BRDF variability of typical diffuse reflectance standards between 380 nm and 1700 nm

Comparison of the reflectance properties of different diffuse reflectance standards provides guide to select the standard most adequate for a given application. IO-CSIC and PTB have studied the variation of the spectral BRDF with respect to the standard bidirectional geometry 0º:45º of the four most typical diffuse reflectance standards (barium sulphate, opal glass, ceramic tile and Spectralon), within the spectral range [380-1700] nm. IO-CSIC measured the variation in-plane spectral BRDF at several incidence angles, whereas PTB measured its out-ouf-plane variation at a fixed 45º incidence angle.