Simultaneous observations of lightning radiations from above and below clouds

Daytime optical measurements of a lightning flash made simultaneously from above and below a thundercloud show nearly identical signals. The optical pulses are clearly related to electric field changes detected by an E change meter and to the signals detected by a 2200 MHz receiver. Source power levels ranging from 10 7 to 10 10 W optical were detected at 20 km altitude from three lightning flashes.