Point source diffraction by a strongly elongated spheroid

Recently a high-frequency asymptotic approach was developed for the analysis of the problems of diffraction by strongly elongated ideal spheroids. In this paper we extend this approach to deal with the fields of point sources and also derive asymptotic expressions at finite distances from the spheroid in the forward direction. The main assumption which leads to the uniform, with respect to the rate of elongation, representation can be formulated as the proportionality of the length of the body to the square of its perpendicular cross-section, measured in wavelengths. The leading order approximations are presented in the form of rapidly converging integrals, which contain the Whittaker functions.