[1] Radio Atmospheric Science Center, Kyoto University, Kyoto, Japan
[2] Department of Physics and Astronomy, University of Iowa, Iowa City, IA, United States
[3] Institute for Computer Science, Kyoto Sangyo University, Kyoto, Japan
[4] Solar-Terrestrial Environ. Lab., Nagoya University, Aichi, Japan
[5] Inst. Space and Astronautical Sci., Kanagawa, Japan
[6] Department of Physics and Astronomy, University of Iowa, 203 Van Allen Hall, Iowa City, IA 52242-1479, United States
[7] Radio Atmospheric Science Center, Kyoto University, Uji, Kyoto 611-0011, Japan
[8] Solar-Terrestrial Environ. Lab., Nagoya University, 3-13 Honohara, Toyokawa, Aichi 442-8507, Japan
[9] Institute for Computer Science, Kyoto Sangyo University, Kyoto 603-8555, Japan
[10] Inst. Space and Astronautical Sci., 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan