ESTABLISHING BRDF CALIBRATION CAPABILITIES THROUGH SHORTWAVE INFRARED

Published

September 5, 2017

Author(s)

Catherine C. Cooksey, Georgi T. Georgiev, James Butler, Kurtis J. Thome, Leibo Ding

Abstract

Satellite instruments operating in the reflective solar wavelength region require accurate and precise determination of the Bidirectional Reflectance Distribution Functions (BRDFs) of the laboratory and flight diffusers used in their pre-flight and on-orbit calibrations. This paper advances that initial work and presents a comparison of spectral Bidirectional Reflectance Distribution Function (BRDF) and Directional Hemispherical Reflectance (DHR) of Spectralon*, a common material for laboratory and on-orbit flight diffusers. A new measurement setup for BRDF measurements from 900 nm to 2500 nm located at NASA Goddard Space Flight Center (GSFC) is described. The GSFC setup employs an extended indium gallium arsenide detector, bandpass filters, and a supercontinuum light source. Comparisons of the GSFC BRDF measurements in the shortwave infrared (SWIR) with those made by the National Institute of Standards and Technology (NIST) Spectral Tri-function Automated Reference Reflectometer (STARR) are presented. The Spectralon sample used in this study was 2 inch diameter, 99% white pressed and sintered Polytetrafluoroethylene (PTFE) target. The NASA/NIST BRDF comparison measurements were made at an incident angle of 0o and viewing angle of 45o. Additional BRDF data not compared to NIST were measured at additional incident and viewing angle geometries. The total combined uncertainty for BRDF in the SWIR range is less than 1% (k = 1). This study is in support of Radiation Budget Instrument (RBI) and Visible Infrared Imaging Radiometer Suit (VIIRS) of Joint Polar Satellite System (JPSS) radiometric calibration and other current and future NASA remote sensing missions operating across the reflected solar wavelength region.

Citation

Proceedings of SPIE

Volume

10402

Pub Type

Journals

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Keywords

BRDF, Calibration, RBI, JPSS, Reflectance, Remote Sensing

Citation

Cooksey, C. , Georgiev, G. , Butler, J. , Thome, K. and Ding, L. (2017), ESTABLISHING BRDF CALIBRATION CAPABILITIES THROUGH SHORTWAVE INFRARED, Proceedings of SPIE, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=923742 (Accessed January 2, 2025)