Study on the Electromagnetic Scattering Characteristics of High-Speed Target With Non-Uniform Plasma via the FCC-FDTD Method

The face-centered cube (FCC) grid has more sampling points than the traditional Yee cell (as it contains a total of 14 grid points, of which six are center points and eight are vertices, and each grid point has three field components). Thus, FCC is better than the former in dealing with the dispersion error of anisotropic media. On the basis of this feature, this article first derived the FCC-finite-difference time-domain (FDTD) iterative formula for nonuniform plasma on the basis of FCC grid and verifies the accuracy of the algorithm. This algorithm is combined with the nonuniform plasma flow field model of hypersonic vehicles, and the backward single-station radar cross sections (RCSs) of vertical polarization (VV) and horizontal polarization (HH) are calculated under different flight altitudes, flight velocities, and external conditions. Results showed that as flying height increased or flying speed decreased, it results in an increase in RCS. Different external magnetic fields and incident angles also had an obvious impact on the electromagnetic scattering characteristics. From the perspective of electromagnetic wave polarization, both VV polarization and HH polarization have a great impact on RCS. These results provide a theoretical basis for studying the electromagnetic scattering characteristics of nonuniform plasma targets.