Influence of Surface Roughness on The Specular Reflectance of Low Gloss Coatings Using Bidirectional Reflectance Measurements

摘要

The objective of this study was to determine the effects of surface roughness and incident angle on the reflectance of low gloss coatings at grazing incidence. A specular peak has been identified from the forward scatter at longer wavelengths, 3.39 &(number sign)956;m and 10.6 &(number sign)956;m, for various painted surfaces. Depending on the surface roughness and wavelength, this specular component occurs at different angles. However, this effect has not been observed in the visible region. Material surfaces with well characterized surface roughness have been measured at a wavelength of 0.633 &(number sign)956;m in an attempt to observe this effect in the visible region. The angle at which it was observed for various roughnesses has been obtained using bidirectional reflectance distribution function (BRDF) measurements.