VIIRS Vegetation Index (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 TOA NDVI, the TOC NDVI, the TOC EVI, and relevant quality flags (i.e., Land/water mask, cloud confidence, aerosol loadings and exclusion conditions).
The Green Vegetation Fraction (GVF) system was developed to generate GVF as a NOAA-Unique Product (NUP) from data from the Visible Infrared Imager Radiometer Suite (VIIRS) sensor onboard Suomi National Polar-orbiting Partnership (SNPP) satellite and NOAA-20 (j01) satellite, for applications in numerical weather and seasonal climate prediction models at the National Centers for Environmental Prediction (NCEP). The retrieval algorithm uses VIIRS red (I1), near-infrared (I2) and blue (M3) bands centered at 0.640 μm, 0.865 µm and 0.490 µm respectively, to calculate the Enhanced Vegetation Index (EVI) and derive GVF from EVI. GVF will be produced as a daily rolling weekly composite at 4-km resolution (global scale) and 1-km resolution (regional scale).
The VIIRS Vegetation Health Product (VVHP) is gridded weekly global vegetation indices (Vegetation Condition Index (VCI), Temperature Condition Index (TCI) and Vegetation Health Index (VHI).) derived from VIIRS Scientific Data Records (SDR) for the global area between latitude 55°S to 75°N. The projection of VHP product is Plate Carree projection (geographic projection, a grid with equal latitude-longitude interval). The interval of grid is 0.009° (about 1km at equator). Noise is minimized by applying the time series smoothing technique and other correction algorithms.