Bidirectional reflectance measurements for satellite calibration target in the visible and near infrared

For the purpose of calibrating instruments carried on meteorological satellites, a stable diffusing surface is required to direct the sun's rays into the optical path. The bidirectional reflectance properties of six materials have been studied with a goniophotometer. It was found that pressed magnesium oxide exhibits the best diffusing properties, especially at a viewing angle of 40 degrees ; it was tested further and found to possess the necessary mechanical properties to survive launching conditions.