抄録
For obtaining three-dimensional properties of streamer discharges we propose a new stereographical method in which streamers are observed simultaneously from three angles of 0°, 90°, and 225°. Two photographs taken from 0° and 90° individually provide the horizontal and depth coordinates of each streamer channel, as well as the vertical coordinate obtained from the both photographs, while the other taken from 225° yields clues for specifying identical streamer channels from the former two photographs. This method enables to maintain the absolute error of the depth coordinate low, differently from typical stereogram. Using the observation method we have demonstrated the evaluation of the propagating velocity and several branching characteristics of streamer channels.
