Curved surface scattering geometry in the shooting and bouncing rays method

Although many practical cases may suggest otherwise, in general, the curved-surface DF correction should not be ignored in SBR. In some cases, the results can be disastrous, especially for problems involving multi-reflector antennas or single-reflector antennas interacting with an installation platform or radome. For this reason, using flat-surface CAD models is problematic for multi-bounce SBR unless the patches are supplemented with curvature data. A more practical solution is to use curved surface models, such as NURBSs, where local curvature information is built into the CAD primitives.