VIIRS Vegetation Index (VI) Product System

VIIRS Vegetation Index (VI) is a robust empirical measure of vegetation activity at the land surface, and has been widely used to study the spatial and temporal pattern of vegetation conditions at large scale with the objective to understand the role of terrestrial vegetation in regional and global processes, such as global carbon and nitrogen cycle, global hydrological cycle and global energy cycle.

The VIIRS VI product system produces gridded VI product at global scale and North America- centric regional scale from S-NPP VIIRS granule data and J01 VIIRS granule data, which contains the Top of the Atmosphere (TOA) Normalized Difference Vegetation Index (NDVI), the Top of the Canopy (TOC) NDVI, the TOC Enhanced Vegetation Index (EVI), and relevant quality flags (i.e., Land/water mask, cloud confidence, aerosol loadings and exclusion conditions). Meanwhile, quality assurances (QA) of the VI products are generated to consider impact of various environmental factors (e.g., cloudy, sun glint, aerosol). These VI products are produced at temporal scales of daily, weekly and bi-weekly at spatial resolutions with sizes of 4 km (0.036°, global scale) and 1km (0.009°, regional scale). For detailed information about the VI algorithm, see the VI Algorithm Theoretical Basis Document and to get an understanding of the calculations of the daily, weekly, and bi-weekly imagery, click here.

SNPP

TOA NDVI

Top of the Atmosphere (TOA) Normalized Difference Vegetation Index (NDVI) is calculated by using the aggregated TOA reflectance, which include TOA reflectance...

Local

Global

TOC NDVI

Top of the Canopy (TOC) Normalized Difference Vegetation Index (NDVI) is calculated by using the aggregated TOC reflectance, which include TOC reflectance in VIIRS...

Local

Global

TOC EVI

Top of the Canopy (TOC) Enhanced Vegetation Index (EVI) is calculated by using the aggregated TOC reflectance at 1-km and 4-km resolutions respectively...

Local

Global