Improved theory of acoustic elementary edge waves

Abstract

The high-frequency asymptotic theory of acoustic edge waves [P. Ya. Ufimtsev, J. Acoust. Soc. Am. 86, 463–74 (1989)] is well suited for investigation of backscattering from perfectly reflecting (soft or hard) three-dimensional objects with edges. However, it needs to be improved for calculation of forward scattering, especially in the directions grazing to the edge faces, where it predicts infinite values. The present paper removes this singularity by the appropriate choice of the so-called uniform component of the surface field. It is defined here as the field induced on the half-plane tangential to the illuminated face of the scattering edge (and to the edge itself). An improved theory of elementary edge waves is proposed, which is valid for all directions of scattering, including the forward grazing directions.