Gray Spectralon polarized reflectance deviations from Lambertian

Abstract

While Spectralon panels are largely assumed to be ideal Lambertian surfaces, their actual polarized reflective responses deviate from the ideal by at least a small amount at illumination and viewing angles off surface normal. The Mueller matrix response of four different panels between 10% and 99% reflectance were measured and the radiometric response from two distinct monostatic or nearmonostatic polarimeter systems are compared, one at Montana State University and one at the Air Force Research Lab. The deviations from an assumed ideal Lambertian surface are reported.