Potomac River Topobathymetric Lidar Validation Survey Data

Publication Date

2020-04-23

Start Date

2019-10-18

End Date

2019-10-26

Irwin, J.R., Danielson, J.J., Kim, M., Young, J.A., Barlow, R., Thatcher, C., and Park, S., 2020, Potomac River Topobathymetric Lidar Validation Survey Data: U.S. Geological Survey data release, https://doi.org/10.5066/P9T291DH.

Airborne lidar can provide high-quality topographic and bathymetric information over large areas. Lidar is an active remote sensing technology that employs laser ranging in near-infrared and green spectral wavelengths to provide three-dimensional (3D) point information for objects, including Earth’s surface, submerged topography, vegetation, and infrastructure. USGS 3DEP seeks to acquire and evaluate topobathymetric lidar over select pilot areas within the conterminous U.S. Detailed knowledge of integrated river system topography and bathymetry is essential for key science applications such as inundation mapping, habitat characterization, and fluvial geomorphology. A series of field accuracy assessment surveys, using conventional surveying methods and GBL were conducted at test sites along the Potomac and Shenandoah Rivers in Maryland, Virginia, and West Virginia to evaluate the 3D absolute and relative accuracy of airborne topobathymetric lidar. Airborne lidar data accuracy is most commonly expressed in terms of the vertical error (RMSEz) of the Digital Elevation Model (DEM) produced from the lidar points that are classified as ground points or submerged topography, with little or no regard to the horizontal accuracy of the point cloud. High accuracy 3D point data are necessary to estimate the 3D accuracy of airborne lidar data. This requires validation data that are three times more accurate than the airborne lidar data, such as point data collected from survey grade GNSS, total station, and GBL instruments. The survey data will be used to spatially assess the horizontal and vertical accuracy of the Potomac River airborne topobathymetric lidar data the was coincidentally colledted for 3DEP, along with analyzing plane to plane offsets between various infrastructure roof features. This research will help 3DEP work toward operationalizing topobathymetric lidar by providing recommendations regarding topobathy lidar sensor performance and suitable site conditions for potential river acquisition surveys.

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