Abstract : The characteristics of lightning, artificially induced by wire-trailing rockets were measured in a cooperative program involving investigators from France, from the Flight Hazards Branch of Wright-Patterson Air Force Base and from New Mexico Institute of Mining & Technology. Lightning currents ranging from a few hundred amperes to a peak of 79 kA were measured. The waveforms of the electromagnetic signals produced by the lightning had associated magnetic field variations in excess of 10 T/s with rise times ranging from 40 ns to 1 microsecond. The development of an 11 cm radar was completed for a determination of the interaction between lightning and the surrounding atmosphere. Preliminary data on lightning echoes have now been obtained with it.