Vegetation indices

eMODIS NDVI 10-daily data (Africa)

eMODIS are taken from the FEWS NET data portal and imported in Spirits format.
All credits go to: U.S. Geological Survey – Department of the Interior/USGS

The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center distributes a collection of satellite-derived vegetation products generated from the Moderate Resolution Imaging Spectroradiometer (MODIS). These products, known as “eMODIS,” respond to operational land monitoring applications requiring near-real time Normalized Difference Vegetation Index (NDVI) data for comparison against historical records. Real-time and historical NDVI products are composited and temporally smoothed in 10-day intervals at 250m spatial resolution. The complete documentation can be found at the original data provider (FEWS NET) dissemination page.

Images are temporally smoothed to improve the quality of data, but as it is problematic to implement in real time for areas of persistent cloud cover, the last three images (i.e. last month) are recalculated once new images become available. The temporary version of the last three dekads is marked by the suffix “_m” and is replaced by the final version as soon as it is generated. Given the size of the dataset, Africa is divided in 4 tiles (North, West, East, Southern), as illustrated in the image below.

Raw data
Long term average (2001-2013)