NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Far-infrared /FIR/ optical black bidirectional reflectance distribution function /BRDF/A nonspecular reflectometer and its operation at far-infrared wavelengths are described. Large differences in nonspecular reflectance were found to exist between different optically black coatings. Normal incidence bidirectional reflectance distribution function /BRDF) measurements at wavelengths between 12 and 316 microns of three black coatings show that their mean BRDFs increase with wavelength. The specularity of two of these coatings also showed a strong wavelength dependence, while the specularity of one coating seemed independent of wavelength. The BRDF of one coating depended on the angle of incidence at 12 and 38 microns, but not at 316 microns. Beyond 200 microns, it was found necessary to correct the measurements for the beam spread of the instrument.
Document ID
19810052491
Document Type
Conference Proceedings
Authors
Smith, S. M. (NASA Ames Research Center Moffett Field, Calif., United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1981
Subject Category
OPTICS
Meeting Information
Seminar on Radiation scattering in optical systems(Huntsville, AL)
Distribution Limits
Public
Copyright
Other