“…High resolution satellite data provide the only practical source of reference data for this global 500-sample-block dataset . Such use of relatively finer resolution satellite data as the basis of or as a component of global and large area land cover accuracy assessment has been established (Bontemps et al, 2012;De Fries, Hansen, Townshend, & Sohlberg, 1998;Desclee, Simonetti, Mayaux, & Achard, 2013;Mayaux et al, 2006;Montesano et al, 2009;Morisette et al, 2003;Petropoulos, Partsinevelos, & Mitraka, 2013;Raši et al, 2011;Scepan & Estes, 2001;Small & Lu, 2006). Our purpose in this article is to document the identification, collection and preprocessing of reference source-data, the reference map production, and the methods used in applying these high resolution thematic data to assess 30 m continuous field data layers characterizing global tree cover.…”