Probability of lightning strikes to air-terminations of structures using the electro-geometrical model theory and the statistics of lightning current parameters

In planning air-terminations for a structure to be protected the use of the rolling-sphere method (electro-geometrical model) is the best way from the physics of lightning point-of-view. Therefore, international standards prefer this method. However, using the rolling-sphere method only results in possible point-of-strikes on a structure without giving information about the probability of strikes at the individual points compared to others. Extending the electro-geometrical model using the probability distributions of natural lightning parameters, and implementing this idea into a numerical simulation computer code give the possibility to show the different exposure of individual points of a structure to direct lightning strikes and with that the different “efficiency” of air-terminations at these points. The results of the method described may help in the future, to optimize the planning of air-terminations due to their lightning strike capturing efficiency.