Fast calculation of wide angle RCS pattern of 3-D object based on hermite interpolation technique and FDTD method

The wide angle radar cross section (RCS) pattern of 3D object can be quickly calculated by the Hermite interpolation approximation based finite-difference time-domain (FDTD) method. Generally, when calculating the wide angle RCS pattern of 3D object, FDTD calculation is needed to be performed once whenever the incident angle changes. Introducing the Hermite interpolation technique in FDTD method can save the calculation time. Firstly, several incident angles are chosen in whole range of angle, and FDTD method is employed with those angles one by one, and the tangent electric and magnetic values including differential values on extrapolation boundary are obtained. Then, the approximating functions related to incident angle are obtained. Secondly, the tangent electric and magnetic values on extrapolating boundary are calculated by approximating function in whole range of incident angle. Finally, wide angle RCS pattern of 3D object is calculated by a near-to-far field transformation. The numerical results are in good agreement with the results achieved by FDTD method at any incident angle, and the computational time is reduced.