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ned
National Elevation Dataset
(NED)
The National Elevation Dataset (NED) has been developed
by merging the highest-resolution, best-quality elevation
data available across the United States. NED is the result
of the maturation of the USGS effort to provide 1:24,000-scale
Digital Elevation Model (DEM) data for the conterminous
US and 1:63,360-scale DEM data for Alaska. It has a resolution
of one arc-second (approximately 30 meters) for the conterminous
United States, Hawaii, and Puerto Rico and a resolution
of two arc-seconds for Alaska. NED is designed to provide
National elevation data in a seamless raster format with
a consistent datum, elevation unit, and projection. Data
corrections were made in the NED assembly process to minimize
artifacts, perform edge matching, and fill sliver areas
of missing data. These processing steps ensure that NED
has no void areas and artificial discontinuities have been
minimized. As higher-resolution or higher-quality data become
available, the NED is periodically updated to incorporate
best-available coverage. Also, as more data become available
at a finer resolution than NED, the feasibility of developing
a finer resolution NED will be investigated.
For more information on the National Elevation Dataset,
see http://edcnts12.cr.usgs.gov/ned.
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