Airborne Aerial Radars are often required to track a large number of ground vehicles moving within a specific area. When simulating such a radar, detection computation must consider the existence of line of sight between the radar and each of the simulated ground platforms, resulting in multiple long range LOS computations performed simultaneously, from a single aerial point. When using very high resolution terrain with ground vehicles scattered over large areas (hundreds of square miles) in dense vegetation, urban structures and mountainous terrain, the polygon count required for geometry intersection calculations used by each LOS query can be very high. In some cases, processing multiple LOS queries, results in poor simulation performance. This paper suggests a simple approach for reducing the number of required LOS calculations, where multiple long-range LOS queries originate from the same aerial point. By using a shadow map generation method and positioning the source of light at the LOS origin point, Ground points that are inside a shadow can then be filtered out from further LOS computations. The more ground points there are the better cost effective this method is.