The non-uniform pattern in full-disc vector magnetograms and its correction

	The non-uniform pattern in full-disc vector magnetograms and its correction
	Wang, Xiaofan; Su, Jiangtao; Zhang, Hongqi
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2008-07-11
卷号	387 期号:4 页码:1463-1469
关键词	sun : activity sun : magnetic fields sun : photosphere
英文摘要	The Solar Magnetism and Activity Telescope (SMAT) has been operational at Huairou Solar Observing Station since the end of 2005. Its scientific projects are the observational study of full-disc vector magnetic field and H alpha chromospheric activities. In this paper, the Fourier low-frequency passing filter and the large-scale polynomials fit methods have been employed to analyse and remove the non-uniform pattern (NUP) in the full-disc Stokes V image. These methods are useful to effectively improve the quality of SMAT's data. The following main results have been obtained. (1) An intrinsic large-scale spatial distribution of NUP appears in SMAT's full-disc Stokes V image and its average amplitude accounts for 2 per cent of sunspots' field of kG. (2) NUP is testified as instrumental polarization through data reduction and observational explanation (passband shift). There are pseudo-passband shift in the wide field of view of SMAT due to NUP, and the maximum shifting value from the solar disc centre to the solar disc limb is 0.12 angstrom. (3) As an example, after removing SMAT's NUP in the Stokes V image, the correlation coefficients of the magnetograms become 78 per cent between SMAT and MDI (Michelson Doppler Imager project) on the SOHO (Solar and Heliospheric Observatory) satellite, and 92 per cent between SMAT and the SMFT (Solar Magnetic Field Telescope) at Huairou.
收录类别	SCI
语种	英语
WOS记录号	WOS:000257706200009
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/7422]
专题	国家天文台_太阳物理研究部
作者单位	Chinese Acad Sci, Natl Astron Observatories, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Wang, Xiaofan,Su, Jiangtao,Zhang, Hongqi. The non-uniform pattern in full-disc vector magnetograms and its correction[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2008,387(4):1463-1469.
APA	Wang, Xiaofan,Su, Jiangtao,&Zhang, Hongqi.(2008).The non-uniform pattern in full-disc vector magnetograms and its correction.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,387(4),1463-1469.
MLA	Wang, Xiaofan,et al."The non-uniform pattern in full-disc vector magnetograms and its correction".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 387.4(2008):1463-1469.