Lightning Rod - Analysis of Strikes

Analysis of Strikes

Lightning strikes to a metallic structure can vary from leaving no evidence, except perhaps, a small pit in the metal, to the complete destruction of the structure (Rakov, Page 364). When there is no evidence, analyzing the strikes is difficult. This means that a strike on an uninstrumented structure must be visually confirmed, and the random behavior of lightning renders such observations difficult. There are also inventors working on this problem, such as through a lightning rocket. While controlled experiments may be off in the future, very good data is being obtained through techniques which use radio receivers that watch for the characteristic electrical 'signature' of lightning strikes using fixed directional antennas. Through accurate timing and triangulation techniques, lightning strikes can be located with great precision, so strikes on specific objects often can be confirmed with confidence.

The energy in a lightning strike is typically in the range of 1 to 10 billion joules. This energy is released usually in a small number of separate strokes, each with duration of a few tens of microseconds (typically 30 to 50 microseconds), over a period of about one fifth of a second. The great majority of the energy is dissipated as heat, light and sound in the atmosphere.