Numerically rigorous techniques for the computation of electromagnetic fields diffracted by an object become computationally intensive, if not impractical to handle, at high frequencies and one must resort to asymptotic methods to solve the scattering problem at short wavelengths. The asymptotic methods provide closed form expansions for the diffracted fields and are also useful for eliciting physical interpretations of the various diffraction phenomena. One of the principal objectives of this book is to discuss the different asymptotic methods in a unified manner. Although the book contains explicit formulas for computing the field diffracted by conducting or dielectric-coated objects, it also provides the mathematical foundations of the different methods and explains how they are interrelated.

Le calcul numerique du champ diffracte par un objet est limite, aux courtes longueurs d'onde, par les capacites des ordinateurs. Les methodes asymptotiques haute frequence, inventees pour traiter ces situations, donnent des expressions entierement explicites du champ diffracte, ainsi qu'une interpretation physique des mecanismes de diffraction. L'ouvrage presente de maniere unifiee les differentes methodes asymptotiques. Il donne d'une part les formules essentielles permettant le calcul effectif du champ diffracte, en un point quelconque de l'espace, par un objet complexe conducteur, recouvert de materiau dielectrique. Il explicite d'autre part les fondements mathematiques des methodes presentees. Il permet donc d'acquerir une connaissance pratique ainsi qu'une comprehension theorique de ces methodes."