Topographic Lidar Data Collection Plan

Multiple topographic lidar data collection scenarios (table 1) were evaluated for the ensuing 3DEP plan. The primary factors considered when evaluating each alternative included an analysis of user needs identified in the 3D Nation Study (NOAA, 2022), current data collection and cost trends, and projected program costs of future investments. The data collection strategies were reviewed in multiple industry and user community forums, and a consensus resulted in the recommendation to adopt scenario 3 to collect quality level (QL) 1 or QL2 (table 2) topographic lidar for the conterminous United States in 5 years, and Alaska, Hawaii, and U.S. territories in 8 years.

Scenario 3 provides the flexibility that partner organizations are asking for and allows for data collections that most cost-effectively meet the needs of users. The 3D Nation Study results (NOAA, 2022) based on mission critical activity (MCA) frequency counts by quality level were used to calculate cost and benefits for the mixed quality program scenario. The mix used for planning estimates is about 60 percent QL1 and 40 percent QL2. Much of the Western United States and coastal areas in the Eastern United States were identified as candidates for QL1 data collections. Although these areas were identified in the 3D Nation Study for QL1 data collections, specific partner requirements will likely determine the acquisition quality for each area as it is identified for a collection project. The acquisition approach would be similar to the 3DEP baseline partnership model with some notable changes (table 3) in the acquisition method and the way USGS provides funding by quality level. The USGS aims to participate in more frequent acquisitions in areas where substantial changes to the landscape have occurred. All data would be collected according to the most current USGS Lidar Base Specification (U.S. Geological Survey, 2022) and in accordance with the Geospatial Data Act, section F of the FAA Reauthorization Act (P.L. 115–254, 132 Stat. 3413) standards.

Elevation Requirements and Benefits

The 3D Nation Study identified $13.5 billion in annual benefits across 1,352 mission critical requirements for 45 Federal agencies, 50 States and Washington, D.C., 99 local and 8 Tribal governments, 34 private companies, 5 territories, and 24 other organizations (NOAA, 2022). Topographic and inland topobathymetric lidar benefits, if fully realized, represent $10.8 billion out of a total $13.5 billion documented for all data types and geographies. The comprehensive study assessed a wide range of requirements for inland, nearshore, and offshore topographic and bathymetric elevation data. In the study, participants identified MCAs and potential dollar benefits that could be realized if their data needs could be met. Some of the most important requirements are highlighted below and in the topobathymetric data section. These requirements represent a small portion of the content addressed in the study. 3D Nation Study respondents identified needs for higher quality data (table 4) that are more frequently collected (table 5) than the current baseline 3DEP data. Lidar data quality and collection rates are the two requirements that most directly influenced planning for the next generation of 3DEP data collection activities. When study respondents were asked to rank the importance of update frequency, vertical accuracy, and geographic coverage, update frequency was chosen as the most important at 74 percent, followed by vertical accuracy at 15 percent.

The 3D Nation Study participants identified data requirements (required or highly desired) to support MCAs that included the following:

Topographic Lidar Data Collection Trends

Topographic lidar data collection costs (fig. 3) have been declining since USGS began detailed tracking of lidar acquisition projects in 2012. QL2 topographic lidar data collection costs have leveled off and are projected to remain at or near $200 per square mile, assuming no major shifts in technology or other related costs, such as fuel and labor. QL1 data collection costs have been declining at a faster rate, and future costs are projected at $340 per square mile. The QL1 cost decline in recent years (not leveled off) indicates that further cost declines are possible. While data acquisition costs have declined, other costs for processing data and creating derived products and services have increased due to the increased data density.

The reductions in 3DEP data collection costs for QL1 and QL2 topographic lidar have been mirrored by the trend toward QL1 data collection projects (fig. 4). In fiscal year 2022, the number of square miles acquired at QL1 exceeded the number of square miles acquired at QL2. The trend indicates that QL2 data collections would be almost entirely replaced by QL1 (or better) collections in the next few years.

Inland Topobathymetric Lidar Data Collection Strategy

Federal agencies, including the NOAA, U.S. Army Corps of Engineers (USACE), and USGS collect lidar, sonar, image-derived bathymetry, and other remotely sensed data to meet their bathymetric data needs. These same techniques can be used to acquire bathymetry for inland water bodies, depending on the environmental conditions. The USACE Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) is leading a community-driven effort to establish a specification for topobathymetric lidar. The USGS Lidar Base specification (U.S. Geological Survey, 2022) for topographic lidar is being used as the starting point for this development effort. The American Society for Photogrammetry and Remote Sensing (ASPRS) established a lidar bathymetry working group led by USACE and USGS staff to help complete the draft specification and to vet it through the ASPRS community. Through the process of validating several pilot topobathymetric lidar datasets, and research on accuracy and performance, the USGS Earth Resources Observation Science (EROS) Center has gained knowledge about the technology that has improved data validation techniques and has refined the collection requirements outlined in USGS task orders for topobathymetric lidar. These efforts are fundamental to developing a more systematic approach to acquiring and managing topobathymetric data.

Requirements for topobathymetric data were identified in the 3D Nation Study (NOAA, 2022) and at Federal inland bathymetry workshops held in 2019 and 2022. The 3D Nation Study identified $860 million in annual benefits for inland bathymetry that could be realized if all needs were met. Considering that the availability of inland topobathymetric data is limited, this is a substantial potential benefit. The 3D Nation Study documented requirements for inland bathymetry on 831 of the 1,352 (61 percent) identified MCAs, as well as a need to integrate bathymetry with topographic lidar collected for uplands to create seamless terrestrial elevation data. The detailed requirements for data types, quality, update frequency, and use are documented in the study report. These requirements are primary drivers for the research, development, and data collection projects for the next generation of 3DEP and 3DHP within the 3DNTM framework.

Inland bathymetry includes data collected on the bottoms of lakes, reservoirs, and rivers, which requires a mix of lidar and sonar, or other emerging technologies, such as image-derived bathymetry. The initial USGS 3DNTM plans for bathymetric mapping will focus mainly on inland rivers. 3DEP is leveraging the program’s experience with lidar technology to map bathymetry using topobathymetric (green laser) lidar. Topobathymetric lidar is most suitable for relatively clear, shallow water bodies with a bright bottom substrate, which are typically rivers in the context of inland water bodies. Mapping the entire river channel bathymetry plus the surrounding riverbanks is challenging, and usually requires a combination of technologies, such as topobathymetric lidar and multibeam sonar data collected from a boat. Lakes and reservoirs are typically mapped with sonar technology because deeper water bodies with dark bottoms are not suitable for topobathymetric lidar. Many rivers in the United States, particularly in the Midwest and eastern regions, are also unsuitable for current topobathymetric lidar technologies due to poor water clarity.

3DEP has been acquiring airborne topobathymetric lidar for inland river pilot projects through the USGS Geospatial Products and Service Contracts (GPSC). This lidar is typically collected to meet QL2 standards described in the Interagency Working Group on Ocean and Coastal Mapping (2018) National Coastal Mapping Strategy. The purpose of the pilot surveys is to test topobathymetric lidar sensors in a variety of rivers with different bottom types, water clarity, and depth to understand sensor performance and to determine what environmental conditions are suitable for the technology. This information can be used in the future to identify inland rivers where topobathymetric lidar would be effective for mapping bathymetry.

The 3DEP topobathymetric elevation data acquisition strategy is driven by the requirements of USGS science and Federal, State, Tribal, and local partners, and where the aquatic environmental conditions are favorable for topobathymetric lidar. As lidar sensors continue to improve and emerging bathymetric mapping technologies become operational, 3DEP aims to continue to evaluate the program plans and, if possible, expand the types and locations of water bodies that are included. Additional partner investments could accelerate the availability of integrated topobathymetric DEMs for the Nation. For example, the NOAA is currently acquiring topobathymetric lidar for several inland rivers to support flood forecasting. The 3DEP plan currently does not include contracting for sonar or acquiring new topobathymetric data for lakes, which are typically mapped by others with boat-based sonar.

Other groups, including USACE, the Bureau of Reclamation, and the USGS Water Mission Area, are mapping selected rivers, lakes, and reservoirs with sonar and other technologies. The USGS 3DNTM aims to play a complementary role by helping to coordinate inland bathymetry mapping efforts among agencies. The 3DNTM plans involve bringing topographic lidar, topobathymetric lidar, sonar, and other bathymetry data sources together to create a continuous elevation surface that maps both terrestrial and submerged topography.

Coastal, nearshore, and offshore bathymetric mapping is led by NOAA’s Office of Coast Survey and National Geodetic Survey Remote Sensing Division and through the USACE JALBTCX. The JALBTCX National Coastal Mapping Program maps the coast of the United States (including the Great Lakes) on a recurring basis. These agencies work together to acquire and publish topographic and bathymetric elevation data in the coastal zone.

The USGS can leverage the work of the other agencies and contribute to the advancement of an inland topobathymetric component of 3DEP by

The USGS NGP aims to expand development in the four areas as outlined above and intends to assess the next steps for moving toward a more systematic national approach to acquire and facilitate inland bathymetry data. During the first 5 years, 3DEP will likely focus on coordinating with other Federal agencies to identify and access source data, developing an operational approach for producing topobathymetric DEMs, and determining the need for additional products such as bankfull or top of bank, depth, and thalweg.

3D Nation Ecosystem—Access to Community-Wide Data

3DEP data and products created from standardized topographic lidar and IfSAR data collections are currently (2025) managed within a single nationwide data repository managed by the USGS. In the next generation of the program, 3DEP would retain a partnership approach to collect authoritative data but would expand its facilitation and coordination role to integrate additional data resources under a federated big data governance model to support broader needs for 3D information. A new 3D Nation Ecosystem, in cooperation with NOAA as part of the 3D Nation concept and in partnership with other Federal agencies (fig. 5), could expand access to a broad range of partner data and information services allowing for a more flexible approach to meeting user needs. For example, direct data contributions and sharing of tools and software code among the 3DEP Working Group (refer to governance below) members would enable users to turn data into information and to compare and use datasets interchangeably. The 3D Nation Ecosystem concept would be more fully defined through the research program with an overarching goal to reduce duplication and make more elevation data readily available by connecting to other non-authoritative dataset resources. It is anticipated that the 3D Nation Ecosystem will initially be released as a small set of data (such as connecting to NOAA Digital Coast) and may expand over time with the goal to include data from States, Tribal, and other organizations.

Next-Generation 3DEP Research and Development Agenda

The next generation of 3DEP includes program objectives that require new data specifications, improved production throughput, and advanced capability to meet user needs. Each of the 10 research activities identified below is designed to produce an outcome that directly supports these 3DEP requirements. A detailed research plan is under development to address these needs. The research activities may be led by multiple USGS programs or by another partner Federal agency. Partnerships with the private sector, Tribes, universities, and States could advance key elements of the research agenda. Generally, the work will likely be coordinated by the USGS NGP unless another Federal agency is leading the effort. The 3DEP research objectives, which often include multiple components, include the following:

Most of the research activities have been initiated and may be periodically reviewed and refined as the next generation of 3DEP is implemented. Research will include continuous evaluations of new technologies and offer recommendations for operational changes. These may involve authoritative data streams or connected resources via the 3D Nation Ecosystem. Timelines (fig. 6) exist for each of the research actions that coincide with program deliverables planned through year 5 of the next generation of 3DEP.

Federal Roles and Responsibilities

The ongoing success of 3DEP depends on the active support of Federal agencies to fulfill the following roles and responsibilities:

State Roles and Responsibilities

The States are major partners and often lead statewide acquisition programs. The 3DEP planning approach is intended to encourage the expansion of state-level partnerships. State roles and structures continue to vary across the country. It is incumbent upon the Federal agencies to recognize this and accommodate the variation that exists. Characteristics of successful State partnerships include the following elements:

The 3DEP partnership approach addresses findings in the U.S. Government Accountability Office’s report GAO–13–94 on geospatial information coordination and reducing duplication (U.S. Government Accountability Office, 2012) and fulfills OMB’s requirements (Office of Management and Budget, 2013) for managing National Geospatial Data Assets through a unified and well-communicated process of coordination and partnerships.

Tribal Coordination

All Federally recognized Tribes would be notified about the next generation of 3DEP and invited to participate in the program. USGS has determined that the acquisition and publication of airborne lidar for Tribal lands requires Tribal notification to comply with the DOI Tribal consultation policy. USGS notifies Tribes before acquiring and publishing lidar data, and upon request, restricts public access to elevation data products for Tribal lands to respect the data sovereignty and privacy of Tribes. The restricted data are provided to the Tribe for their use if requested.

For lidar data collection efforts, Tribes are encouraged to submit proposals for matching Federal funding through the annual 3DEP Data Collaboration Announcement (DCA). The USGS has funded proposals led by Tribes over the years. The NGP network of National Map Liaisons can assist Tribes with questions about lidar data. The liaisons also attend meetings and conferences hosted by intertribal organizations to share information about 3DEP and other USGS programs and to build relationships with Tribes. Tribes are encouraged to reach out to their liaison to learn more about how to engage with the program.

Funding

3DEP was envisioned as a major data collection effort that would rely heavily on partners working together to fund data acquisition. This model has been highly successful. In addition to funding operations, including managing governance, partnerships, data acquisition and processing, and delivery of 3DEP products and services, the USGS funded 21 percent (while partners [including special appropriations] funded 79 percent) of the total data acquisition cost in fiscal years 2015 to 2023 (fig. 7) to collect data for the Nation (total funding, including program management, is shown in figure 8). Partners funded about 62% of the overall costs of the program. Substantial funding was provided by three Federal agencies—Natural Resources Conservation Service, Federal Emergency Management Agency (FEMA), and the USGS—and by States that participated in data collection projects. More than 350 Federal, State, and other partners have made contributions to 3DEP. In addition to partnership contributions, special appropriations such as supplemental funding for disasters have provided substantial support to data acquisition and operations.

Funding for 3DEP increased each fiscal year from 2015 to 2019 (fig. 8). These funding increases occurred as the program experienced early successes and partner investments grew. Initially, funding from USGS and partner agencies targeted the high-priority areas in the United States. As the program progressed, the remaining lower priority areas without coverage had fewer partnership opportunities, and funding began to decline. The funding declines can, in part, be attributed to Federal and State budget reductions during the COVID-19 pandemic. Although funding has been limited, the areas yet to be collected have significant benefit potential, particularly related to natural resource management, environmental assessments, and energy development. However, requirements and potential benefits do not always translate into funding for lidar when those activities support programs outside of the existing partnership circle. With a mission to provide consistent nationwide data for all areas, including socioeconomically vulnerable communities, the USGS will strive to expand partnership development efforts to attract other Federal and State agencies, NGOs, Tribal, and private sector partnerships in geographies where historical funding has been lacking.

Next-Generation 3DEP Funding Strategy

The next generation of 3DEP is designed to support the high-priority needs identified in the 3D Nation Study. The need to collect higher quality data on a 5-year collection cycle has a projected cost that is about 2.4 times the baseline data collection program. Like the original 3DEP Call for Action (Sugarbaker and others, 2014), it is assumed that funding growth will be incremental (fig. 9) until a level necessary to sustain the new data collection rates is achieved. Next-generation 3DEP planning assumes a continuing program where new collection cycles are initiated every 5 years to support business applications or repeat data collections are needed to assess change. This overall change in strategy and program scope requires that partnership investments increase to cover the projected cost. The community response to the next-generation 3DEP plan could directly affect the size and nature of the program moving forward.

The funding needs for the next generation of 3DEP may require new partnerships and increased commitments from the USGS and partner organizations. Federal programs and new legislation, such as the next generation of flood hazard and risk information from FEMA, the NOAA National Water Model (National Oceanic and Atmospheric Administration, 2016), NLPA, Inflation Reduction Act, USGS Earth Mapping Resources Initiative (Earth MRI), USDA Farm Production and Conservation Business Center (FPAC), USFS Geospatial Technology and Applications Center (GTAC) and various disaster recovery funds have made substantial contributions to 3DEP. States and Tribes have participated in 3DEP by jointly funding projects or directly contributing elevation data. 3DEP could continue to rely on these funding sources to meet future program needs.

The USGS, with assistance from partner organizations, will likely expand the education and outreach activities to reach new communities of interest. These may include the non-profit sectors (including charitable trusts), education research communities, private sectors, and other government institutions. Although the 3D Nation Study reached a broad community of users, new potential uses may emerge over the next few years. An outreach strategy will seek to reach these new data consumer communities. While the current USGS National Map liaison network may be a critical part of this strategy, additional resources and approaches may be needed to identify and reach new potential partners. A market research and outreach activity could assess new opportunities in the government, private, Tribal, and NGO communities and develop a strategy for engaging key organizations. New funding could be expanded into less traditional areas, such as broadband, precision agriculture, oil and gas, transportation, development, medical research, social services, and others.

Risk Management and 5-year Program Assessment

The next generation of 3DEP is an ambitious effort to increase data acquisition quality levels, collect data more frequently, shorten the production timeline, expand data collection to include topobathymetric lidar, and expand service offerings. The overall program management approach to provide a forum for quickly recognizing a changing technology landscape and new customer requirements could enable stability and short-term success. As in the past, the program would be managed for continuous improvement. However, a more comprehensive assessment of the program and progress toward these goals could occur about 5 years after the next generation of 3DEP is initiated. At 5 years, the research and development efforts in the areas of change detection methodologies, integrated topobathymetric and topographic data products, new data collection systems, and the 3D Nation Ecosystem are expected to provide insights on how to further advance the 3DEP. The 5-year assessment could provide a more formal program evaluation and substantial adjustments to the long-term goals.

The known program risks have been documented, and strategies have been developed to minimize risk exposure or to have a plan of action when risk cannot be mitigated. The management strategy, as outlined above, allows for the inevitable adjustments to counter these risks. Known risks associated with the 3DEP expansion include the following:

The core 3DEP strategies to manage these risks include the following: