National Digital Elevation Program Guidelines

http://www.ndep.gov/NDEP_Elevation_Guidelines_Ver1_10May2004.pdf

The purpose of this document is to provide the member agencies of the National Digital Elevation Program (NDEP), as well as nonmember agencies, with guidelines and recommendations for acquiring digital elevation data in any of its various forms. Individual agencies may choose from flexible options to establish standards for their organizations. The following reasons are commonly cited for promoting and adhering to a common set of elevation guidelines or standards whenever possible and practical.