Abstract
The combination of high emissivity requirements and volume constraints has led to the development of space-flight blackbody designs exhibiting anisotropic emission characteristics. While generally isotropic over some nominal range the behavior of these blackbodies at greater off-nominal angles is complex and small errors in design or fabrication could cause unwanted characteristics. The performance of these designs is assessed with optical models but the optical models themselves need to be validated with laboratory measurements. To perform this validation ATK-Military Systems and Ball Aerospace have developed a gonio-reflectometer to measure the reflectance characteristics of non-traditional blackbodies over a wide range of illumination and observation geometries. Key elements of the design, development, and validation of this system along with an example of its ability to validate a ray-trace model will be presented.
Gonio-Reflectometer for the Characterization of Advanced Blackbody Designs
The combination of high emissivity requirements and volume constraints has led to the development of space-flight blackbody designs exhibiting anisotropic emission characteristics. While generally isotropic over some nominal range the behavior of these blackbodies at greater off-nominal angles is complex and small errors in design or fabrication could cause unwanted characteristics. The performance of these designs is assessed with optical models but the optical models themselves need to be validated with laboratory measurements. To perform this validation ATK-Military Systems and Ball Aerospace have developed a gonio-reflectometer to measure the reflectance characteristics of non-traditional blackbodies over a wide range of illumination and observation geometries. Key elements of the design, development, and validation of this system along with an example of its ability to validate a ray-trace model will be presented.