Directorate of Planning and Technology Electronic Systems Division Air Force Systems

It is shown how, by carrying out a sequence of three coordinate axis rotations in Poincare space, one can calculate the principal basis and the real, nonnegative eigenvalues of any symmetric polarization scattering matrix. Then the two eigenvalues and the three Eulerian angles of the principal axes in Poincare space constitute a complete set of pure scatterer parameters. A scatterer classification scheme based on these parameters is constructed, with the help of a geometrical representation, in Poincare space, of polarization transformations. The procedure is applied to several simple scattering configurations. Some conclusions are reached concerning the scatterer geometry in various cases.