Summary: | 碩士 === 國立成功大學 === 太空與電漿科學研究所 === 104 === FORMOSAT-3/COSMIC satellites use radio occultation and Abel inversion to observe the vertical electron density profile. The method assumes the density of the Earth is spherically symmetric. But the assumption may not correspond to real ionospheric situations. Therefore, this method of observations may lead to inaccurate results.
This study aims to find out the factor that is important in affecting the discrepancy between the observed TEC by FORMOSAT-3/COSMIC and the radar observatory. We apply the observed electron density profiles to calculate TEC.
Parameters such as F10.7, Dst index, Kp index, AE index, AU index, AL index, local time and angle between the satellite and radar observations are examined as possible factors for the discrepancy. Finally, this study finds the discrepancy in TEC between FORMOSAT-3/COSMIC and radar observations is mainly due to westward electrojet and eastward electrojet. The secondary reason is the angle between the observation locations of FORMOSAT-3/COSMIC and the radar observatory subtended at the center of the Earth. We find that the larger this angle, the larger the percentage error for the FORMOSAT-3/COSMIC observations.
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