Abstract：In order to optimize the inversion algorithm of lightning location accuracy and discharge parameters, the paper introduces the conformal mesh technique to study the influence of real terrain of Fangchenggang on the lightning electromagnetic field propagation by using the 2 dimensional finite-difference time-domain. For comparing the lightning electromagnetic field propagation of the real terrain with the ideal flat ground, four hypothetical lightning strike points with different orientations are selected for simulation calculation, and the propagation distance from the lightning strike points to the observation point are all about 50km. The results shows that: ① For the vertical electric field, the real topography decreases the field values obviously to be from 5.1% to 54.8% , and the delay time caused by the real topography ranges from 1.5μs to 2.3μs; ② For horizontal magnetic fields, the influence of real topography is very little and only be from 4.8% to 16%, and the delay time for the real topography ranges from 1.2μs to 3.6μs. In addition, the comparative analysis found that due to the influence of real undulating terrain, there are different degrees of lag in the propagation time of lightning signals by the different definitions lightning signals arrival time, and the 10% threshold method has the lowest lag time as a whole.
2020, Vol. 21 
