Table 1 Input datasets.

From: A suite of global accessibility indicators

Data Spatial resolution Values Projection Geographic extent Temporal reference Format Source
GHS settlement grid, following the REGIO model 2014 in application to GHSL Landsat and CIESIN GPW v4-multitemporal (1975-1990-2000-2015) 1 km Pixel values represent the type of settlement World Mollweide (EPSG:54009) Global 2015 GeoTIFF
GHS population grid, derived from GPW4, multitemporal (1975, 1990, 2000, 2015) 30 arc seconds Population counts WGS84 (EPSG:4326) Global 2015 GeoTIFF
Friction surface 30 arc seconds Time required to cross each pixel in minutes per metre WGS84 (EPSG:4326) Global 2015 GeoTIFF
Land mask based on Global Administrative Boundaries Dataset (GADM) v3.61 30 arc seconds Binary mask of land/no land WGS84 (EPSG:4326) Global NA GeoTIFF