U.S. Geological Survey (USGS) scientists completed a multidisciplinary data collection effort during the week of October 21-25, 2019, using new technologies to map and validate bathymetry over a large stretch of the non-tidal Potomac River. The work was initiated as an effort to validate commercially-acquired topobathymetric light detection and ranging (lidar) data funded through a partnership between the USGS and the Interstate Commission on the Potomac River Basin (ICPRB). The goal was to compare airborne lidar data to bathymetric data collected through more traditional means (boat-based sonar, wading Real Time Kinematic Global Navigational Satellite System (RTK-GNSS) surveys) and through unmanned aerial systems (UAS). In addition to accurately measuring river bottom elevations with GNSS and sonar, remote sensing imagery was collected with optical, multispectral, thermal, and ground-based lidar (GBL) sensors to test new technologies. The bathymetric lidar data, once delivered, will be used for hydrodynamic and water supply risk modeling, aquatic habitat assessments, and to test inland bathymetry mapping capabilities for inclusion in the USGS National Geospatial Program (NGP) 3D Elevation Program (3DEP). The data contained within this particular release are comprised of conventional survey (i.e. total station and GNSS) and GBL data.

U.S. Geological Survey (USGS) scientists conducted field data collection efforts during the week of September 25 – 29, 2017, using a combination of conventional surveying technologies, for a large stretch of the Kootenai River near Bonners Ferry, Idaho. The work was initiated as an effort to validate commercially acquired topobathymetric light detection and ranging (lidar) data. The goal was to compare the airborne lidar data to topographic and bathymetric data collected through more traditional means (e.g. waded Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS) surveys). The validated topobathymetric lidar data will be used for hydrologic modeling, assessment and restoration of aquatic habitat, sediment transport modeling, and to assess inland bathymetry mapping capabilities for inclusion in the USGS National Geospatial Program (NGP) 3D Elevation Program (3DEP).

U.S. Geological Survey (USGS) scientists conducted field data collection efforts between August 17th and 28th, 2020 over a large stretch of the Niobrara River in Nebraska using high accuracy surveying technologies. The work was initiated as an effort to validate commercially acquired topobathymetric light detection and ranging (lidar) data. The goal was to compare and validate the airborne lidar data to topographic, bathymetric, structural, and infrastructural data collected through more traditional means (e.g. Global Navigational Satellite System (GNSS) surveying). The airborne topobathymetric lidar data will be used for characterization of endangered species aquatic habitat, improving the understanding of fluvial geomorphic features, sediment transport modeling, and 2D/3D hydrologic and hydraulic modeling. The impacts of the spring 2019 flood and resulting Spencer Dam failure will be further assessed and monitored using the lidar data along with testing inland topobathymetric lidar mapping capabilities for inclusion in the USGS National Geospatial Program (NGP) 3D Elevation Program (3DEP).

U.S. Geological Survey (USGS) scientists conducted field data collection efforts between July 19th and 31st, 2021 over a large stretch of the McKenzie River in Oregon using high accuracy surveying technologies. The work was initiated as an effort to validate commercially acquired topobathymetric light detection and ranging (lidar) data that was collected coincidentally between July 26th and 30th, 2021 for the USGS 3D Elevation Program (3DEP). The goal was to compare and validate the airborne lidar data to topographic, bathymetric, structural, and infrastructural data collected through more traditional means (e.g., Global Navigational Satellite System (GNSS) surveying). Evaluating these data will provide valuable information on the performance of inland topobathymetric lidar mapping capabilities and their potential for use and inclusion in the USGS National Geospatial Program 3D Elevation Program. The airborne topobathymetric lidar data will be used for developing reliable hydraulic models, which can be used to model potential flood inundation and analysis for other potential hazards such as landslides. The bathymetric lidar data will also be used for characterization of endangered species aquatic habitat, including that of salmon and steelhead trout species. Furthermore, a large portion of the McKenzie River corridor that was mapped by the airborne topobathymetric lidar was impacted by the Holiday Farm Fire that burned over 170,000 acres during September of 2020 and the airborne data will be used to support post-fire geomorphic change detection.

U.S. Geological Survey (USGS) scientists conducted field data collection efforts between September 30th and October 9th, 2021 over a large stretch of the Potomac River in Maryland and West Virginia using high accuracy surveying technologies. The work was initiated as an effort to validate commercially acquired topobathymetric light detection and ranging (lidar) data that was collected coincidentally between October 3 - 5, 2021 for the USGS 3D Elevation Program (3DEP). The goal was to compare and validate the airborne lidar data to topographic, bathymetric, structural, and infrastructural data collected through more traditional means (e.g., Global Navigational Satellite System (GNSS) surveying). Evaluating these data will provide valuable information on the performance of inland topobathymetric lidar mapping capabilities and their potential for use and inclusion in the USGS National Geospatial Program 3D Elevation Program. The primary uses for the airborne topobathymetric lidar data will be hydrodynamic and water supply risk modeling and aquatic habitat assessments. The data contained within this particular release are comprised of conventional survey (i.e. total station and GNSS) and ground based lidar data.

U.S. Geological Survey (USGS) scientists conducted field data collection efforts during the weeks of September 9-13 and November 18-22, 2019, using a combination of technologies to map and validate topography, vegetation, and features in two areas of interest (AOI's) in north central Colorado. The western AOI included land managed by the Bureau of Land Management and the U.S. Forest Service. The eastern AOI included agricultural and urban areas. The work was initiated as an effort to test and evaluate the Leica Geosystems CountryMapper* sensor. The CountryMapper is a hybrid sensor that collects imagery and light detection and ranging (lidar) data simultaneously. The CountryMapper has the potential to collect data that satisfies both USGS National Geospatial Program (NGP) 3D Elevation Program (3DEP) and U.S. Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) requirements in a single collection. Real Time Kinematic Global Navigational Satellite System (RTK-GNSS), total station, ground based lidar (GBL), Unmanned Aerial System (UAS) lidar, and UAS imagery data were collected to compare to the data collected by the CountryMapper. * Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

U.S. Geological Survey (USGS) scientists conducted field data collection efforts during the weeks of September 9-13 and November 18-22, 2019, using a combination of technologies to map and validate topography, vegetation, and features in two areas of interest (AOI's) in north central Colorado. The western AOI included land managed by the Bureau of Land Management and the U.S. Forest Service. The eastern AOI included agricultural and urban areas. The work was initiated as an effort to test and evaluate the Leica Geosystems CountryMapper* sensor. The CountryMapper is a hybrid sensor that collects imagery and light detection and ranging (lidar) data simultaneously. The CountryMapper has the potential to collect data that satisfies both USGS National Geospatial Program (NGP) 3D Elevation Program (3DEP) and U.S. Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) requirements in a single collection. Real Time Kinematic Global Navigational Satellite System (RTK-GNSS), total station, ground based lidar (GBL), Unmanned Aerial System (UAS) lidar, and UAS imagery data were collected to compare to the data collected by the CountryMapper. * Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

A permeable rock-fill causeway was constructed across Great Salt Lake between 1957–1959, dividing the lake into North and South Arms. Several open channels have been constructed to connect the two arms of the lake, with the most recent, informally named the New Breach, being completed in 2016. A berm across the New Breach restricts flow between the North and South Arms and was originally built to 4,183 feet above the National Geodetic Vertical Datum of 1929 (NGVD29, in accordance with historical elevation records at Great Salt Lake). However, due to increasing salinity and low water-surface elevation and volume in the South Arm, water managers raised the berm in July 2022 to 4,187 feet above NGVD29 and again in February 2023 to 4,192 feet above NGVD29 to capture freshwater in the South Arm and maximize dilution of salinity. Elevation data were collected through the breach and adjacent areas after the berm was raised in 2023 to monitor changes in berm geometry and surrounding channel bathymetry. A seamless topobathymetric digital elevation model was assimilated using drone-derived topography and acoustic doppler current profiler (ADCP) bathymetry. Surface and shallow topography were surveyed by drone photogrammetry on October 19, 2023 and August 14, 2024. A handheld real-time kinematic (RTK) global navigation satellite system (GNSS) receiver, consisting of a base-station receiver referenced over a known point and elevation and a mobile-station receiver, collected single-point elevation data in the survey area including across the partially submerged berm. The RTK data provides an independent measure of elevation to assess the photogrammetric digital elevation model (DEM) for horizontal or vertical error and to build a simple regression for calibrating the submerged topography. This regression for submerged topography is limited to shallow, clear water in parts of the breach with laminar flow where an RTK measurement could be safely made. Because the berm was partially eroded and submerged during surveying activities, only the drone-derived DEM could show the character of erosion in the berm and provide accurate estimates of topography. The management berm eroded from the as-built elevation of 4,192 feet to approximately 4,187 feet, at its lowest point across the breach, between its construction on February 10, 2023, and October 19, 2023. The vertical error subaerial topography is less than one centimeter (cm); for submerged regions across the berm only, the median error estimate is 3.01 cm.

The U.S. Army Corps of Engineers–-Little Rock District (SWL) Civil Works program has a mission to maintain cohesion between physical and naturally developed environments. Evaluation of shoreline stability and adjacent development of a harbor along the McClellan-Kerr Arkansas River Navigation System at River Mile 202.6 is essential in establishing a baseline for potential impacts and future monitoring of the proposed harbor. A combination of multibeam sonar and high-resolution, low-altitude aerial light detection and ranging (lidar) data were used to provide data and analysis needed for as-built information and future monitoring of river shoreline and floodplain management and maintenance. In October 2021, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, completed high-resolution bathymetric (underwater elevation) and topographic surveys of the Arkansas River and a quarry at the proposed slack water harbor near Dardanelle, Arkansas. Bathymetric data were collected using a high-resolution multibeam echosounder mapping system (MBMS), which consists of a multibeam echosounder (MBES) and an inertial navigation system (INS) mounted on a marine survey vessel. Data were collected as the vessel traversed the river and quarry along overlapping survey lines distributed throughout the areas. Data collection software integrated and stored the depth data from the MBES and the horizontal and vertical position and attitude data of the vessel from the INS in real time. Data processing required computer software to extract bathymetry data from the raw data files and to summarize and map the information. Topographic data were collected as a lidar point cloud (LPC) using an Unmanned Aircraft System (UAS) with a YellowScan Vx20-100 lidar payload, which consists of the lidar scanner and an INS. The LPC data were collected as the UAS followed two perpendicular transects orientations (north-south and east-west) on separate flights. The LPC was corrected using a post-processed kinematic (PPK) solution with a Trimble R8s base station, and ground control points (GCPs) surveyed using Propeller AeroPoint smart targets which were PPK corrected to a nearby continuously operated reference station (CORS) tower. The LPC was attributed to the American Society for Photogrammetry and Remote Sensing (ASPRS) point classification standards. The LPC was colorized from a UAS-collected red-green-blue (RGB) orthoimage collected using a Ricoh GR camera. The processed bathymetric datasets and the UAS lidar dataset are provided in the ASPRS LAS format with associated metadata files in the zipped archive named SlackWaterHarbor_DardanelleAR_2021-10_data.zip. The LAS format is a standardized binary format for storing 3-dimensional point cloud data and point attributes along with header information and variable length records specific to the data. Data points are stored as a 3-dimensional data cloud as a series of x (longitude), y (latitude) and z (elevation) points. Please refer to http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html for additional information. Topographic data outside of the area collected by the UAS were extracted from aerial lidar data collected in 2014, publicly available from the USGS National Elevation Dataset (NED) at https://prd-tnm.s3.amazonaws.com/LidarExplorer/index.html#/. The two bathymetric datasets, the ground points from the UAS lidar data thinned to a 1.64-foot (0.5-meter) resolution, and the public lidar data were combined to create a multisource point cloud of the ground in the proposed harbor area and surroundings. The multisource point cloud dataset is provided in ESRI Shapefile format (ESRI, 2021) with an attribute table and metadata in the zipped archive named SlackWaterHarbor_DardanelleAR_2021-10_Multisource_data.zip. Attribute/column labels of this table are described in the "Entity and attribute" section of the associated metadata file. The multisource point

This dataset provides a modified version of the previously published Lake Powell topobathymetric digital elevation model (TBDEM; Poppenga and others, 2020). The original TBDEM is comprised of four source datasets: (1) a 2017 1-meter multibeam bathymetric survey; (2) a 2018 topographic light detection and ranging (lidar) derived digital elevation model (DEM); (3) a historical topographic DEM that was interpolated from contours maps created in 1947 and 1959; and (4) interpolated topography where gaps existed in the bathymetric and lidar data or where historical data were not suitable (Poppenga and others, 2020). For this data release, two corrections were made to the TBDEM to address errors associated with the historic DEM and interpolated topography across data gaps: (1) filled in selected gaps of the TBDEM dataset that were corrected with the historic DEM but have since been filled with sediment; and (2) spliced alternate topographic data sources instead of the hydro-flattened elevations in the river channel upstream of the Colorado and San Juan River deltas. The modified TBDEM was generated in a horizontal projection of UTM Zone 12N, North American Datum of 1983, referenced to the North American Vertical Datum 1988 (NAVD88), Geoid 12b at a 1-meter horizontal resolution. The modified TBDEM and an updated spatial metadata shapefile detailing data sources used and modifications made to the TBDEM are included with this release.