragm can be adjusted when working in cold temperatures,without opening the cryogenic vacuum chamber.Contrasting the interference signal obtained by the detectors in the adjustment process,the system can get the most suitable width and position of the cold view field diaphragm.The above works are based on the spectrometer used in the study named Accurate Infrared Magnetic Field Measurements of the Sun.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
The Mini-SiTian project,which is a pathfinder for the SiTian project,utilizes three 30 cm telescopes equipped with commercial CMOS cameras(ZWO ASI6200MM Pro)to simulate a large-area time-domain survey.Due to the avoid...The Mini-SiTian project,which is a pathfinder for the SiTian project,utilizes three 30 cm telescopes equipped with commercial CMOS cameras(ZWO ASI6200MM Pro)to simulate a large-area time-domain survey.Due to the avoidance of the traditional mechanical shutter,the CMOS camera is favorable in time-domain survey projects.In the future,the SiTian telescope array will employ a two-by-two scientific-grade mosaic CMOS camera to survey a10,000 degree square area every 30 minutes.Therefore,the performance of CMOS directly determines the detection capability of SiTian telescopes for transient sources,and a comprehensive understanding of the performance of CMOS cameras is crucial.In this research,laboratory testing was conducted to thoroughly evaluate three cameras by assessing several critical parameters,including bias stability,dark current,pixel anomalies,linearity,gain,and read noise.We find exceptional short-term bias stability with standard deviations below 0.02 ADU,negligible dark current of approximately 0.002 e-pixel^(-1)s^(-1)at 0℃,and excellent linearity with nonlinearity consistently below±0.5%,and a small proportion(0.06%-0.08%)of pixels with anomalous responses.Furthermore,our analysis demonstrates uniform gain values across all cameras,ranging from 0.252 to 0.255 e-ADU^(-1),with low readout noise,measured to be below 1.6 e-using conventional methods.We also propose a novel method for pixel-level gain and read noise calculation for CMOS sensors,which revealed a narrow gain distribution and a low median read noise of 1.028 e-for one of the cameras.The laboratory testing of the ZWO ASI6200MM Pro cameras indicates their potential to meet the requirements of time-domain surveys for the Mini-SiTian project.展开更多
The SiTian Project represents a groundbreaking initiative in astronomy,aiming to deploy a global network of telescopes,each with a 1 m aperture,for comprehensive time-domain sky surveys.The network's innovative ar...The SiTian Project represents a groundbreaking initiative in astronomy,aiming to deploy a global network of telescopes,each with a 1 m aperture,for comprehensive time-domain sky surveys.The network's innovative architecture features multiple observational nodes,each comprising three strategically aligned telescopes equipped with filters.This design enables three-color(g,r,i)channel imaging within each node,facilitating precise and coordinated observations.As a pathfinder to the full-scale project,the Mini-SiTian Project serves as the scientific and technological validation platform,utilizing three 30 cm aperture telescopes to validate the methodologies and technologies planned for the broader SiTian network.This paper focuses on the development and implementation of the Master Control System(MCS),and the central command hub for the Mini-SiTian Array.The MCS is designed to facilitate seamless communication with the SiTian Brain,the project's central processing and decisionmaking unit,while ensuring accurate task allocation,real-time status monitoring,and optimized observational workflows.The system adopts a robust architecture that separates front-end and back-end functionalities.A key innovation of the MCS is its ability to dynamically adjust observation plans in response to transient source alerts,enabling rapid and coordinated scans of target sky regions.The paper provides an in-depth analysis of the system's internal components,including the communication system,which is critical for seamless network operation.Extensive testing has validated the functionality,reliability,and compatibility of these components within the overall system architecture.The successful deployment of the MCS in managing the Mini-SiTian Array has demonstrated its practicality and efficacy in collaborative observation and distributed control.By simplifying cluster management and ensuring data integrity,the MCS represents a significant advancement in astronomical observation control systems.Its scalable and adaptable design not only supports the future expansion of the SiTian network but also provides a blueprint for other large-scale telescope arrays,marking a transformative step forward in time-domain astronomy.展开更多
To test the performance of the Chinese whole-surface electromagnetic prospecting （SEP） system, system integrations, instrument performances, and large-scale production viabilities in Liaoning province and Inner Mong...To test the performance of the Chinese whole-surface electromagnetic prospecting （SEP） system, system integrations, instrument performances, and large-scale production viabilities in Liaoning province and Inner Mongolia were measured via extensive field tests. Resultant electric fields, magnetic fields, apparent resistivities, impedance phases, and inversion profiles compared favorably with results of commercial equipment from other countries. The inversion results agreed well with the geologic information from boreholes. Field tests showed that the SEP system is stable, reliable, lightweight, and easy to operate, making it suitable and ready for real-field exploration.展开更多
The state-space representation of linear time-invariant (LTI) fractional order systems is introduced, and a proof of their stability theory is also given. Then an efficient identification algorithm is proposed for tho...The state-space representation of linear time-invariant (LTI) fractional order systems is introduced, and a proof of their stability theory is also given. Then an efficient identification algorithm is proposed for those fractional order systems. The basic idea of the algorithm is to compute fractional derivatives and the filter simultaneously, i.e., the filtered fractional derivatives can be obtained by computing them in one step, and then system identification can be fulfilled by the least square method. The instrumental variable method is also used in the identification of fractional order systems. In this way, even if there is colored noise in the systems, the unbiased estimation of the parameters can still be obtained. Finally an example of identifying a viscoelastic system is given to show the effectiveness of the aforementioned method.展开更多
Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method br...Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.展开更多
In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is respons...In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is responsible for capturing original signals from sensors. The software part is a virtual oscilloscope based on LabWindows/CVI （C vitual instrument）, which not only has the functions of traditional oscilloscope but also can analyze and process vibration signals in special ways. The experimental results show that the designed system is stable, reliable and easy to be operated, which can meet practical requirements.展开更多
This paper describes a technology of dynamic display moving image by computer monitor,which is initially used in the design of tool detection system. The paper presents the hardware and software principie and edge det...This paper describes a technology of dynamic display moving image by computer monitor,which is initially used in the design of tool detection system. The paper presents the hardware and software principie and edge detection process. The way of marking edge point coordinates and stability of moving image also is analyzed. The method reforms the conventional design of the 2-D vision detection system. Moreover,it facilitates the design of the systematic mechanical construction,is convenient to compile instrument systemsoftware,and realizes to detect and track display image simultaneously. By the work,the tool detection system is improved to practical application.展开更多
Threshold decision is an important function of nuclear instrument control system based on physical parameters threshold decision. Because the conventional decision methods lack correlation with time and conditions, by...Threshold decision is an important function of nuclear instrument control system based on physical parameters threshold decision. Because the conventional decision methods lack correlation with time and conditions, by analyzing the existing methods, some optimized methods are adopted. Considering safety, those methods are improved in data processing algorithms, floating threshold with multiple values, association with specific working condition, etc. These measures im- prove the nuclear instrument control system in fault tolerance and fault diagnosis, especially, the shutdown number of nucle- ar power plant decreases.展开更多
An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, clo...An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.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
Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical mo...Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical monitoring system is able to provide adequate warning to underground personnel prior to any unexpected major geotechnical failure. This paper reviews the conventional geotechnical monitoring sensors and the emerging Fibre Optic Sensing(FOS) techniques, pointing out their unique features and major differences. Recent advances in various FOS based monitoring systems, including Brillouin time domain distributed optical sensors and fibre Bragg grating(FBG) sensors, are investigated through a critical review of the laboratory studies and field applications used for underground geotechnical monitoring. Particular emphasis is given to fibre packaging, temperature compensation, installation methods and instrumentation performance in the underground environment. A detailed discussion of the advantages and limitations of each FOS monitoring system is also presented in this paper.展开更多
In order to measure the Universal Time(UT1)in real time,National Time Service Center(NTSC)has built a VGOS-like(VLBI Global Observing System)broadband VLBI network,which includes three13-m radio telescopes located in ...In order to measure the Universal Time(UT1)in real time,National Time Service Center(NTSC)has built a VGOS-like(VLBI Global Observing System)broadband VLBI network,which includes three13-m radio telescopes located in Jilin,Sanya and Kashi,and a data analysis center in Xi’an.Each station is equipped with a highly stable hydrogen atomic clock and a self-developed VLBI backend,and is colocated with two GPS receivers.This VGOS-like VLBI network may play an important role in improving the Chinese broadband VLBI technology and making valuable contributions to domestic VLBI measurements of UT1.In this paper,we introduce the specifications of this VLBI network,and present the UT1 measurements at C-band conducted in 2018 using the Jilin-Kashi baseline of this network.The comparisons between our UT1 estimates and those provided by IERS suggest that the NTSC VLBI network is capable to determine UT1 accurate at the level of 58.8μs.展开更多
As the number of array elements and bandwidth increase,the design challenges of the Phased Array Feed(PAF)front-end and its signal processing system increase.Aiming at the ng-PAF of the 110 m radio telescope,this arti...As the number of array elements and bandwidth increase,the design challenges of the Phased Array Feed(PAF)front-end and its signal processing system increase.Aiming at the ng-PAF of the 110 m radio telescope,this article introduces the concept of fully digital receivers and attempts to use Radio Frequency System-on-Chip(RFSo C)technology to digitize close to the feed array,reduce the complexity and analog components of the front-end,and improve the fidelity of the signals.The article discusses the digital beamforming topology and designs a PAF signal processing experimental system based on RFSo C+GPU hybrid architecture.The system adopts a ZCU111board to design RF-direct digitization and preprocessing front-end,which can sample eight signals up to 2.048GSPS,12 bit,channelize the signals into 1024 chunks,then reorder into four data streams and select one of the 256MHz frequency bands to output through four 10 Gb links.A GPU server is equipped with four RTX 3090 GPUs running four HRBF_HASHPIPE instances,each receiving a 64 MHz bandwidth signal for high-throughput realtime beamforming.The experimental system uses a signal generator to emulate Sa-like signals and propagates through rod antennas,which verifies the effectiveness of the beamforming algorithm.Performance tests show that after algorithm optimization,the average processing time for a given 4 ms data is less than 3 ms in the four-GPU parallel processing mode.The RFSo C integrated design shows significant advantages in power consumption and electromagnetic radiation compared with discrete circuits according to the measurement results.展开更多
A drilling process monitor （DPM） for ground characterization of weathered granite is presented. The monitor is portable and can be mounted on a hydraulic rotary drilling rig to record various drilling parameters in ...A drilling process monitor （DPM） for ground characterization of weathered granite is presented. The monitor is portable and can be mounted on a hydraulic rotary drilling rig to record various drilling parameters in real time during normal subsurface investigation. The identification method for dominative and subsidiary interfaces has been established. The study reveals that the monitored drilling parameters are dependent on geotechnical materials and can be further applied to characterize ground interfaces. The t-test between manual logging and DPM logging has been carried out. The results show that the DPM has high accuracy in interfaces detection and well agreement with the manual logging. The findings show that the device and data analysis method are of potential application in subsurface drilling exploration in weathered granites. It also seems to have prospective uses in the determination of orebody boundary as well as in the detection of geohazards.展开更多
Abstract In this paper, a cascade acceleration feedback control （AFC） enhanced by a disturbance observa- tion and compensation （DOC） method is proposed to improve the tracking precision of telescope systems. Teles...Abstract In this paper, a cascade acceleration feedback control （AFC） enhanced by a disturbance observa- tion and compensation （DOC） method is proposed to improve the tracking precision of telescope systems. Telescope systems usually suffer some uncertain disturbances, such as wind load, nonlinear friction and other unknown disturbances. To ensure tracking precision, an acceleration feedback loop which can in- crease the stiffness of such a system is introduced. Moreover, to further improve the tracking precision, we introduce the DOC method which can accurately estimate the disturbance and compensate it. Furthermore, the analysis of tracking accuracy used by this method is proposed. Finally, a few comparative experimental results show that the proposed control method has excellent performance for reducing the tracking error of a telescope system.展开更多
The 85-cm telescope at Xinglong station is a prime focus system that operates well with high science outputs. The telescope has been upgraded since 2014 with a new corrector, and new filters and camera, which are prov...The 85-cm telescope at Xinglong station is a prime focus system that operates well with high science outputs. The telescope has been upgraded since 2014 with a new corrector, and new filters and camera, which are provided by Beijing Normal University. The filter set is the Johnson-Cousins UBV RI system. We report the test results of the new system including bias, dark current, linearity, gain and readout noise of the CCD camera. Then we derive accurate instrumental calibration coefficients in UBV RI bands with Landolt standard stars during photometric nights. Finally, we give the limiting magnitudes with various exposure times and signal-to-noise ratios for observers as references.展开更多
Servo pressure pulse testing equipment uses servo-hydraulic technology to build the model of hydraulic system. By improving measurement and control system, the equipment accomplishes signal acquisition, data processin...Servo pressure pulse testing equipment uses servo-hydraulic technology to build the model of hydraulic system. By improving measurement and control system, the equipment accomplishes signal acquisition, data processing and process con- trol. LabVIEW and programmable logic controller （PLC） are used to carry out the hardware configuration and software de- velopment. The system can communicate between LabVIEW and PLC by virtual instrumentation software architecture （VI- SA） and run automatically in accordance with setting commands. Therefore, accuracy and performance of the equipment are improved.展开更多
基金funded by the National Key Research and Development Program of China under Nos.2023YFA1608200&2020YFC2201703the National Natural Science Foundation of China(NSFC,Grant No.12020101002)the Natural Science Foundation of China for the youth under No.12103093。
文摘The proposed design of a microwave superconducting kinetic inductance detector(MKID)array readout system characterizes the performance of MKIDs through a digital homodyne frequency mixing architecture.Meanwhile,the readout system is implemented using a frequency division multiplexing circuit system,coupled with an FFT design to enable the readout of MKID arrays.The system is characterized by its compact size,low cost,portability,and ease of further development.Together,these features have significant implications for the design and readout of terahertz MKID arrays,while simultaneously advancing both the theoretical and practical aspects of MKID technology.
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.11427901)。
文摘The infrared Fourier transform spectrometer needs a cold view field diaphragm to reduce stray radiation.For an infrared spectrometer with linear array detectors,the part of the view field diaphragm where the light passes can be regarded as a slit.If the infrared detectors are small in size,the width of the slit is also small,which will cause serious diffraction phenomena.If the widths of the view field diaphragm and the optical system are designed by geometric optics theory,the diffraction light cannot be fully received by the detectors,which will cause energy loss.Expanding the width of the view field diaphragm will introduce stray radiation.Meanwhile,spectrometer follow-up optics should be set in cold environments to reduce the infrared background of the instrument.Optical materials have different thermal characteristics,the optical and mechanical structures will deform at lowtemperature,and the cold view field diaphragm is installed at room temperature,so it is impossible to guarantee that the cold view field diaphragm remains in its design position when working at low-temperature.This paper solves the above problems by designing an adjustable cold view field diaphragm installed in its cryogenic vacuum chamber.The width and position of the view field diaphragm can be adjusted when working in cold temperatures,without opening the cryogenic vacuum chamber.Contrasting the interference signal obtained by the detectors in the adjustment process,the system can get the most suitable width and position of the cold view field diaphragm.The above works are based on the spectrometer used in the study named Accurate Infrared Magnetic Field Measurements of the Sun.
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.
基金supported by the National Key R&D Program of China(grant Nos.2023YFA1609700,2023YFA1608304,and2023YFA1608303)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0550103)+1 种基金the National Natural Science Foundation of China(NSFC,Nos.12090040 and 12090041)supported from the Strategic Pioneer Program of the Astronomy Large-Scale Scientific Facility,Chinese Academy of Sciences,and the Science and Education Integration Funding of the University of Chinese Academy of Sciences。
文摘The Mini-SiTian project,which is a pathfinder for the SiTian project,utilizes three 30 cm telescopes equipped with commercial CMOS cameras(ZWO ASI6200MM Pro)to simulate a large-area time-domain survey.Due to the avoidance of the traditional mechanical shutter,the CMOS camera is favorable in time-domain survey projects.In the future,the SiTian telescope array will employ a two-by-two scientific-grade mosaic CMOS camera to survey a10,000 degree square area every 30 minutes.Therefore,the performance of CMOS directly determines the detection capability of SiTian telescopes for transient sources,and a comprehensive understanding of the performance of CMOS cameras is crucial.In this research,laboratory testing was conducted to thoroughly evaluate three cameras by assessing several critical parameters,including bias stability,dark current,pixel anomalies,linearity,gain,and read noise.We find exceptional short-term bias stability with standard deviations below 0.02 ADU,negligible dark current of approximately 0.002 e-pixel^(-1)s^(-1)at 0℃,and excellent linearity with nonlinearity consistently below±0.5%,and a small proportion(0.06%-0.08%)of pixels with anomalous responses.Furthermore,our analysis demonstrates uniform gain values across all cameras,ranging from 0.252 to 0.255 e-ADU^(-1),with low readout noise,measured to be below 1.6 e-using conventional methods.We also propose a novel method for pixel-level gain and read noise calculation for CMOS sensors,which revealed a narrow gain distribution and a low median read noise of 1.028 e-for one of the cameras.The laboratory testing of the ZWO ASI6200MM Pro cameras indicates their potential to meet the requirements of time-domain surveys for the Mini-SiTian project.
基金Supported by National Key R&D Program of China(grant No.2023YFA1608304)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0550103)National Natural Science Foundation of China(NSFC,grant No.11903054)。
文摘The SiTian Project represents a groundbreaking initiative in astronomy,aiming to deploy a global network of telescopes,each with a 1 m aperture,for comprehensive time-domain sky surveys.The network's innovative architecture features multiple observational nodes,each comprising three strategically aligned telescopes equipped with filters.This design enables three-color(g,r,i)channel imaging within each node,facilitating precise and coordinated observations.As a pathfinder to the full-scale project,the Mini-SiTian Project serves as the scientific and technological validation platform,utilizing three 30 cm aperture telescopes to validate the methodologies and technologies planned for the broader SiTian network.This paper focuses on the development and implementation of the Master Control System(MCS),and the central command hub for the Mini-SiTian Array.The MCS is designed to facilitate seamless communication with the SiTian Brain,the project's central processing and decisionmaking unit,while ensuring accurate task allocation,real-time status monitoring,and optimized observational workflows.The system adopts a robust architecture that separates front-end and back-end functionalities.A key innovation of the MCS is its ability to dynamically adjust observation plans in response to transient source alerts,enabling rapid and coordinated scans of target sky regions.The paper provides an in-depth analysis of the system's internal components,including the communication system,which is critical for seamless network operation.Extensive testing has validated the functionality,reliability,and compatibility of these components within the overall system architecture.The successful deployment of the MCS in managing the Mini-SiTian Array has demonstrated its practicality and efficacy in collaborative observation and distributed control.By simplifying cluster management and ensuring data integrity,the MCS represents a significant advancement in astronomical observation control systems.Its scalable and adaptable design not only supports the future expansion of the SiTian network but also provides a blueprint for other large-scale telescope arrays,marking a transformative step forward in time-domain astronomy.
基金supported by Sino Probe Project(Sino Probe-09-02,201011079)Development Project of National Key Scientific Equipment(No.ZDYZ2012-1-05)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA14050100)
文摘To test the performance of the Chinese whole-surface electromagnetic prospecting （SEP） system, system integrations, instrument performances, and large-scale production viabilities in Liaoning province and Inner Mongolia were measured via extensive field tests. Resultant electric fields, magnetic fields, apparent resistivities, impedance phases, and inversion profiles compared favorably with results of commercial equipment from other countries. The inversion results agreed well with the geologic information from boreholes. Field tests showed that the SEP system is stable, reliable, lightweight, and easy to operate, making it suitable and ready for real-field exploration.
文摘The state-space representation of linear time-invariant (LTI) fractional order systems is introduced, and a proof of their stability theory is also given. Then an efficient identification algorithm is proposed for those fractional order systems. The basic idea of the algorithm is to compute fractional derivatives and the filter simultaneously, i.e., the filtered fractional derivatives can be obtained by computing them in one step, and then system identification can be fulfilled by the least square method. The instrumental variable method is also used in the identification of fractional order systems. In this way, even if there is colored noise in the systems, the unbiased estimation of the parameters can still be obtained. Finally an example of identifying a viscoelastic system is given to show the effectiveness of the aforementioned method.
文摘Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.
基金National Natural Science Foundation of China(No.61302159,61227003,61301259)Natural Science Foundation of Shanxi Province(No.2012021011-2)The Project Sponsored by Scientific Research for the Returned Overseas Chinese Scholars,Shanxi Province(No.2013-083)
文摘In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is responsible for capturing original signals from sensors. The software part is a virtual oscilloscope based on LabWindows/CVI （C vitual instrument）, which not only has the functions of traditional oscilloscope but also can analyze and process vibration signals in special ways. The experimental results show that the designed system is stable, reliable and easy to be operated, which can meet practical requirements.
文摘This paper describes a technology of dynamic display moving image by computer monitor,which is initially used in the design of tool detection system. The paper presents the hardware and software principie and edge detection process. The way of marking edge point coordinates and stability of moving image also is analyzed. The method reforms the conventional design of the 2-D vision detection system. Moreover,it facilitates the design of the systematic mechanical construction,is convenient to compile instrument systemsoftware,and realizes to detect and track display image simultaneously. By the work,the tool detection system is improved to practical application.
基金Research Project of Hunan Province Education Department(No.14C0972)
文摘Threshold decision is an important function of nuclear instrument control system based on physical parameters threshold decision. Because the conventional decision methods lack correlation with time and conditions, by analyzing the existing methods, some optimized methods are adopted. Considering safety, those methods are improved in data processing algorithms, floating threshold with multiple values, association with specific working condition, etc. These measures im- prove the nuclear instrument control system in fault tolerance and fault diagnosis, especially, the shutdown number of nucle- ar power plant decreases.
基金Project(51274250)supported by the National Natural Science Foundation of ChinaProject(2012BAK09B02-05)supported by the National Key Technology R&D Program during the 12th Five-year Plan of China
文摘An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.
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.
文摘Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical monitoring system is able to provide adequate warning to underground personnel prior to any unexpected major geotechnical failure. This paper reviews the conventional geotechnical monitoring sensors and the emerging Fibre Optic Sensing(FOS) techniques, pointing out their unique features and major differences. Recent advances in various FOS based monitoring systems, including Brillouin time domain distributed optical sensors and fibre Bragg grating(FBG) sensors, are investigated through a critical review of the laboratory studies and field applications used for underground geotechnical monitoring. Particular emphasis is given to fibre packaging, temperature compensation, installation methods and instrumentation performance in the underground environment. A detailed discussion of the advantages and limitations of each FOS monitoring system is also presented in this paper.
基金supported by the National Natural Science Foundation of China(Grant Nos.11703033,11673051,11603001 and U1831136)the West Light Foundation of the Chinese Academy of Sciences(XAB2016A06)supported by the 100 Talents Project of the Chinese Academy of Sciences(CAS)。
文摘In order to measure the Universal Time(UT1)in real time,National Time Service Center(NTSC)has built a VGOS-like(VLBI Global Observing System)broadband VLBI network,which includes three13-m radio telescopes located in Jilin,Sanya and Kashi,and a data analysis center in Xi’an.Each station is equipped with a highly stable hydrogen atomic clock and a self-developed VLBI backend,and is colocated with two GPS receivers.This VGOS-like VLBI network may play an important role in improving the Chinese broadband VLBI technology and making valuable contributions to domestic VLBI measurements of UT1.In this paper,we introduce the specifications of this VLBI network,and present the UT1 measurements at C-band conducted in 2018 using the Jilin-Kashi baseline of this network.The comparisons between our UT1 estimates and those provided by IERS suggest that the NTSC VLBI network is capable to determine UT1 accurate at the level of 58.8μs.
基金funded by the National Natural Science Foundation of China(NSFC,Grant No.12073066)the National Key R&D Program of China under No.2021YFC2203502+3 种基金the Youth Innovation Promotion Association of CAS under No.2020063the NSFC(Grant Nos.61931002,12073067 and 11973077)the Natural Science Foundation of Xinjiang Uygur Autonomous Region under No.2021D01E07partly supported by the Operation,Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments,budgeted from the Ministry of Finance of China(MOF)and administrated by the Chinese Academy of Sciences(CAS)。
文摘As the number of array elements and bandwidth increase,the design challenges of the Phased Array Feed(PAF)front-end and its signal processing system increase.Aiming at the ng-PAF of the 110 m radio telescope,this article introduces the concept of fully digital receivers and attempts to use Radio Frequency System-on-Chip(RFSo C)technology to digitize close to the feed array,reduce the complexity and analog components of the front-end,and improve the fidelity of the signals.The article discusses the digital beamforming topology and designs a PAF signal processing experimental system based on RFSo C+GPU hybrid architecture.The system adopts a ZCU111board to design RF-direct digitization and preprocessing front-end,which can sample eight signals up to 2.048GSPS,12 bit,channelize the signals into 1024 chunks,then reorder into four data streams and select one of the 256MHz frequency bands to output through four 10 Gb links.A GPU server is equipped with four RTX 3090 GPUs running four HRBF_HASHPIPE instances,each receiving a 64 MHz bandwidth signal for high-throughput realtime beamforming.The experimental system uses a signal generator to emulate Sa-like signals and propagates through rod antennas,which verifies the effectiveness of the beamforming algorithm.Performance tests show that after algorithm optimization,the average processing time for a given 4 ms data is less than 3 ms in the four-GPU parallel processing mode.The RFSo C integrated design shows significant advantages in power consumption and electromagnetic radiation compared with discrete circuits according to the measurement results.
基金This work is financially supported by the Research Grant Council of HKSAR Government and Hong Kong Jockey Club CharitiesTrust.
文摘A drilling process monitor （DPM） for ground characterization of weathered granite is presented. The monitor is portable and can be mounted on a hydraulic rotary drilling rig to record various drilling parameters in real time during normal subsurface investigation. The identification method for dominative and subsidiary interfaces has been established. The study reveals that the monitored drilling parameters are dependent on geotechnical materials and can be further applied to characterize ground interfaces. The t-test between manual logging and DPM logging has been carried out. The results show that the DPM has high accuracy in interfaces detection and well agreement with the manual logging. The findings show that the device and data analysis method are of potential application in subsurface drilling exploration in weathered granites. It also seems to have prospective uses in the determination of orebody boundary as well as in the detection of geohazards.
基金supported by the Quantum Communication Project,one of the Strategic Pilot Projects,Chinese Academy of Sciences
文摘Abstract In this paper, a cascade acceleration feedback control （AFC） enhanced by a disturbance observa- tion and compensation （DOC） method is proposed to improve the tracking precision of telescope systems. Telescope systems usually suffer some uncertain disturbances, such as wind load, nonlinear friction and other unknown disturbances. To ensure tracking precision, an acceleration feedback loop which can in- crease the stiffness of such a system is introduced. Moreover, to further improve the tracking precision, we introduce the DOC method which can accurately estimate the disturbance and compensate it. Furthermore, the analysis of tracking accuracy used by this method is proposed. Finally, a few comparative experimental results show that the proposed control method has excellent performance for reducing the tracking error of a telescope system.
基金support from the staff at the Xinglong 85-cm telescopesupport from the National Natural Science Foundation of China(NSFC)through grant 11673003+3 种基金the National Basic Research Program of China(973 program,2014CB845700)partially supported by the Open Project Program of the Key Laboratory of Optical Astronomy(National Astronomical Observatories)NSFC under Grant Nos.11403088 and 11273051(Xinjiang Astronomical Observatory)Chinese Academy of Sciences and Department of Astronomy,Beijing Normal University
文摘The 85-cm telescope at Xinglong station is a prime focus system that operates well with high science outputs. The telescope has been upgraded since 2014 with a new corrector, and new filters and camera, which are provided by Beijing Normal University. The filter set is the Johnson-Cousins UBV RI system. We report the test results of the new system including bias, dark current, linearity, gain and readout noise of the CCD camera. Then we derive accurate instrumental calibration coefficients in UBV RI bands with Landolt standard stars during photometric nights. Finally, we give the limiting magnitudes with various exposure times and signal-to-noise ratios for observers as references.
基金High Level Talented Person Funded Project of Hebei Province(No.C2013005003)Excellent Experts for Going Abroad Training Program of Hebei Province(No.10215601D)
文摘Servo pressure pulse testing equipment uses servo-hydraulic technology to build the model of hydraulic system. By improving measurement and control system, the equipment accomplishes signal acquisition, data processing and process con- trol. LabVIEW and programmable logic controller （PLC） are used to carry out the hardware configuration and software de- velopment. The system can communicate between LabVIEW and PLC by virtual instrumentation software architecture （VI- SA） and run automatically in accordance with setting commands. Therefore, accuracy and performance of the equipment are improved.
