Skip to main content
U.S. flag

An official website of the United States government

Lidar point density analysis: implications for identifying water bodies

December 9, 2014

Most airborne topographic light detection and ranging (lidar) systems operate within the near-infrared spectrum. Laser pulses from these systems frequently are absorbed by water and therefore do not generate reflected returns on water bodies in the resulting void regions within the lidar point cloud. Thus, an analysis of lidar voids has implications for identifying water bodies. Data analysis techniques to detect reduced lidar return densities were evaluated for test sites in Blackhawk County, Iowa, and Beltrami County, Minnesota, to delineate contiguous areas that have few or no lidar returns. Results from this study indicated a 5-meter radius moving window with fewer than 23 returns (28 percent of the moving window) was sufficient for delineating void regions. Techniques to provide elevation values for void regions to flatten water features and to force channel flow in the downstream direction also are presented.

Publication Year 2014
Title Lidar point density analysis: implications for identifying water bodies
DOI 10.3133/sir20145191
Authors Bruce B. Worstell, Sandra K. Poppenga, Gayla A. Evans, Sandra Prince
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2014-5191
Index ID sir20145191
Record Source USGS Publications Warehouse
USGS Organization Earth Resources Observation and Science (EROS) Center