HR: 1330h
AN: AE22A-1116    [PDF]
TI: Operational VHF Broadband Digital Interferometry and Observation of Thunderstorm
AU: Matsumoto, A
EM: Matsumoto.Akinori@chuden.co.jp
AF: CHUBU Electric Power Co., Inc., 20-1 Kita-sekiyama Oodaka-cho Midori-ku, Nagoya, 459-8522 Japan
AU: Shimizu, M
EM: Shimizu.Masahito@chuden.co.jp
AF: CHUBU Electric Power Co., Inc., 20-1 Kita-sekiyama Oodaka-cho Midori-ku, Nagoya, 459-8522 Japan
AU: Morimoto, T
EM: morimoto@comf5.comm.eng.osaka-u.ac.jp
AF: Department of Communications Engineering Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, 565-0871 Japan
AU: Sonoda, Y
EM: sonoda@comf5.comm.eng.osaka-u.ac.jp
AF: Department of Communications Engineering Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, 565-0871 Japan
AU: * Kawasaki, Z
EM: zen@comf5.comm.eng.osaka-u.ac.jp
AF: Department of Communications Engineering Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, 565-0871 Japan
AU: USHIO, T
EM: ushio@aero.osakafu-u.ac.jp
AF: Department of Aerospace Engineering Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, 599-7531 Japan
AB: Chubu Electric Power Corporation (CEPCO) and Lightning Research Group of Osaka University (LGOU) have been conducting a cooperative project of thunderstorm observations during a couple of summer seasons. The main objective of the project is to realize an operational VHF broadband interferometer as a lightning monitoring system. The VHF broadband interferometer has been proposed by the group of New Mexico Tech and LRGOU independently and simultaneously. LRGOU has been working for developing the system, and accomplished the experimental system of the VHF broadband interferometers. Following this, CEPCO and LRGOU has designed a special A/D converter and broadband VHF antenna for interferometry. The A/D converter owns three channels, and can capture at most 2048 VHF pulses for one lightning flash with 200MHz sampling frequency. The time window for one VHF pulse is 2.5 microseconds, and it is sufficient to record VHF pulses radiated from lightning. They carried out field campaigns during summer thunderstorm seasons, and captured a lot of data. The location of 3D VHF radiation sources has been accomplished. Basically one VHF pulse in one time window gives us the continuous development image of lightning discharge. Two or three VHF pulses are eventually noticed in a 2.5 microseconds-window. Though we speculate it may be the evidence of _gthe bi-directional leader concept_h, the interpretation in terms of the data analysis is not completed yet. They intend to compare VHF broadband interferometer observations with a Doppler radar data to confirm the performance of the system. They conclude tentatively that the function of the system is working well, and the VHF broadband interferometer for lightning monitoring is accomplished with high accuracy from the aspects of time and space.
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
DE: 3360 Remote sensing
DE: 3394 Instruments and techniques
SC: Atmospheric and Space Electricity [AE]
MN: 2003 Fall Meeting