1. Department of Physics; Umeå University; PO Box 812; 981 28; Kiruna; Sweden
2. Nippon Meteor Society; 2-16-8 Mikunihonmachi; Yodogawa-ku; 532-0005; Osaka; Japan
3. Department of Information and Communication Systems; Tokyo Metropolitan University; 6-6 Asahigaoka, Hino; 191-0065; Tokyo; Japan
4. Swedish Institute of Space Physics (IRF); PO Box 812; 981 28; Kiruna; Sweden
5. National Institute of Polar Research (NIPR); 10-3 Midoricho, Tachikawa; 190-8518; Tokyo; Japan