Relativistic FDTD Analysis of Far-Field Scattering of a High-Speed Moving Object

Far-field scatterings of uniformly moving conducting and dielectric objects are analyzed in this letter. Using the Lorentz transformation, the scattering problem of a high-speed moving object in the laboratory frame, which is stationary with respect to the free space, is transformed to that of a motionless object in the rest frame that moves with the moving object. Then the near-zone scattered fields are solved by the Finite Difference Time Domain (FDTD) algorithm. Applying near-to-far field transformation, far-zone scattered fields are acquired in the rest frame. Subsequently, the scattered fields are transformed back to the laboratory frame. Our approach is validated against previously published results for the case of a uniformly moving two-dimensional object. Numerical examples show that the effects of the motion on the bistatic radar cross sections (RCS) and Doppler are non-negligible for high-speed objects.