National Elevation Dataset
The Federal Geographic Data Committee's content standard for digital geospatial metadata (http://www.fgdc.gov/metadata/csdgm/) is used to document NED data. Metadata about the individual source datasets used to assemble the NED is presented in a spatially-referenced form. The polygon footprint of each portion used from a source dataset is retained during the NED assembly to provide the spatial context. The attributes of each source dataset, such as original spatial resolution, production method, and date entered into the NED, are linked to this polygon footprint. All of these source polygons together form a seamless National coverage. Through this spatially-referenced metadata, the information is made available to the user regarding the source data used for any area of the NED. For example, a NED data user might use the spatially-referenced metadata to identify the portions of a study area that were produced by a specific production method.
Spatial Metadata located on FTP site: http://ned.usgs.gov/downloads.html