The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey. The NED is a seamless mosaic of...
The 7.5-minute digital elevation model (DEM) data are digital representations of cartographic information in a raster form. The DEMs consists of...
These DEMs consist of an array of elevations for ground positions at regularly spaced 3-meter intervals. They were created from mass points and...
A Digital Raster Graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) topographic map. An unclipped scanned image includes all...