Vegetation Products

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 third generation polar Global Vegetation Index (GVI) products are used for monitoring the density and vigor of green vegetation. Useful applications of GVI products include classifying land cover, estimating crop acreage, and detecting plant stress. The GVI operational products are weekly composites, and have a resolution of about 16 km. A comprehensive description of GVI products may be found at the national Climatic Data Center's NOAA GVI Guide.

Products include:
• Normalized Difference Vegetation Index (NDVI): a calculation of the differences between AVHRR channels 1 and 2
•  Fractional Vegetation: NDVI displayed as a fraction
• Precipitable Water Index: a measurement of how much water vapor is in the atmosphere

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 MetOp Global Vegetation Index (MGVI) product is used for monitoring the density and vigor of green vegetation. Useful applications of GVI products include classifying land cover, estimating crop acreage, and detecting plant stress. The weekly composite MetOp Global Vegetation Index (MGVI) is derived from MetOp AVHRR global 16 km FRAC data. When the daily map is created, the most nadir pixel is selected. The weekly composite product is created from daily maps of 7 days on pixel basis by selecting the data of the day with Maximum NDVI.

Product:
• Normalized Difference Vegetation Index (NDVI)

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. Details on the algorithm can be found at Algorithm Description.

Products include:
• Temperature Condition Index
• Vegetation Condition Index
• Vegetative Health Index
• TIF Files on FTP Server

The VIIRS Surface Reflectance Product (VIIRS SR) is generated in near-real time from the VIIRS SDR product and auxiliary products from the NDE framework. The output products include surface reflectance for three imagery bands and nine moderate bands. Output also includes five bytes of quality flags, which are each bitmasks representing various properties of both inputs and outputs.

Products include:
• VIIRS Surface Reflectance Band M1
• VIIRS Surface Reflectance Band M3
• PNG Files on FTP Server
• NPP Data Exploitation Vegetation Processing System (NDE)