On the asymptotic diffraction of scalar waves by a wedge

The diffraction of plane, cylindrical and spherical waves by a wedge is considered. Particular emphasis is placed on finding accurate and simple asymptotic field expansions which are valid in the transition regions as well as in the far field. The accuracy of previous diffraction coefficients for cylindrical and spherical waves is discussed and a more accurate derivation is presented. A new simple rational approximation of the resulting Fresnel integral is given and its special character is demonstrated.