VIIRS/NPP Vegetation Indices Monthly L3 Global 1km SIN Grid V001

The VNP13A3 VIIRS Version 1 data product was decommissioned on April 8th, 2025. Users are encouraged to use Version 2 data products, which provide better calibration and consistency for the end user. VIIRS Version 2 data products are available from both the SNPP (VNP13A3) and NOAA-20 (VJ113A3) satellites. The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Vegetation Indices (VNP13A3) Version 1 data product provides vegetation indices by a process of selecting the best available pixel over a monthly acquisition period at 1 kilometer (km) resolution. The VNP13 data products are designed after the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua Vegetation Indices product suite to promote the continuity of the Earth Observation System (EOS) mission. The VNP13 algorithm process produces three vegetation indices: The Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI), and the Enhanced Vegetation Index-2 (EVI2). NDVI is one of the longest continual remotely sensed time series observations, using both the red and near-infrared (NIR) bands. EVI is a slightly different vegetation index that is more sensitive to canopy cover, while NDVI is more sensitive to chlorophyll. EVI2 is a reformation of the standard 3-band EVI, using the red band and NIR band. This reformation addresses arising issues when comparing VIIRS EVI to other EVI models that do not include a blue band. EVI2 will eventually become the standard EVI. Along with the three Vegetation Indices layers, this product also includes layers for NIR reflectance; three shortwave infrared (SWIR) reflectance; red, blue, and green reflectance; pixel reliability; pixel reliability; relative azimuth, view, and sun angles; and a quality layer. Two low resolution browse images are also available for each VNP13A3 product: EVI and NDVI. Known Issues * The incorrect representation of the aerosol quantities (low, average, high) in the VIIRS Land Surface Reflectance product (VNP09) may have impacted VNP13 Vegetation Index data products particularly over arid bright surfaces. * Corrections were implemented in 2023 with the release of the Version 2 Vegetation Index data products. Users are encouraged to use the improved Version 2 data. * For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.