Location Accuracy Evaluation of ToA-Based Lightning Location Systems over Mountainous Terrain

In this paper, we analyze the location error of Time of Arrival (ToA)-based lightning location systems (LLSs) resulting from propagation over mountainous terrain. For the analysis, we have considered the region around the Säntis Tower, located in the Swiss Alps. The study is based on a full-wave finite-difference time-domain (FDTD) approach and the two-dimensional (2D) topographic maps along the direct path between the Säntis Tower and nearby sensor sites. The accuracy of the ToA lightning location results associated with times of arrival determined 1) as the time intercepts of straight lines passing through the peak of the return stroke pulse and different amplitude threshold crossing points, 2) as the time of the peak of the first derivative of the field and 3) as the time of occurrence of the peak value of the field are evaluated by using our full-wave FDTD method. The evaluated location errors associated with amplitude threshold crossing points of 10% and 20% of the initial rising amplitude of the field were found to be the lowest. Keywords—Lightning; Time of Arrival; FDTD; Säntis Tower; EUCLID