| Author(s): |
Howard W. Yoon; David W. Allen; George P. Eppeldauer; Benjamin K. Tsai; |
| Title: |
The Extension of the NIST BRDF Scale from 1100 nm to 2500 nm |
| Published: |
August 21, 2009 |
| 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. |
| Proceedings: |
SPIE |
| Location: |
San Diego, CA |
| Dates: |
August 3-7, 2009 |
| Keywords: |
Absolute Reflectance; Bi-Directional Reflectance Factors; Infrared; Pressed PTFE |
| Research Areas: |
Optical Properties of Materials |
| PDF version: |
 Click here to retrieve PDF version of paper (160KB) |
