DOUBLE REFLECTIONS IN THE PHYSICAL THEORY OF DIFFRACTION.

The radar cross section (RCS) of a dihedral corner reflector is analyzed using the physical theory of diffraction in the azimuthal plane for 90 degree , 98 degree and 77 degree interior angles. This is compared to an analysis using geometrical optics with physical optics. It is concluded that geometrical optics for initial reflections in physical optics analyses simplifies the preparation of computer algorithms for predicting RCS patterns from objects formed of perfectly conducting flat plates. No numerical integrations are necessary and no potentials need to be found. In contrast, the strict application of physical optics for all reflections makes the analysis formulation complex, but improves accuracy.