Evaluation of Implementation of External Lightning Protection System: Case Study on the Military Radar Tower

A military radar unit is an operating unit that has the duty and responsibility to maintain the sovereignty of national airspace throughout the year. Considering that the installation area of military radar installations is in the mountainous, coastal, and marine areas, of course, this makes its own vulnerability to radar systems and their supporting electronic equipment from the threat of lightning strikes. The purpose of this study was to analyze the external protection system on radar towers based on the placement of installed air terminations. The analysis was carried out by applying the protection angle, rolling sphere, and collection volume method. From the results of research using the protection angle, it is found that using 1 air termination, increasing the air termination height to 38 m from the ground surface can protect all tower buildings and radar antenna from direct lightning strikes. The application of the rolling sphere on 4 air terminations on the radar tower is able to protect all tower buildings and radar antenna with a protection radius of each air termination as far as 45 m. By increasing the antenna height to 38 m from the ground surface, an analysis of the external lightning protection system using collection volume can protect all tower buildings and radar antenna from direct lightning strikes.