The dataset is available to download in Geotiff format at a resolution of 30 arc-second (approximately 1Km at the equator). The 1km resolution global boundaries were produced from the 100m national boundaries. The projection is Geographic Coordinate System, WGS84. Grid cell values represent International Standard 3-digit numerical ISO 3166 Country Codes corresponding to country and territory names as designated by the United Nations (ISO, 2017). It is important to note that these data are not official representations of country boundaries, some of which are disputed, but simply represent the source of the population count data.
WorldPop (www.worldpop.org - School of Geography and Environmental Science, University of Southampton; Department of Geography and Geosciences, University of Louisville; Departement de Geographie, Universite de Namur) and Center for International Earth Science Information Network (CIESIN), Columbia University (2018). Global High Resolution Population Denominators Project - Funded by The Bill and Melinda Gates Foundation (OPP1134076)