Analysis And Research On Lightning Radiation Electromagnetic Fields Based On FDTD Method

In order to investigate effects of the ground resistivity to lightning radiation electromagnetic fields produced by lightning return-stroke, a three-dimensional finite-difference time-domain (FDTD) numerical model near the lightning channel is developed with the lightning current's transmission line model. Lightning radiation electromagnetic fields at varied ground structures are analyzed and effects of different soil resistivities to lightning radiation electromagnetic fields are compared. The computed results indicate that the resistivity of the monolayer ground has greater effects on the lightning radiation electric field than the magnetic field; effects made by the horizontal stratified ground lie mainly on the resistivity of the top ground and effects made by the vertical stratified ground are slightly. In the end, the regularity of amplitude and rise time for different soil resistivities is shown.