插值逼近结合FDTD法快速计算目标宽角度RCS

FDTD(Finite Difference Time Domain)法结合多项式插值逼近和样条函数插值逼近快速计算了三维目标的宽角度RCS(Radar Cross Section).引入插值逼近方法可以节省计算时间.在整个入射角度范围内选定若干个入射角,对不同的入射角,分别用FDTD法计算得到外推面上各点的切向电磁场值,进而得到这些场值随入射角度变化的插值函数,然后用插值函数计算出全入射角度范围内外推面上各点的切向电磁场值,最后通过近远场变换得到宽角度RCS.计算结果表明,在只有少数几个插值节点的情况下该方法就能很好地逼近FDTD法的精确计算结果,节省了计算时间.

Fast calculation of wide angle RCS pattern of objects based on interpolation technique and FDTD method

Fast calculation of wide angle radar cross section(RCS) pattern of 3-D objects based on multinomial interpolation approximation and spline approximation was presented.When interpolation technique was introduced in finite difference time domain(FDTD) method,the calculation time was reduced.Firstly,several angles of incidence were chose in whole range of angle,and FDTD calculation were employed with those angles one by one,and the tangent electric and magnetic values on extrapolation boundary were obtained.Then,the approximating functions related to angle of incidence were gained.Secondly,the tangent electric and magnetic values on extrapolation boundary were calculated by approximating function in whole range of incident angle.Finally,wide angle RCS pattern of 3-D object were calculated by a near-to-far field transformation.The numerical results are in good agreement with the results achieved by the method of FDTD at any incident angle,even if several interpolation node is used,and the computational time is reduced.