Time domain version of the UAPO solution for the field diffracted by an anisotropic impedance half-plane

This work deals with the time domain version of the Uniform Asymptotic Physical Optics solution for the field diffracted by the edge of a nonpenetrable half-plane characterized by an anisotropic impedance boundary condition. A transient plane wave is assumed obliquely incident on the scatterer in the more general case of principal axes of anisotropy not coincident with the edge. The time domain solution is obtained from the knowledge of the corresponding frequency domain expression in the hypothesis that the impedance tensor components along the principal axes of anisotropy do not depend on the frequency. An inverse Laplace’s transform is used to this end. The response to an incident unit step function plane wave is explicitly considered.