Chinese sunspot drawings and their digitization–(Ⅱ)accuracy analysis for digitized sunspot hand-drawing records of Yunnan Observatories  

作　　者：Yang Peng Xiao-Yu Luo Shu-Guang Zeng Lin-Hua Deng Sheng Zheng Gang-Hua Lin Yu-Lin Cheng Jin-Ping Tao Yong-Li Feng 

机构地区：[1]College of Science,China Three Gorges University,Yichang 443002,China [2]Yunnan Observatories,Chinese Academy of Sciences,Kunming 650216,China [3]National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [4]Chongqing University of Arts and Sciences,Chongqing 402160,China

出　　处：《Research in Astronomy and Astrophysics》2020年第4期156-162,共7页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.U1731124,U1531247,11427901 and 11873089);the special foundation work of the Ministry of Science and Technology of China(Grant No.2014FY120300);the 13th Five-year Informatization Plan of Chinese Academy of Sciences(Grant No.XXH13505–04);the Youth Innovation Promotion Association CAS.The hand-drawing historic。

摘　　要：Sunspots are the most striking and easily observed magnetic structures of the Sun,and statistical analysis of solar historical data could reveal a wealth of information on the long-term variation of solar activity cycle.The hand-drawn sunspot records of Yunnan Observatories,Chinese Academy of Sciences have been accumulating for more than 60 years,and nearly 16000 images have been preserved.In the future,the observation mode of recording sunspots by hand-drawing will be replaced inevitably by digital images observed either at ground or in space.To connect the hand-drawn sunspot data and the purely digital sunspot data in future,it is necessary to analyze the systematic errors of the data which are observed by the two observation modes in the period of transition.In this paper,we choose 268 round sunspots(Htype in modified Zurich sunspot classification)from the drawing of Yunnan Observatories to compare their positions and areas with the CCD observations made by Helioseismic and Magnetic Imager(HMI)on board Solar Dynamic Observatory(SDO)and Global Oscillation Network Group(GONG).We find that the latitude and longitude accuracy of hand-drawn sunspot are within-0.127 and 2.29 degree respectively,and the area accuracy is about 16.36 sunspot unit(μHem).Systematic errors apparently decrease with large sunspot.

关 键 词：SUNSPOTS methods:data analysis techniques:image processing 

分 类 号：P182.41[天文地球—天文学]