^aGLCC organization (The Global Land Cover Characterization (GLCC) is a series of the global land cover classification datasets that are primarily based on the unsupervised classification of 1-km AVHRR (Advanced Very High Resolution Radiometer) 10-day NDVI (Normalized Difference Vegetation Index) composites. The AVHRR source imagery dates from April 1992 through March 1993. The Ancillary data sources included the digital elevation data, the eco-regions interpretation, the country- or regional-level vegetation, and the land cover maps. https://lta.cr.usgs.gov/GLCC