CAS key Laboratory of Solar Activity;
National Astronomical Observatories of Chinese Academy of Sciences;
Beijing 100101;
China;
School of Astronomy and Space Sciences;
University of Chinese Academy of Sciences;
Beijing 100049;
China;
Key Laboratory of Space Weather;
National Center for Space Weather;
China Meteorological Administration;
Beijing 100081;
China;
instrumentation; polarimeters methods; data analysis; methods:observational;