Application of the generalised radiance function for prediction of the mean RCS of bent chaotic ducts with apertures not normal to the duct axis

A method is proposed to approximate the mean radar cross-section (RCS) of a chaotic electrically large bent duct with an aperture not necessarily normal to the duct axis. This is based on a ray mapping of the generalised radiance function (GRF) associated with a random field. The field within the duct is assumed to be represented by a scalar function and a homogenous Schell model is assumed to describe the backscattered transverse field at some cross-section within the duct. The GRF associated with this field may then be mapped to a general aperture where the mean RCS can be determined. An analytic example is provided where a chaotic bent duct is terminated by a prism-shaped precursor structure