2019 Eastern Iowa Topographic Lidar Validation – USGS Field Survey Data

Publication Date

2024-06-07

Start Date

2020-10-25

End Date

2020-10-31

Irwin, J.R., Danielson, J.J., Robbins, T.J., Kropuenske,T.J., Sampath, A., Kim, M., and Park, S., 2024, 2019 Eastern Iowa Topographic Lidar Validation – USGS Field Survey Data: U.S. Geological Survey, https://doi.org/10.5066/P9DI0G64.

Airborne topographic lidar can provide high-quality topographic information over large areas. Lidar is an active remote sensing technology that employs laser ranging in the near-infrared (1064 nm) spectral wavelength to provide three-dimensional (3D) point information for objects, including the Earth’s ground surface, vegetation, and infrastructure. The USGS 3D Elevation Program (3DEP) is a program managed by the National Geospatial Program that was developed to respond to the demand for high-quality topographic data and 3D information for natural features and infrastructure throughout the nation. 3DEP seeks to systematically acquire airborne topographic lidar for the conterminous U.S., Hawaii, and the U.S. territories to develop a nationwide baseline of consistent high-resolution topographic elevation data. A series of field accuracy assessment surveys, using conventional surveying methods combined with ground based lidar (GBL), were conducted at test sites in Cedar Falls, Cedar Rapids, Coralville, Davenport, and Iowa City, Iowa as well as Hampton and Moline, Illinois to evaluate the 3D absolute and relative accuracy of the airborne topographic lidar data collected using wide area mapping lidar systems. Airborne lidar data accuracy is most commonly expressed in terms of the vertical error (RMSEz) of the Digital Elevation Model (DEM) generated from the lidar points that are classified as ground, 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 more accurate than the airborne lidar data, such as point data collected from survey grade GNSS, total station, and GBL instruments. The survey data and unclassified GBL point clouds will be used to spatially assess the horizontal and vertical accuracy of the Eastern Iowa airborne topographic lidar data that were collected for 3DEP. This research will help 3DEP determine if these wide area mapping sensors meet current and future 3DEP topographic lidar collection requirements, as well as further research on methods to assess the 3D accuracy of point cloud data. For more information on 3DEP collection requirements, please see the latest version of the USGS Lidar Base Specification (https://www.usgs.gov/core-science-systems/ngp/ss/lidar-base-specification-online).

• Earth Resources Observation and Science Center (EROS)
• USGS Data Release Products