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The Extension of the NIST BRDF Scale from 1100 nm to 2500 nm
Published
Author(s)
Howard W. Yoon, David W. Allen, George P. Eppeldauer, Benjamin K. Tsai
Abstract
Measurements of bi-directional reflectance factor for diffuse reflectance from 1100 nm to 2500 nm using extended-range indium gallium arsenide (exInGaAs) detectors in the NIST Spectral Tri-function Automated Reference Reflectometer (STARR) facility are described. The determination of bi-directional reflectance factor with low uncertainties requires the exInGaAs radiometer to be characterized for low-noise performance, linearity and spatial uniformity. The instrument characterizations will be used to establish a total uncertainty budget for the reflectance factor. To independently check the bi-directional reflectance factors, measurements also were made in a separate facility in which the reflectance factor is determined using calibrated spectral irradiance and radiance standards. The total combined uncertainties for the diffuse reflectances range from < 1 % at 1100 nm to 2.5 % at 2500 nm. At NIST, these measurement capabilities will evolve into a calibration service for diffuse spectral reflectance in this wavelength region.
Yoon, H.
, Allen, D.
, Eppeldauer, G.
and Tsai, B.
(2009),
The Extension of the NIST BRDF Scale from 1100 nm to 2500 nm, SPIE, San Diego, CA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=904078
(Accessed October 14, 2025)