日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM11] Dynamics of Magnetosphere and Ionosphere

2019年5月29日(水) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:中溝 葵(情報通信研究機構 電磁波研究所)、尾崎 光紀(金沢大学理工研究域電子情報学系)、藤本 晶子(九州工業大学)、堀 智昭(名古屋大学宇宙地球環境研究所)

[PEM11-P27] Fine-scale visualization of aurora in a wide area using color digital camera images from the International Space Station

*南條 壮汰1穂積 裕太1細川 敬祐1 (1.電気通信大学)

キーワード:オーロラ、国際宇宙ステーション

Various ground-based and space-based imagers have been used to observe aurora borealis and australis. So far, however, it has been difficult to observe the detailed spatial structure of auroras in a wide area with sufficient spatial and temporal resolution. Since the photographs taken from the International Space Station (ISS) have sufficient spatial and temporal resolution, it is possible to visualize the fine-scale structures of aurora in a wide area. A calibration of imaging parameters of the photographs using star lights was proposed by a previous research. The accuracy in the timestamp was not guaranteed by the method based on the star lights because the position of the star lights in the image did not change with elapsed time. Thus, it is still difficult to use the mapped data for studying fast variations of aurora, for example pulsating aurora (PsA). Therefore, in this study, we calibrated the images from the ISS using city lights which change their apparent positions with elapsed time. In order to validate the calibration method using city light positions, we mapped two PsA events in the photographs to the geographical coordinate, and compared with those from ground-based all-sky imagers in Alaska and Canada. We found that the approximate shape of discrete aurora and the temporal variation of PsA derived from the ISS images are consistent with those from the ground-based observation. The accuracy in the timestamp is less than 0.5 sec and that in space in the direction perpendicular to the line of sight of the camera is within 5 km. In the presentation, we will also address how the mapped full-color images can be used for studies of PsA in the future work.