Other 3DEP products include five-meter DEMs in Alaska as well as various source datasets including the lidar point cloud and interferometric synthetic aperture radar (Ifsar) digital surface models and intensity images. These seamless DEMs were referred to as the National Elevation Dataset (NED) from about 2000 through 2015 at which time they became the seamless DEM layers under the 3DEP program and lost the NED branding. Other 3DEP products are nationally seamless DEMs in resolutions of 1/3, 1, and 2 arc seconds. The one-meter DEM is the highest resolution standard DEM offered in the 3DEP product suite. If a tile crosses two UTM zones, it is delivered in both zones. Each tile is distributed in the UTM Zone in which it lies. All bare earth elevation values are in meters and are referenced to the North American Vertical Datum of 1988 (NAVD88). In some countries, digital elevation model is synonymous with digital. The terrain model contains information about the height without considering vegetation, buildings, and other objects. 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). A digital terrain model (DTM or DEM) is a three-dimensional representation of the earth's surface, represented as an array of points with a defined height. One-meter DEM surfaces are seamless within collection projects, but, not necessarily seamless across projects. Primarily, the data will be 1 foot resolution in a 5000' x 5000' tiling scheme using the State Plane Coordinate System. The High Resolution Orthoimagery collection has been acquired in partnerships with other state, or regional agencies. USGS standard one-meter DEMs are produced exclusively from high resolution light detection and ranging (lidar) source data of one-meter or higher resolution. Florida Statewide Base Digital Orthophoto Program. The elevations in this DEM represent the topographic bare-earth surface. This is a tile of the standard one-meter resolution digital elevation model (DEM) produced through the 3D Elevation Program (3DEP).