说明：  该程序用fortran90编写，时域有限差分（FDTD)中的近远场变换方法。解决了电磁波后向散射中的RCS计算
(FORTRAN90 prepared with the program, finite difference time domain (FDTD) in the near field to far field transformation method. Resolved backscattering of electromagnetic waves in the RCS calculation)