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What data sources are used to produce the 3D Elevation Program (3DEP) DEMs?

The USGS 3D Elevation Program (3DEP) is in the process of collecting high-quality lidar and IfSAR (for Alaska) coverage for all of the United States and its territories. As this new data becomes available, legacy Digital Elevation Models (DEMs) are being systematically replaced with high-resolution DEMs produced almost entirely from the lidar and ifsar data.  

Legacy DEMs were produced from sources that include older lidar technology, cartographic contours derived from hand-drawn topographic maps, and Shuttle Radar Topography Mission (SRTM) elevation data.  

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