Synchronized Multipoint Measurements of Lightning Electric Field Changes

Abstract

Exploiting GPS systems, we synchronized three wideband (0.1Hz-2MHz) slow antennas with the time accuracy of lμs. With this slow antenna system, we recorded many lightning flashes at Hokuriku district area from December 2, 1993 to January 28, 1994. Almost all lightning flashes show consecutive pulses superimposing on their slow field changes with the time intervals of tens microseconds. We analyzed the arrival time difference of the pulses to different stations and succeeded in locating the sources of the pulses which are from PB(Pleliminary Breakdown), L(Leader), R(Return stroke), and C(Continuing current) stage for a positive cloud to ground discharge, and from recoil streamers for a cloud discharge. Since we combine the functions of traditional slow antennas with lightning location method, this paper would provide a significant tool to study lightning physics, especially the physics of the initiation of lightning.