[P-EM16] Dynamics of Earth's Inner Magnetosphere and Initial Results from Arase

[PEM16-P23] Statistical analysis of spacecraft charging environment in the medium earth orbit

寺岡 毅¹、*中村 雅夫¹、浅村 和史²、篠原 育²、三好 由純³、Shiang-Yu Wang⁴ (1.大阪府立大学、2.宇宙航空研究開発機構宇宙科学研究本部、3.名古屋大学宇宙地球環境研究所、4.中央研究院, 台湾)

キーワード：宇宙機表面帯電、中高度軌道、あらせ衛星

Analysis of spacecraft surface charging in the medium earth orbit (MEO) is important for spacecraft designs and operations, because the surface charging sometimes cause spacecraft anomalies due to discharging arcs. We study the surface charging environment using the Electric Field and Wave instruments (EFW) and the Helium Oxygen Proton Electron (HOPE) data of the Van Allen Probes and the Low energy Experiments (LEP) data of the ARASE satellite. We analyze the relationship between the observed spacecraft potential and the average electron temperature which show an approximate power law relationship in the geostationary earth orbit (GEO). However, we cannot find such a power law relationship in MEO. Therefore we calculate other plasma environmental parameters, for instance, from multi-temperature treatments using a discriminant analysis for the energy flux distributions. We will discuss the relationships between the spacecraft potential and these plasma environment parameters in MEO.