%0 Journal Article
%A
%T High-frequency scattering in a certain stratified medium: the three-part problem
%D 1977
%R 10.1098/rspa.1977.0136
%J Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences
%P 315-343
%V 356
%N 1686
%X The high-frequency scattering of scalar waves by a plane boundary in a certain two-dimensional stratified medium is considered. On the boundary, it is assumed that the impedance takes three different values. A high-frequency approximation to the solution is found for certain positions of source and point of observation; it is proved rigorously that the approximation is asymptotic to the exact field in the limit of high frequency. Physically, the results imply that energy propagates by means of Kellerâ€™s creeping modes, mode conversion occurring at the points of impedance discontinuity.
%U http://rspa.royalsocietypublishing.org/content/royprsa/356/1686/315.full.pdf