Elevation

The National Elevation Dataset (NED) is a seamless raster product primarily derived from USGS 10- and 30-meter Digital Elevation Models (DEMs), and, increasingly, from higher resolution data sources such as Light Detection and Ranging (LIDAR), Interferometric Synthetic Aperture Radar (IFSAR), and high-resolution imagery. NED data are available as 1 arc-second (approximately 30 meters) for the conterminous United States, and at 1/3 and 1/9 arc-seconds (approximately 10 and 3 meters, respectively) for parts of the United States. NED resolution for Alaska primarily is 2 arc-seconds (approximately 60 meters). Further information and data download are available at: http://ned.usgs.gov/.