Measurements and parameterization of the bidirectional reflectance factor of BaSO4 paint

E. R. Young, Regis College
K. C. Clark, University of Washington
Robert B. Bennett, Central Washington University
T. L. Houk, University of Maryland Hospital

This article was originally published in Applied Optics. The full-text article from the publisher can be found here.

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Abstract

Comprehensive measurements of the bidirectional reflectance factor of BaSO₄ 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 BaSO₄ deposit gives the most reproducible diffuse reflectivity. It is also shown that a spray deposit of BaSO₄ 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.