BRDF Measurements At 6328 Angstroms And 10.6 Micrometers Of Optical Black Surfaces For Space Telescopes

Abstract

Bidirectional Reflectance Distribution Function (BRDF) measurements that characterize the optical scattering properties of surfaces are extremely important to the design of space telescopes and instruments. Sophisticated stray light analysis codes such as APART/PADE require a characterization of the scattering function of optical black surfaces at several angles of incidence and a wide range of detector angles. This paper presents BRDF measurements taken at 5 and 30 degrees incidence of both space qualified black surfaces and some new black surfaces designed for future space instrument and telescope use. These surfaces represent the optical black surfaces most commonly specified for space telescope and instrument baffle and vane surfaces. The scatter measurements were made on a newly built visible and infrared scatterometer designed for accurate measurements of the scatter function of black surfaces.