“…From the perspective of computational electromagnetism, the HPEMP effect on vehicles is a composite time-domain scattering problem. Numerous numerical approaches have been widely used, such as the Method of Moments (MoM) [6,7], the Finite-Difference Time-Domain (FDTD) method [8][9][10], the Finite Element Method (FEM) [11,12], the Time-Domain Integral Equation (TDIE) method [13,14], and other hybrid methods [15,16]. However, to calculate the coupling between the vehicle and the half-space, most existing algorithms need to use half-space Green's function, which is extremely difficult to derive and calculate, particularly for multi-layered planar medium and rough surfaces.…”