This book, written for applied scientists and engineers, is about efficient methods for calculating wave fields in a known inhomogeneous medium. It provides a link between the fundamental scattering theory and its discrete counterpart. Part I of this book discusses the forward scattering problem based on the contrast-source integral equations (Chapters 1, 2 and 3). In this case, the material properties are known and the book fully describes the calculation of the wave fields inside and outside a scattering object with general shape and material property. Part II discusses the inverse scattering problem (Chapters 4, 5 and 6). It is the problem of determining the material properties of a scattering object based on measured data. In fact, these measurements report how this object scatters the incident wave field. The theoretical approach is the inverse of the forward scattering problem that determines how radiation is scattered, based on the characteristics of the scattering object.
