A method for the asymptotic solution of diffraction problems

The equation for the propagation of harmonic waves in a homogeneous medium is considered as the transform of an hyperbolic equation in one more variable. The boundary value problem of diffraction theory cans by this Laplace transform, be related to Cauchy´s problem. The transformed problems are solved for 2 + 1 variables by methods introduced by Evvard and Ward in supersonic airfoil theory. As an example the diffraction problem for a strip is worked out and an asymptotic expression for the transmission cross section is given.