Aspect represents the azimuth of the sloped surfaces across a landscape. Aspect is generated from ⅓ arc-second Digital Elevation Models (DEM), previously referred to as the National Elevation Dataset (NED). The ⅓ arc-second DEM is part of the USGS 3D Elevation Program (3DEP), which provides the best available public domain raster elevation data of the conterminous United States, Alaska, Hawaii, and insular areas in a seamless format. The 3DEP ⅓ arc-second DEMs are derived from diverse source data, processed to a common coordinate system and unit of vertical measure.
LF 2016 Remap for Alaska (AK) includes a 90-kilometer buffer along the 1,500 miles of the eastern and southern borders AK shares with Canada.