利用几何光学射线跟踪法对飞行器整体目标雷达散射截面(Radar cross section,RCS)进行估算,假设入射波为高频平面波,传播中符合几何光学定律,将入射波划分为平行入射线进行跟踪并进行口径积分。为减少射线与大型目标表面的求交计算次数,应用了KD树方法的基本原理,将飞行器目标表面划分多层子包围盒,设计了射线与子包围盒及面元遍历求交算法。应用文中方法计算了一种新型无人飞行器的RCS,计算结果与传统的RCS高频估算方法(PO方法)得到的结果以及实测结果进行比对。结果表明,文中方法较传统PO方法更接近实测结果,在飞行器RCS预估方面具有一定的应用价值。

Shooting and bouncing ray method is used to estimate RCS of aircraft, it's supposed that the incident wave is high-frequency plane wave. The transmission accords with the law of geometrical optics. We divide the incident wave into parallel rays and trace each ray, and then integrate the rays that send out of the integral surface. To reduce the calculation times of intersections of the rays and the faces of the huge aid,the fundamental KD tree method is used to divide surface of the aircraft into child bounding box. A method of traversal and intersecting judgment between the rays and the child bounding box or the surfels is designed. According to this method, the RCS of an aircraft is calculated in this paper. The calculated results are compared with the results calculated by the PO method and the measured results. It is shown that the results predicted by the method introduced in this paper are closer to the measured results than that by the traditional PO method. The solution in this paper has application value for predicting the RCS of unmanned aircraft.