GMTED2010 – Global Multi-resolution Terrain Elevation Data
The USGS has global DEM data at several resolution levels: 30-arc-second (1 kilometer), 15-arc-second (450 meters), and 7.5-arc-second (225 meters). The GMTED2010 dataset with multiple resolution levels replaces a former version called GTOPO30, which only had the resolution level of 30-arc-second (1 kilometer). These data have been collected from a variety of sources using aggregation methods. These datasets are best used for working at the continental scale and with very large regions.