Translator Disclaimer
5 September 2017 Spectralon solar diffuser BRDF variation for NPP, JPSS J1 and J2
Author Affiliations +
The Visible/Infrared Imaging Radiometer Suite (VIIRS) is a key sensor on the Suomi National Polar-orbiting Partnership (NPP) satellite as well as the upcoming Joint Polar Satellite System (JPSS). VIIRS collects Earth radiometric and imagery data in 22 spectral bands from 0.4 to 12.5 μm. Radiometric calibration of the reflective bands in the 0.4 to 2.5 μm wavelength range is performed by measuring the sunlight reflectance from Spectralon®. Reflected sun light is directly proportional to the Bidirectional Reflectance Distribution Function (BRDF) of the Spectralon. This paper presents the BRDF measurements of the Spectralon for JPSS J2 in the 0.4 – 1.63 μm wavelength using PASCAL (Polarization And Scatter Characterization Analysis of Lambertian materials) with an uncertainty better than 1.2%. PASCAL makes absolute measurements of the BRDF in an analogous fashion to the National Institute of Standards and Technology (NIST) Spectral Tri-function Automated Reflectance Reflectometer (STARR) facility. Unique additional features of this instrument include the ability to vary the sample elevation and roll / clock the sample about its normal, allowing measurement of BRDF in the as used geometry. Comparison of BRDF in the as used configuration for NPP, J1, and J2 shows variation of up to 3%. The sign of the change from panel to panel depends on the angle of incidence and view angle. The results demonstrate lot to lot variability in Spectralon and emphasize the necessity of characterizing each panel. A pattern in the BRDF variation is also presented.
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Vijay Murgai, Lindsay Johnson, and Staci Klein "Spectralon solar diffuser BRDF variation for NPP, JPSS J1 and J2", Proc. SPIE 10402, Earth Observing Systems XXII, 104021M (5 September 2017);

Back to Top