NASA’s Black Marble Multiangle Nighttime Lights Temporal Composites
Zhuosen Wang, Ranjay Shrestha, Miguel O. Román, Virginia Kalb
Abstract
In addition to the daily Black Marble products (VNP46A1/A2), the recently released temporal composite products (VNP46A3/A4) are generated from daily high-quality, atmospheric, and lunar-Bidirectional Reflectance Distribution Function (BRDF) corrected, Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) nighttime radiances (VNP46A2). This letter describes the algorithm of NASA’s Black Marble monthly and annual (VNP46A3/A4) Nighttime Light (NTL) composites that are operationally produced for multiple view angle categories and snow conditions, along with ancillary metrics and mandatory quality assurance flags. Boxplot metrics are calculated to systematically remove outliers and minimize reliance on empirical or regional thresholds. VNP46A3/A4 products represent all nighttime conditions (i.e., moon-lit and moon-free periods), leading to an increased number of high-quality observations. To fully make use of the VIIRS DNB’s wide-swath (3040 km), both VNP46A3/A4 are generated for three view zenith angle categories (near-nadir, off-nadir, and all-angles) and two different snow conditions (snow-free and snow-covered). The introduction of global multidirectional data should be of interest to the scientific and applications communities. In particular, they can enable standardized intercomparisons across NTL products and allow a greater capability to track additional dimensions of NTL change, including the intrinsic characteristics of human settlements and their infrastructure. VNP46A3/A4 products are currently made available retrospectively via NASA’s Level-1 and Atmosphere Archive and Distribution System (LAADS) from the start of the Suomi-National Polar-orbiting Partnership (S-NPP) mission period (c. January 2012).