VNP46A4 - VIIRS/NPP Lunar BRDF-Adjusted Nighttime Lights Yearly L3 Global 15 arc second Linear Lat Lon Grid

The Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) supports a Day-Night Band (DNB) sensor that provides global daily measurements of nocturnal visible and near-infrared (NIR) light that are suitable for Earth system science and applications. The VIIRS DNB's ultra-sensitivity in lowlight conditions enable us to generate a new set of science-quality nighttime products that manifest substantial improvements in sensor resolution and calibration when compared to the previous era of Defense Meteorological Satellite Program/Operational Linescan System's (DMSP/OLS) nighttime lights image products. Such improvements allow the VIIRS DNB products to better monitor both the magnitude and signature of nighttime phenomena, and anthropogenic sources of light emissions.

VNP46A4 is the short-name for the fourth nighttime lights (NTL) product in the Black Marble suite, which provides yearly composites generated from daily atmospherically- and lunar-BRDF-corrected NTL radiance to remove the influence of extraneous artifacts and biases. Known by its long-name, VIIRS/NPP Lunar BRDF-Adjusted Nighttime Lights Yearly L3 Global 15 arc-second Linear Lat Lon Grid, this product contains 28 layers. They provide information on the NTL composite, the number of observations, quality, and standard deviation for multi-view zenith angle categories (near-nadir, off-nadir, and all angles), their snow-covered and snow-free statuses besides land-water mask, latitude and longitude coordinate information. They also include detailed information and description of the quality flags. This SNPP VIIRS collection-1 product record, identified by its version-ID 001 in its file name, starts from January 1st 2012.

Processing Chain Provenance
This section instructs users regarding where to find the source locations for three provenance-specific information artifacts in the global metadata attributes.

Processing steps used to generate the SNPP VIIRS VNP46 product: The data product inputs, the algorithm processing flow, and all other pertinent details that help create the VIIRS Nighttime Lights products are described in the following two sources:

1. The Black Marble User Guide (Version 1.2, September 2022)
2. The Black Marble Algorithm Theoretical Basis Document (Version 1.1, July 2020)

The data producer's name and email: This information does not currently exist in the global metadata attributes, and is slated for addition in the next reprocessing cycle.

The production software (PGE) version used: The processing software used to generate the product is called a Product Generation Executable or PGE, and is identified via the following two pieces of information in the global metadata attributes:

1. PGE_Name, which is an alphanumeric value, e.g., “PGE554”
2. PGE Version, which is a numeric value, e.g., “1.0.10”

The PGE name and its version help associate the exact production software that was used to generate any specific version of the data product.