Fact Sheet 2009–3053 National Elevation Dataset The National
Elevation Dataset (NED) is the primary elevation data product
produced and distributed by the USGS. The NED provides seamless
raster elevation data of the conterminous United States, Alaska,
Hawaii, and the island territories. The NED is derived from
diverse source data sets that are processed to a specification
with a consistent resolution, coordinate system, elevation
units, and horizontal and vertical datums. The NED is the
logical result of the maturation of the long-standing USGS
elevation program, which for many years concentrated on
production of topographic map quadrangle-based digital elevation
models. The NED serves as the elevation layer of The National
Map, and provides basic elevation information for earth science
studies and mapping applications in the United States. The NED
is a multi-resolution dataset that is updated bimonthly to
integrate newly available, improved elevation source data. NED
data are available nationally at grid spa