Light scattering in the physical optics approximation; application to large spheroids

Abstract

The field radiated everywhere in space may be expressed by means of an integral, in terms of the surface field over a closed surface S. S being the surface of a regular shaped scatterer, that unknown surface field has been evaluated by using the Physical Optics Approximation. The method requires the use of Fresnel's and Snell's laws for plane waves which may be inhomogeneous since the scatterer may have a complex refractive index. Accounting for the finite curvature of the scatterer, the amplitude and phase of the waves inside the scatterer have been calculated. A program which allows the computation of the usual four components of the scattered light has been implemented, checked in various particular situations and been successfully used in the case of a spheroidal scatterer at nose-on incidence.