Numerical simulation of the exposed area of high-altitude electromagnetic pulse on the ground and its influencing factors

Abstract

Abstract In traditional High-Altitude Electromagnetic Pulse (HEMP) research, the line-of-sight area on the earth’s surface of the burst is approximately regarded as the exposed area of HEMP on the ground. However, the line-of-sight area is only affected by the height of burst, and cannot reflect the influence of yield and the distribution of peak HEMP fields on the ground. In this paper, the ground distance between ground zero and the southernmost point of peak HEMP field contour is defined as south radius for explosions in the northern hemisphere. The numerical simulation results of south radius of different peak HEMP field contours are given, and the impact of burst height and yield on south radius is analysed. It is concluded that when the yield is fixed, the south radius increases first and then decreases as the burst height increases. When the burst height is fixed, the south radius increases as the yield increases, but the rate of increase keeps decreasing.