3D Elevation Program (3DEP)

Program Benefits and Uses

Benefits

3DEP can conservatively provide new benefits of $690 million per year and has the potential to generate $13 billion per year in new benefits through applications that span the economy (Dewberry, 2012). The shared lidar, IfSAR, and derived elevation datasets would foster cooperation and improve decisionmaking among all levels of government and other stakeholders.

♦ Reduced Acquisition Costs and Risks

A funded national program will provide the following:

  • Economy of scale by acquiring data for larger areas and reducing acquisition costs by 25 percent.
  • Predictable, efficient, and flexible Federal investments that reduce costs for and allow better planning by Federal, State, Tribal, U.S. territorial, and local government partners, including the option of “buying up” to acquire higher quality data.
  • Consistent, high-quality national coverage that (1) provides data ready for applications that span project, jurisdictional, and watershed boundaries, (2) meets multiple needs, and (3) increases benefits to citizens.
  • Simpler data acquisition that provides contracts, published data-acquisition specifications, and specialized quality assurance and information technology expertise. Partners reduce their risks and can concentrate on their business activities.

 

♦ High-Quality Data

For the conterminous United States, Hawaii, and the U.S. territories, the USGS and its partners acquire quality level 2 or better aerial lidar data. Quality level 2 data have a minimum nominal pulse spacing of 0.7 meters and a vertical error of 10 centimeters, measured as root mean square error in the elevation (z) dimension (RMSEz). Statewide for Alaska, quality level 5 IfSAR data are acquired that have a vertical error of 185 centimeters RMSEz. The data must have been acquired during the previous eight years. For more information, see the Lidar Base Specification available at http://pubs.usgs.gov/tm/11b4/.

♦ Point Cloud and Derived Products

Lidar data products include the all-return classified point clouds and derived bare-earth DEMs. Each DEM dataset is identified by its horizontal resolution and is produced to a consistent set of specifications. All DEMs represent the topographic surface of the Earth and contain flattened water surfaces. Nationally seamless DEMs are produced by blending only the highest quality project data into a continuous terrain surface for the United States, and are published at resolutions of 1/3 arc-second, 1 arc-second, and 2 arc-seconds. The standard 1-meter DEM dataset is seamless within collection projects but not across projects.

IfSAR data in Alaska include digital surface models, orthorectified intensity images, and 5-meter-resolution hydro-flattened DEMs.

The USGS integrates the elevation model data into its national elevation data coverage, as a component of The National Map. All 3DEP products to include an elevation-point query service and bulk-point query service are components of The National Map. Data are available, free of charge and without use restrictions. To download 3DEP products visit http://viewer.nationalmap.gov/basic/