On scattering by large conducting bodies

Two sets of sources, equivalent in the sense that they produce the same field as does an illuminated conductor, are discussed. Both representations are suggestive of approximation. Crude approximations are made, yielding what are called "the physical optics solution," and the "image induction solution." It is shown that these two solutions are reciprocal to each other. This means that, given a source and an observer, the solution by one method is equal to the solution by the other method with the source and observe interchanged. Both solutions are amenable to further refinement if more accurate solutions are desired.