When calculating the electromagnetic scattering characteristics of curved targets using 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.

In the modified method, 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 divergence 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.

The numerical 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.

The DF correction is important for improving the accuracy of the SBR method in calculating the scattering characteristics of curved targets.