講演情報
[PPS03-P12]High Degree Products of Thermal Infrared Imager onboard Hayabusa2
*荒井 武彦1、出村 裕英2、岡田 達明4、田中 智4、坂谷 尚哉4、嶌生 有理4、千秋 博紀3、神山 徹5、石崎 拓也4、金丸 仁明7、関口 朋彦6 (1.前橋工科大学、2.会津大学、3.千葉工業大学、4.宇宙航空研究開発機構、5.産業技術総合研究所、6.北海道教育大学、7.東京大学)
キーワード：
はやぶさ２、中間赤外カメラ、熱慣性、高次プロダクト
The thermal infrared imager (TIR) onboard the Hayabusa2 spacecraft observed the surface temperature of asteroid 162173 Ryugu during 2018 and 2019. TIR derives the surface thermophysical properties and reveals the surface thermal evolution and the origin of their accumulation process. Thermal inertia is a key index for estimating surface thermophysical properties. This index is critical for evaluating the surface's physical condition, such as density and porosity. However, surface roughness under the spatial resolution of TIR confuses the estimation of the thermal inertia. The observed surface brightness temperature of TIR was globally flattened due to the roughness. Therefore, we need a surface thermophysical model, including the roughness model, to derive the accurate thermal inertia. We used the shape model of Ryugu with Gaussian random numbers as the roughness model. We compared the observed image with the anticipated images derived from the thermophysical model with roughness and determined the thermal inertia maps. In this study, we introduce the high-degree products of the TIR data, such as shape model projection maps (Level 3) and thermal inertia maps (Level 4).