Optical studies of low reflectance materials at solar reflective wavelengths in support of remote sensing instrument development and calibration

Autor: William B. Cook, Nathan Kelley, James J. Butler, Xiaoxiong Xiong, Jinan Zeng
Rok vydání: 2019
Předmět:
Zdroj: Earth Observing Systems XXIV.
Popis: We report the Bidirectional Reflection Distribution Function (BRDF) and Total Hemispheric Reflectance (THR) results of several low reflectance materials using a Table-top Goniometer (TTG) and a commercial UV-VIS-NIR spectrophotometer in support of the NASA GSFC PACE project. The newly developed TTG was utilized to perform the BRDF measurements for several black candidate samples in in-plane and out-of-plane configurations from 300 nm to 2000 nm. These measurements demonstrated the BRDF capability of the TTG to calibrate the dim calibration target with a reflectance of approximately 2 % for the OCI of the PACE project. The spectral THR of the black samples from 200 nm to 2500 nm was determined using a 10 % reflectance diffuse black standard and a monochromator-based light source equipped with a 150 mm diameter integrating sphere. The THR measurement is used to compliment and validate the BRDF measurements acquired from these samples. In this presentation, we also show examples of UV induced BRDF and THR changes on two black coatings. We will discuss validation of the BRDF scale, source stability, measurement repeatability, instrument signature, and uncertainty components.
Databáze: OpenAIRE