GC22B-04
Lunar BRDF Correction of Suomi-NPP VIIRS Day/Night Band Time Series Product
Tuesday, 15 December 2015: 11:05
3022 (Moscone West)
Zhuosen Wang1, Miguel O Roman1, Virginia Kalb1, Eleanor Stokes2 and Steven D Miller3, (1)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (2)Yale University, School of Forestry and Environmental Studies, New Haven, CT, United States, (3)Cooperative Institute for Research in the Atmosphere, Fort Collins, CO, United States
Abstract:
Since the first-light images from the Suomi-NPP VIIRS low-light visible Day/Night Band (DNB) sensor were received in November 2011, the NASA Suomi-NPP Land Science Investigator Processing System (SIPS) has focused on evaluating this new capability for quantitative science applications, as well as developing and testing refined algorithms to meet operational and Land science research needs. While many promising DNB applications have been developed since the Suomi-NPP launch, most studies to-date have been limited by the traditional qualitative image display and spatial-temporal aggregated statistical analysis methods inherent in current heritage algorithms. This has resulted in strong interest for a new generation of science-quality products that can be used to monitor both the magnitude and signature of nighttime phenomena and anthropogenic sources of light emissions. In one particular case study, Román and Stokes (2015) demonstrated that tracking daily dynamic DNB radiances can provide valuable information about the character of the human activities and behaviors that influence energy, consumption, and vulnerability. Here we develop and evaluate a new suite of DNB science-quality algorithms that can exclude a primary source of background noise: i.e., the Lunar BRDF (Bidirectional Reflectance Distribution Function) effect. Every day, the operational NASA Land SIPS DNB algorithm makes use of 16 days worth of DNB-derived surface reflectances (SR) (based on the heritage MODIS SR algorithm) and a semiempirical kernel-driven bidirectional reflectance model to determine a global set of parameters describing the BRDF of the land surface. The nighttime period of interest is heavily weighted as a function of observation coverage. These gridded parameters, combined with Miller and Turner’s [2009] top-of-atmosphere spectral irradiance model, are then used to determine the DNB’s lunar radiance contribution at any point in time and under specific illumination conditions.
