The 3D Elevation Program: Federal Best Practices for Nationwide Lidar Mapping

From a U.S. Geological Survey fact sheet of February 2021.

The 3D Elevation Program (3DEP) aims to complete nationwide data collection in 8 years, by 2023, giving the country its first national baseline of consistent, high-resolution three-dimensional data — bare-earth elevations and 3D point clouds — gathered in less than a decade.

Figure 1. From top to bottom: a bare-earth digital elevation model derived from lidar, a colorised point cloud, and a lidar profile, Olympia, Washington. Credit: U.S. Geological Survey.

Why elevation data matter

High-quality elevation data are critical to flood risk management, resource management, conservation, energy development, agriculture, infrastructure management, critical-minerals exploration and much else. The National Enhanced Elevation Assessment documented more than 600 business uses of elevation data across 34 federal agencies, all 50 states, some local and tribal governments, and private and non-profit organisations.

The USGS National Geospatial Program manages 3DEP for the whole community. Its main goal is to collect lidar data systematically, over 8 years, for the conterminous United States, Hawaii and the U.S. territories; for Alaska, where cloud and remoteness rule out lidar in much of the state, interferometric synthetic aperture radar (IfSAR) data have been acquired.

• Return. Based on the assessment's benefit-cost analysis, 3DEP is designed to return, conservatively, 5 to 1 on investment and million a year in new benefits, with the potential for billion a year across the economy.
• Support. The National Geospatial Advisory Committee (which advises the Federal Geographic Data Committee), the National States Geographic Information Council and more than 40 other professional organisations in the 3DEP Coalition have endorsed it.

Progress

3DEP began in 2012, with its first full year of production at the USGS in 2016. Since then its infrastructure and governance have been set up: federal coordination through the 3DEP Executive Forum and the operational 3DEP Working Group, and data collection through a Broad Agency Announcement process and federal partnerships. The programme has moved beyond simply sharing agencies' plans to fully combining their investments. By the end of fiscal year 2020, 3DEP-quality data were available or in progress for about 78 percent of the nation — but finding partners and funding in the western United States remained a challenge to finishing by 2023.

Why a unified approach

Buying data together benefits federal partners and taxpayers:

• lower unit costs, by pooling money and through the economies of larger projects;
• access to qualified, experienced mapping firms under contract;
• more consistent data from standard specifications and larger project areas;
• the chance to "buy up" to higher-quality data for special uses, and to receive 3DEP cost-share funding for lidar;
• USGS infrastructure to issue and manage contracts and to inspect, accept and distribute point clouds and derived products — so agencies need not duplicate it;
• more state, local, tribal and other partnerships, thanks to advance planning and a stable federal budget;
• data that are public, for countless other uses.

The best-practices checklist

Federal agencies are asked to:

• Sign the 3DEP governance memorandum of understanding.
• Assign representatives to the 3DEP Executive Forum and Working Group.
• Acquire data through the 3DEP acquisition process, and take part in multiyear planning.
• Adopt an agency policy of working within the unified federal 3DEP plan for acquiring and sharing data.
• Link regional and field offices into 3DEP and its acquisition processes.
• Help improve the acquisition process.
• When buying data outside 3DEP, make sure it meets the 3DEP specification, can be shared publicly (unlicensed) and is contributed to the national holdings.
• Take part in 3DEP budget initiatives and set up a 3DEP budget line.
• Report 3DEP investments to the budget crosscut (nine participating agencies).
• Promote 3DEP to the agency's constituents.
• Help assess and adopt new technologies.
• Encourage or require that federal grants used for elevation data produce data to 3DEP standards, contributed to the national holdings.
• Take part in the 3D Nation Elevation Requirements and Benefits Study and other studies of needs for future generations of 3DEP.

More practices are expected as the effort matures.

What comes next

Demand is growing for higher quality, repeat coverage and new products; the 3D Nation study is documenting these needs to design the next generation of 3DEP. Once complete, nationwide coverage will be a baseline for detecting and monitoring change — its value growing with use and with each repeat survey.

Sources

• Lukas, V., and Baez, V., 2021, 3D Elevation Program — Federal best practices: U.S. Geological Survey Fact Sheet 2020–3062. https://doi.org/10.3133/fs20203062
• The fact sheet cites Dewberry (2012), National Enhanced Elevation Assessment. It names the "National Geospatial Advisory Council"; the body is the National Geospatial Advisory Committee.
• The figure and the checklist are taken from the fact sheet's PDF.
• Rewritten in hubnx's own words.