Abstract
Lightning occurrence frequency is an important factor for lightning protection design. The IKL map has been used to estimate the lightning occurrence frequency, but recent progress of lightning location systems such as the LLP system and LPATS shows a possibility to make a more accurate map than that used now. In order to make such a map, present status of lightning location systems in Japan is surveyed and detection efficiency of the systems is clarified. A method to make the lightning frequency map with these data is proposed and an example of the map is shown.
