Ellipsometric parameters, depolarization and directional reflectance of reflection and scattering by a rough stainless steel surface are measured. Linear and circular polarizations, and principal Mueller matrix can be obtained from the above quantities. Measurements were made at fixed incident and detection directions and variable sample's orientation. For one-dimensional rough surfaces, it was found that depolarization and circular polarization increase with the off-specular angle of scattering while linear polarization does the opposite. Measurements were also made for specular direction. The effective refractive index, extinction coefficient and rms roughness for the rough sample were derived from these data.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.