This map includes a variety of Landsat services where the NDVI Change has been calculated to compare different time periods.This change is generated by combining multi-temporal imagery of Landsat GLS NDVI. Most areas in the image will be grey, indicating no change because each pixel has relatively the same value in each band. Areas that show up green increased in brightness, while areas that show up in magenta decreased in brightness.
Data Source: This map includes image services compiled from the following Global Land Survey (GLS) datasets: GLS 2005, GLS 2000, GLS 1990, and GLS 1975. GLS datasets are created by the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA) using Landsat images. These global minimal-cloud cover, orthorectified Landsat data products support global assessments of land-cover, land cover-change, and ecosystem dynamics such as disturbance and vegetation health.
Global Land Survey (GLS) - http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/GLS