National Elevation Dataset - NED

The National Elevation Dataset (NED) is a digital elevation model of the United States that provides seamless and high-quality terrain information for various applications such as floodplain mapping, land management, and natural resource conservation. The NED is created and maintained by the US Geological Survey (USGS) and is publicly available free of charge.

The NED is a composite of multiple elevation data sources, such as topographic maps, lidar, and satellite data, that are processed to create a seamless and consistent elevation model for the entire United States. The data is provided in a raster format with a cell size of 1 arc-second (approximately 30 meters at the equator) and a vertical accuracy of about 1 meter. The NED data is available in various formats, including GeoTIFF, ArcGrid, and ERDAS Imagine.

The NED is widely used by government agencies, private companies, and researchers for various applications, such as natural resource management, floodplain mapping, emergency response planning, and infrastructure development. The NED is also an essential component of the National Spatial Data Infrastructure (NSDI) and is used as a base layer for many other geospatial datasets and applications in the United States.