Scalar Diffraction by a Prolate Spheroid at Low Frequencies

For the scalar problem of the diffraction of a plane wave by a prolate spheroid the exact solution is known, and by expanding this in ascending powers of ka, where k is the wave number and 2a is the interfocal distance, the Rayleigh series for both the "soft" and "hard" bodies are obtained up to and including terms in (ka) 6 . The corresponding results for an oblate spheroid can be deduced by a trivial change of parameters. Some particular cases are examined.