计算曲面结构目标的发散因子修正弹跳射线法

Modified shooting and bouncing ray method with divergence factor for calculating curved targets

[目的]在使用弹跳射线法(SBR)计算曲面目标的电磁散射特性时,若采用平面片离散曲面结构,会对射线管的波前计算以及射线跟踪造成较大误差,导致仿真结果的置信度明显下降,因此需进行算法修正。[方法]在修正算法中利用曲面拟合技术重塑三角型离散模型的曲率信息,基于微分几何计算射线管波前曲率,进而引入发散因子修正射线管的幅值。另外,对于采样精度下降的发散射线管,设计出新的射线追踪方法,并实现射线管对目标表面的超采样。[结果]数值结果表明,修正后的算法有效提高了射线管的采样精度和曲面结构目标的计算准确度。[结论]发散因子修正对于提高弹跳射线法计算曲面目标散射特性的准确度具有重要意义。

[Objective]When calculating the electromagnetic scattering characteristics of curved targets us-ing the shooting and bouncing ray(SBR)method,there is a large error in the calculation of the wavefront of the ray tube and ray tracing if the surface is discretized using a planar mesh,resulting in the low confidence level of the simulation results.As such,a modified algorithm is required.[Methods]In the modified meth-od,the surface fitting technique is used to reshape the curvature information of the triangular meshed model,then the wavefront curvature of the ray tube is calculated on the basis of differential geometry,and the diver-gence factor(DF)is introduced to correct the amplitude of the ray tube.In addition,a new ray-tracing method is designed for the divergent ray tubes to realize oversampling on the target surface.[Results]The numeric-al results show that the algorithm in this paper effectively improves the sampling accuracy of the ray tube and the accuracy of the simulation of the curved surface target.[Conclusion]The DF correction is important for improving the accuracy of the SBR method in calculating the scattering characteristics of curved targets.