Global MODIS 500-m Maps of Urban Extent

Investigators have developed a new data set depicting global urban land c. 2001-2002 based on Moderate Resolution Imaging Spectroradiometer (MODIS) 500-m satellite data. Their methods exploit temporal and spectral information in one year of MODIS observations, classified using an ensemble decision tree classification approach. The data are provided for two different classification schemes: (1) Global Urban Extent (class 13), including land (class 1) and water (class 0) information; and (2) Global IGBP Land Cover Map (classes 1-17), including urban extent (class 13). In both data sets, urban areas (coded class 13) are defined based on physical attributes: urban areas are places that are dominated by the built environment. The �built environment� includes all non-vegetative, human-constructed elements, such as buildings, roads, runways, etc. (i.e., a mix of human-made surfaces and materials), and �dominated� implies coverage greater than or equal to 50 percent of a given landscape unit (here, the pixel). Pixels that are predominantly vegetated (e.g., a park) are not considered urban, even though in terms of land use, they may function as urban space. A minimum mapping unit is defined: urban areas are contiguous patches of built-up land greater than 1 km 2. The data are provided in three different projected coordinate systems: Native Sinusoidal projection; Geographic projection (latitude, longitude); and Interrupted Goode�s Homolosine projection. See the README for details. For additional information, please see Schneider, A., M. A. Friedl and D. Potere. 2009 A new map of global urban extent from MODIS data. Environmental Research Letters, volume 4, article 044003, and Schneider, A., M. A. Friedl and D. Potere. 2010. Monitoring urban areas globally using MODIS 500m data: New methods and datasets based on urban ecoregions. Remote Sensing of Environment, vol. 114, p. 1733-1746.