Leading Edge Geomatics (LEG) collected 3451 square miles in Puerto Rico. The nominal pulse spacing for this project was 1 point every 0.7 meters. Dewberry used proprietary procedures to classify the LAS according to project specifications: 0-Never Classified, 1-Unclassified, 2-Ground, 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17-Bridges, 18-High Noise. USGS standard one-meter DEMs are produced exclusively from high resolution light detection and ranging (lidar) source data of one-meter or higher resolution. One-meter DEM surfaces are seamless within collection projects, but, not necessarily seamless across projects. The spatial reference used for tiles of the one-meter DEM within the conterminous United States (CONUS) is Universal Transverse Mercator (UTM) in units of meters, and in conformance with the North American Datum of 1983 (NAD83). Dec 24, 2020 · The seamless 1/3 arc-second DEM is available as pre-staged products tiled in 1 degree blocks in Erdas .img, ESRI arc-grid, and grid float formats. The seamless 1/3 arc-second DEM layer is updated continually as new data become available. Other 3DEP products are nationally seamless DEMs in resolutions of 1, and 2 arc seconds.