Spatial distributions of geo-referenced field photos and ground reference data for accuracy assessment of forest maps in Australia. (a) Geo-referenced field photos in Australia, which is freely available from the Global Geo-Referenced Field Photo Library, the University of Oklahoma (http://www.eomf.ou.edu/photos/
). There is no field photo in Tasmania. (b) Ground reference data for forest and nonforest land cover types came from visual interpretation of very high spatial resolution images in Google Earth around 2010.