Projection Transformation

Entire USGS National Elevation Dataset Now Affordable

Projection transformation of the National Elevation Dataset was required to transform  
the 7.5-minute DEM data referenced horizontally in the UTM coordinate system to the geographic (latitude/longitude) coordinate system adopted for the NED dataset. 

The transformation is applied to the input elevation data, creating a 1-arc second dataset. 

Resampling of the 2-arc second and 3-arc second DEM's was necessary at this point to create coregistered data from all data sources at the 1-arc second resolution. 

A bilinear interpolation algorithm was used to perform the resampling. (courtesy of the USGS)

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Entire National Elevation Compressed on 2 DVD-ROM's

Entire US Census Bureau Tiger 2004 Dataset on 1 DVD-ROM