Elevation data

You’re likeliest to run into one of these two main data formats used to represent elevation:

• Digital Elevation Model (DEM): The USGS uses this raster data format to record elevation information (based on topographic maps) and create three-dimensional representations of the terrain.
• National Elevation Dataset (NED): This format shows digital elevation data in shaded relief. It’s designed for seamless coverage of the United States in large raster files.