Measurements and parameterization of the bidirectional reflectance factor of BaSO(4) paint

Comprehensive measurements of the bidirectional reflectance factor of BaSO(4) paint vs both viewing and illumination angles are presented as contour plots. Contours resulting from several surfacing techniques are compared to demonstrate that a machined surface on a thick BaSO(4) deposit gives the most reproducible diffuse reflectivity. It is also shown that a spray deposit of BaSO(4) gives a much less diffuse reflectivity. We also show that the contours of bidirectional reflectance of either machined BaSO4 or smoked MgO may be described by a three-parameter fit, which automatically obeys the Helmholtz reciprocity theorem and is simply related to the efficiency of total reflectance.