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Development and application of high-precision multifunction astronomical plate digitizers in China

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Astronomical Techniques and Instruments 2024年第1期1卷 71-75页

作者： Meiting Yang Yong Yu Liangliang Wang Zhengjun Shang Changshun Liu Lixin Zheng Zhendong Chen Jing Yang Dongmei Da Shan Dong Shiyin Shen Zhenghong Tang Jianhai Zhao Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China

Before charge-coupled device detectors became widely employed in observational astronomy,for more than a hundred years,the main detection method was photography on astronomical glass plates.Recently,in order to preserve these historical data and maintain their usability,the International Astronomical Union has appealed to all countries for global digitization of astronomical plates by developing or adopting advanced digitization technology.Specialized digitizers with high precision and high measuring speed represent key equipment for this task.The Shanghai Astronomical Observatory and the Nishimura Co.,Ltd in Japan cooperated between 2013 and 2016 to develop the first Chinese high-precision astronomical plate digitizer,which was then used for complete digitization of all nighttime-observation astronomical plates in China.Then,in 2019–2021,the Shanghai Astronomical Observatory independently developed new models of plate digitizers that enabled countries such as Uzbekistan and Italy to digitize their astronomical plates.Additionally,a new high-precision and multifunction digitizer was also used to digitize valuable microscope slides from the Shanghai Natural History Museum,providing a successful example of cross-domain application of high-precision digitization technology.

关键词： Astrometry-instrumentation detectors-methods Data analysis-techniques Image processing

Faint Space Debris Detection Algorithm Based on Small Aperture Telescope Detection System

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Research in Astronomy and Astrophysics 2022年第10期22卷 24-38页

作者： Ping Jiang Chengzhi Liu Zhe Kang Wenbo Yang Zhenwei Li Changchun Observatory of National Astronomical Observatories Chinese Academy of SciencesChangchun 130117China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Space Object&Debris Observation PMOCASNanjing 210008China

Ground-based optical observation has unique advantages in space target observation.However,due to the weak light-gathering ability of small-aperture optoelectronic observation telescopes,the space debris in the image is weak and easily drowned in noise.In order to solve the above problems,we use digital image processing technology to extract faint space debris.We propose a high detection rate space debris automatic extraction algorithm,aiming to automatically detect space debris.We first establish a new space target description model.Our algorithm is mainly divided into two stages.The purpose of the first stage is to reduce the influence of a large number of stars.We perform wavelet transform and guided filtering for three consecutive frames,and the reconstructed wavelet that takes the median value can achieve the effect of eliminating stars.In the second stage,we adopt the method of robust principal component analysis and attribute the problem of target detection to the problem of separating the target and background of a single frame of image.After a large number of experimental results analysis,it is proved that the algorithm can effectively detect faint debris in the monitoring system of small aperture telescope,and has high precision and low computational complexity.

关键词： instrumentation detectors-methods data analysis-methods observational

Nonlinear Variability Observed with Insight-HXMT in MAXI J1820+070 and MAXI J1535-571

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Research in Astronomy and Astrophysics 2023年第8期23卷 346-354页

作者： Qi Ding Long Ji Qing-Cui Bu Tiekuang Dong Jin Chang Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210033China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519000China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard KarlsUniversitätSand 1D-72076 TübingenGermany National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

We present the timing analysis of the nonlinear variability in two black hole low mass X-ray binaries MAXI J1820+070 and MAXI J1535-571 by using the bicoherence,a measure of phase coupling at different Fourier frequencies.We found different patterns,e.g.,“cross”and“hypotenuse,”for LFQPOs in different outburst states.When they can be clearly distinguished,bicoherence patterns are similar over a wide energy range of 1–100 keV.It is intriguing that in some type-C QPOs we found the patterns that are normally observed in type-B QPOs.On the contrary,the“hypotenuse”pattern,a characteristic of type-C QPOs,was detected in a type-B QPO.This suggests that different types of QPOs may originate from similar underlying mechanisms.In addition,we speculate that the nonlinear variability may be a promising approach to disentangle distinct QPO models which assume different interactions between the broadband noise and QPO components.

关键词： black hole physics-instrumentation detectors-methods data analysis-X-rays binaries

Preliminary Simulation and Manufacture of a 40-element PAF Prototype for FAST

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Research in Astronomy and Astrophysics 2023年第8期23卷 153-163页

作者： Jun Wang Chengjin Jin Bo Peng Yan Zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

This paper presents the preliminary simulation results of the prototype 40-element phased array feed(PAF)array for the Five-hundred-meter Aperture Spherical radio Telescope(FAST)and the measurement of a manufactured single Vivaldi element.The simulation results include the characteristic of a standalone Vivaldi element.The full-wave simulation of the explicit PAF array is carried out,from which the performance of the embedded elements and the mutual coupling among the elements could be accurately inferred.The performance of the combination of the PAF and the main reflector of FAST is calculated.The results imply that the PAF combined with the FAST antenna could operate over a much wider bandwidth from 650 to 1450 MHz compared with the standalone element.The antenna temperature remains almost the same for zenith angles from 0 to 40°.From the simulation results,the PAF shows good potential to improve the performance of FAST.A measurement of a manufactured Vivaldi element is also presented.

关键词： instrumentation detectors-methods observational-telescopes

A method for aligning the plastic scintillator detector on DAMPE

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Research in Astronomy and Astrophysics 2019年第6期19卷 63-70页

作者： Peng-Xiong Ma Yong-Jie Zhang Ya-Peng Zhang Yao Li Jing-Jing Zang Xiang Li Tie-Kuang Dong Yi-Zhong Fan Shi-Jun Lei Jian Wu Yu-Hong Yu Qiang Yuan Chuan Yue Zhi-Yu Sun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China School of Astronomy and Space Science University of Science and Technology of China Hefei 230026 China Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China School of Nuclear Science and Technology Lanzhou University Lanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049 China

The Plastic Scintillator Detector(PSD) onboard the DArk Matter Particle Explorer(DAMPE)is designed to measure cosmic ray charge(Z) and to act as a veto detector for gamma ray identification.To fully exploit the charge identification potential of PSD and to enhance its capability to identify gamma ray events, we develop an alignment method for the PSD. The path length of a given track in the volume of a PSD bar is derived taking into account the shift and rotation alignment corrections. By examining energy spectra of corner-passing events and fully contained events, position shifts and rotations of all PSD bars are obtained, and are found to be on average about 1 mm and 0.0015 radian respectively. To validate the alignment method, we introduce artificial shifts and rotations of PSD bars into the detector simulation.These shift and rotation parameters can be recovered successfully by the alignment procedure. As a result of the PSD alignment procedure, the charge resolution of the PSD is improved from 4% to 8%, depending on the nuclei.

关键词： instrumentation detectors-methods data analysis