research introduction: Relative reachable domain for spacecraft under uncertainty of time-varying atmospheric density
日本語字幕有り
- Nayu Nonomiya, Yasuhiro Yoshimura, Toshiya Hanada, Relative reachable domain for spacecraft under uncertainty of time-varying atmospheric density
近年、低軌道（LEO）では衛星の数が急増し、衝突回避や安全な運用が重要な課題となっています。本研究では、衛星同士の相対運動が不確かさを含む状況でどの範囲に到達しうるかを示す「相対可到達領域（RRD: Relative Reachable Domain）」の解析手法を提案しました。従来の研究では空気抵抗の影響が無視されていましたが、本研究ではdifferential drag（衛星ごとの形状・質量の違いによる大気抵抗差）を考慮しました。数値シミュレーションの結果、大気密度の10～30%の不確かさでも相対軌道の広がりに大きく影響し、無視すると衝突リスクを過小評価することが示されました。また、提案手法はモンテカルロ解析でも妥当性が確認され、低軌道での衛星運用安全性を高める有効な解析枠組みとして期待されます。
In recent years, the number of satellites in low Earth orbit (LEO) has rapidly increased, making collision avoidance and safe operations critical challenges. This study proposes an analytical method for the "Relative Reachable Domain (RRD)," which represents the range that satellites can reach in their relative motion under conditions involving uncertainty. While previous research neglected the effects of atmospheric drag, this study accounts for differential drag (differences in atmospheric resistance due to variations in shape and mass between satellites). Numerical simulation results demonstrated that even 10–30% uncertainty in atmospheric density significantly affects the spread of relative orbits, and ignoring this leads to underestimation of collision risk. Furthermore, the proposed method's validity was confirmed through Monte Carlo analysis, and it is expected to serve as an effective analytical framework for enhancing satellite operational safety in low Earth orbit.