0°:45°a Radiance Factor Measured by a BRDF System

摘要

Radiance factor under the 0°:45°a geometric condition can be simply obtained by a commercial spectrophotometer using substitution method. This is acceptable only if the measured surface and/or the responsivity of the optical detecting system is uniform. This article intends to show that it is necessary to measure the bidirectional reflectance distribution function (BRDF) in order to obtain the 0°:45°a radiance factor accurately, especially for non-uniform surfaces and optical detecting system.