文献类型：期刊文献

英文题名：An Automatic Approach for Grouping Sunspots and Calculating Relative Sunspot Number on SDO/HMI Continuum Images

作者：Zhao, Cui[1];Yang, Shangbin[2,3,4];Wang, Tingmei[1];Zhao, Haiyan[1];Liu, Shiyuan[1];He, Fangyuan[1];Hu, Zhengkun[1]

通讯作者：Yang, SB[1];Yang, SB[2];Yang, SB[3]

机构：[1]Beijing Union Univ, Coll Appl Sci & Technol, Beijing 102200, Peoples R China;[2]Chinese Acad Sci, Natl Astron Observ, 20A Datun Rd, Beijing 100012, Peoples R China;[3]Univ Chinese Acad Sci, Beijing 100049, Peoples R China;[4]Key Lab Solar Act & Space Weather, Beijing 100190, Peoples R China

第一机构：北京联合大学应用科技学院

通讯机构：[1]corresponding author), Chinese Acad Sci, Natl Astron Observ, 20A Datun Rd, Beijing 100012, Peoples R China;[2]corresponding author), Univ Chinese Acad Sci, Beijing 100049, Peoples R China;[3]corresponding author), Key Lab Solar Act & Space Weather, Beijing 100190, Peoples R China.

年份：2024

卷号：167

期号：2

外文期刊名：ASTRONOMICAL JOURNAL

收录：;EI(收录号：20240037891);Scopus(收录号：2-s2.0-85182571556);WOS:【SCI-EXPANDED(收录号:WOS:001139752300001)】；

基金：The authors would like to thank the anonymous reviewers for comments and suggestions that improved the quality of this manuscript. Images and data used in this paper are provided by SDO/HMI, SIDC, and HFC, for which we are very grateful. This work is supported by the National Key R&D Program of China No. 2022YFF0503800, National Natural Science Foundation of China (grants No. 12250005, 12073040), Academic Research Projects of Beijing University (No. ZK20202204, ZK90202106, ZK90202105), the General projects of science and technology plan of Beijing Municipal Education Commission (KM20211141700), the R&D Program of Beijing Municipal Education Commission (KM201911417003, KM202211417006), and ZS2023A02.

语种：英文

摘要：The relative sunspot number is one of the major parameters for the study of long-term solar activity. The automatic calculation of the relative sunspot number is more stable and accurate as compared to manual methods. In this paper, we propose an algorithm that can detect sunspots, and divide them into groups to automatically calculate the relative sunspot number. Mathematical morphology was adopted to detect sunspots then group them. The data set used were the continuum images from SDO/HMI. The process was carried out on the overall HMI data available on the timespan from 2022 January to 2023 May with a time cadence of one day. The experimental results indicated that the method achieved high accuracy of 85.3%. It was well fitted with the international relative sunspot number provided by Solar Influences Data Analysis Center (CC = 0.91). We calculated the conversion factor K value of SDO/HMI for calculating the relative sunspots number (K = 1.03).