ABSTRACT
A complete lightning discharge consists of many diverse transient processes that generate high-level electromagnetic signals in the vicinity of the flash over a typical period of 0.5 s. The earliest motivation for studying lightning properties arose in connection with the development of electrical power distribution systems when it was discovered that lightning strikes to power lines could destroy substantial parts of the system. As indicated earlier 10,000 or more VHF pulses occur during a lightning flash. Although lightning signal measurements were first carried out using frequency domain systems, atmospheric electricians recognized that much could be learned from time domain measurements, but they were hampered by the limited bandwidths of the available oscilloscopes. The lightning flash—whether intracloud—changes the distribution of charge in a thundercloud in a time representing an appreciable fraction of a second, and involves many types of subsidiary electrical sparks and discharges. The chapter presents the results of lightning electromagnetic measurements in perspective for the nonlightning specialist.
