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PRECISE MEASUREMENT OF POLARIZATION
PLANE ROTATION OF PROPAGATING BEAM
DUE TO ATMOSPHERIC DISCHARGE
TATSUO SHIINA and TOSHIO HONDA
Graduate School of Advanced Integration Science, Chiba University,
1-33 Yayoi-cho, Inage-ku, Chiba-shi, Chiba 263-8522, Japan
TETSUO FUKUCHI
Central Research Institute of Electric Power Industry,
2-6-1 Nagasaka, Yokosuka-shi, Kanagawa 240-0196, Japan
The rotation of polarization plane of a propagating beam caused by a high
voltage discharge was experimentally examined. Using a CW visible laser and
repeating mirror optics, the rotation angle of < 1 deg was measured with a
differential detection of > 30 dB. The waveform of the rotation angle showed
good correlation with the discharge current waveform, with a correlation
coecient of
>
0.94.
1. Introduction
Meteorological observation technology has suciently developed to enable
accurate weather prediction, while local disasters such as heavy rain and
lightning stroke have not decreased. In Japan, flood and lightning cause
over 10 and 100 deaths per year, respectively. Automated Meteorological
Data Acquisition System (AMeDAS), which is operated by the Japan
Meteorological Agency, uses a cell size of 20 km square area. Observations
using meteorological satellites use a cell size of 4 km square area. Therefore,
it is di cult to detect rapid local weather change, which accompany heavy
rain and lightning strikes.
Electromagnetic antennas are mainly used to detect lightning strikes.
Lightning detection and positioning systems such as SAFIAR and LPATS are
in operation in Japan. The antenna measurement requires numerous obser-
vation points synchronized in time to obtain the lightning strike position,
and lacks flexibility of measurement. Radar has the flexibility of single-point
measurement, while its use is limited because of legal restrictions on the use
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