Abstract: To study electromagnetic scattering by vehicle above ground,a half-space multilevel fast multipole algorithm (MLFMA) is proposed.Near terms in the MLFMA are evaluated by rigorous half-space dyadic Green functions.Far MLFMA interactions employ an approximate dyadic Green function via a direct-radiation term plus a single real image.The real image method leads to fast and convenient computation compared with the discrete complex image method (DCIM).It also results in less memory requirement and CPU time.Finally,bistatic radar cross sections are shown for a realistic 3D car model over lossy ground.

Key words: electromagnetic scattering, half-space Green's function, multilevel fast multipole algorithm, real image