Comparison of the Vector Magnetograms taken with the SFT/MTK and the SST/KSW

We carried out a detailed comparison between the vector magnetograms obtained with the Solar Flare Telescope (SFT/MTK) of the National Astronomical Observatory of Japan and those obtained with the Sextuple Solar Telescope (SST/KSW) of the Kawaguchi Science Museum (the former name is the Kawaguchi Science World). We investigated various characteristics of the errors in the Stokes parameters for each instrument. The level of noise due to seeing effects in the SST/KSW magnetograms is higher than in the SFT/MTK magnetograms. On the other hand, we found that about 60% of the data pixels have the same sign of current helicity α in these magnetograms. We will discuss the possibility and limitations of the magnetic field studies using these magnetograms.