*Kazushi Asamura¹, Manabu Shimoyama², Yoshifumi Futaana², Yoshizumi Miyoshi³, Takeshi Sakanoi⁴, Yoshifumi Saito¹ (1.Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 2.Swedish Institute of Space Physics, 3.Nagoya University, 4.Tohoku University)