ABSTRACT
The development of powerful digital recorders with enough bandwidth to capture the microstructure of lightning waveforms and the advent of digital computers and fiber optic communication along with sophisticated direction finding sensors facilitated the extraordinary evolution of lightning monitoring and detection techniques. Ground flash density (GFD), frequently referred to as GFD or Ng, is defined as the number of lightning flashes striking ground per unit area and per year. Lightning parameters are sometimes standardized for the purpose of the assessment of lightning performance of specific power line designs. Parameters that is important for the assessment of lightning performance of power transmission and distribution lines or for evaluation of different protection methods are lightning current and GFD. Power lines, for example, are prone to failures even if GFD levels are low when they pass through high-resistivity soils like deserts or when lines span across hills or mountains, where ground wire or lightning arrester earthing becomes difficult.
