Summary

Description

This map layer includes Global Map data showing elevation for Alaska west of the 180th meridian, in meters relative to mean sea level. The data are a modified version of the National Atlas of the United States 100-Meter Resolution Elevation of Alaska. To comply with Global Map requirements, the National Atlas 100-meter Elevation data were reprojected to WGS84 Geographics, the values for oceans and non-U.S. land were adjusted, and the data were saved in Band-Interleaved-by-Line (BIL) format. The National Atlas source elevation data were derived from National Elevation Dataset (NED) data, http://ned.usgs.gov, and show the terrain at a resolution of 100 meters. The NED is a raster product assembled by the U.S. Geological Survey, designed to provide national elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections made in the NED assembly process minimize artifacts, permit edge matching, and fill sliver areas of missing data. The NED is updated on a bi-monthly basis.