We use 270 pairs of vector magnetograms observed by Haleakala Stokes Polarimeter (HSP) and Solar Magnetic Field Telescope (SMFT) of Huairou Solar Observing Station from 1997 to 2000 to compare current helicity derived by these two instruments. We apply the same approach to both data sets to resolve 180∘ azimuth ambiguity and compute α coefficient of linear force-free field. After careful consideration of various aspects of both data sets, we find that in ≈80% of cases SMFT and HSP data result in the same sign of α, and the Pearson linear correlation coefficient between two data sets is rp = 0.64.
KeywordsAzimuth Linear Correlation Careful Consideration Vector Magnetograms Pearson Linear Correlation
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