适用于裁剪NURBS曲面RCS预估的改进的物理光学法

Improved PO technique for the RCS computation of targets modeled with trimmed NURBS surfaces

分析了驻相法(SPM)计算裁剪非均匀有理B样条(NURBS)曲面上物理光学积分失效的原因;在此基础上综合驻相法和Gordon算法的优点,提出了SPM-Gordon算法来准确快速计算裁剪NURBS曲面上的物理光学积分.与完全采用高斯积分计算裁剪曲面上物理光学积分的传统方法相比,新算法避免了繁琐耗时的数值积分,计算速度快,所需内存少.数值结果表明,当裁剪曲面被裁去区域与有效域面积之比小于0.5时,在同等精度下,对于采用裁剪曲面建模的大多数目标,SPM-Gordon算法计算RCS所需的时间仅仅为传统方法的10%以下.

The invalidity of the stationary phase method（SPM） in the evaluation of the PO integral over trimmed surfaces is analyzed theoretically,on the basis of which the SPM-Gordon algorithm is presented to evaluate the PO integral over trimmed surfaces accurately and effectively.Compared with the conventional method in which numerical integrations are utilized,this new algorithm successfully avoids the complex and time-consuming numerical integrations and releases the heavy burden on the CPU.Numerical results indicate that when the area of the trim region is less than half of that of the effective region,the time consumed by the SPM-Gordon method is no more than 10 percent that by the conventional method in most cases.