ABSTRACT
For lightning protection purposes, it is essential to estimate the probability that lightning strikes different parts of a structure because most damage is normally caused close to the striking point. A method used for engineering applications is based on the concept of the attractive distance—the lightning sphere model, which was originally launched by Gilman and Whitehead as the electrogeometrical model, where the lightning protection criteria are related to the peak lightning current and the striking distance. The chapter proposes improved models of lightning return stroke and of lightning interception. It suggests mechanisms which may influence the frequency of lightning strikes to different parts of the air termination of a lightning protection system and which could be included in an improved model of lightning interception. A number of observations of natural lightning and long laboratory sparks have shown that in the enforced field of the downcoming leader streamers start from several points of structures aboveor even from the ground itself.
