Abstract

Polarization correction to high-frequency single-scattered fields from smoothly curved surfaces has been obtained in the past through evaluation of the next-to-leading term in the Luneburg–Kline (L–K) expansion of the scattered fields. For a backscattering situation, the correction term has been found to depend on the difference between the principal curvatures of the surface at the specular-reflection point. The above is classified as a geometrical-optics approach. For scattering surfaces that are locally cylindrically symmetric at the specular point, one would have to dig deeper into the L–K series to find the cross-polarization term—a formidable task. In such cases it pays to resort to an approach based on physical optics. The classical physical-optics solution is recognized as the leading term in the Neumann-series representation of the solution to the magnetic-field integral equation. This solution is known to be copolarized with the incident field. We derive the next term in this representation, evaluate it in the high-frequency limit, and separate the cross-polarization term from the result.

© 1990 Optical Society of America