Monitoring of lightning activity based on simultaneous measurement of electric field and electric field-change in the Tokyo metropolitan area

Kozo Yamashita, Ashikaga University, Dept. of Innovative Engineering, Ashikaga, Japan, Hiroyo Ohya, Chiba University, Chiba, Japan, Yukihiro Takahashi, Hokkaido University, Sapporo, Japan and Mitsuteru Sato, Hokkaido University, Faculty of Science, Sapporo, Japan