The monograph is a sequential presentation of the discrete source method applied to the analysis of mathematical models of electromagnetic wave propagation processes in the presence of local lenses. Particular attention is paid to the development of the theoretical foundations of the method, which allows constructing numerical models, taking into account all the features of the boundary problems under consideration. In detail considered; computational schemes that implement a stable algorithm for determining the amplitudes of discrete sources. The results of numerical analysis on the computer of various mathematical models of scattering problems, including the study of mathematical models, biological objects.