Radar scattering from blunted cone tips

The radar cross section is calculated for semi-infinite perfectly conducting cones with tips which are blunted in one of several ways. Calculations have been performed for nose-on incidence using exact theory, and for nose-on and near nose-on incidence using the physical optics approximation. The calculations have been restricted to narrow-angle cones and, in most cases, to tip dimensions small compared with a wavelength. For the rounded tip (spherical tip attached smoothly to the cone), the calculations agree very well with the physical optics approximation. Thus, the use of physical optics for nonzero aspect angles seems justified.