Ground-return density and internal vertical differences in 1 m airborne lidar terrain models
Abstract
Airborne lidar surveys are typically planned based on overall pulse density, yet digital terrain models (DTMs) rely exclusively on returns classified as ground. Because complex terrain and vegetation limit actual ground returns, high nominal pulse density does not guarantee adequate ground-return density. This study investigates how reducing the density of available ground returns impacts the internal consistency of 1-meter DTMs across diverse landscapes. Using data from two USGS 3D Elevation Program acquisitions in Utah and Idaho, four distinct sites were analyzed. At each location, 10% of the ground returns were withheld as a control set. The remaining 90% established a high-density reference DTM. This baseline dataset was systematically reduced using a spatially balanced thinning method with target densities ranging from 4 down to 0.03125 points per square meter. New DTMs were then generated via linear TIN interpolation. Results demonstrate that internal elevation differences increase steadily as point density declines. At 1 point per square meter, the Root Mean Square Error (RMSE) varied drastically by topography. It ranged from 0.010 meters on low-relief plains to 0.084 meters on steep escarpments. Errors peaked on steep slopes and in areas with dense non-ground features. Furthermore, purely random thinning increased the RMSE by 13% to 120% compared to spatially balanced thinning, proving that the spatial arrangement of points is as critical as the overall point count. Ultimately, these findings highlight DTM interpolation sensitivity and provide practical insights for evaluating surface reliability based on realized ground-return density.
Keywords
- Airborne laser scanning
- Ground-return density
- Digital terrain model
- Density reduction
- Internal vertical difference
Ethical Statement
In the study, the author declares that there is no violation of research and publication ethics.
Thanks
The author acknowledges the U.S. Geological Survey for providing the 3D Elevation Program point-cloud data used in this study. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
References
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Details
Primary Language
English
Subjects
Computational Modelling and Simulation in Earth Sciences
Journal Section
Research Article
Authors
Publication Date
September 30, 2026
Submission Date
August 5, 2026
Acceptance Date
September 3, 2026
Published in Issue
Year 2026 Volume: 8 Number: 2
APA
Kesikoğlu, M. H. (2026). Ground-return density and internal vertical differences in 1 m airborne lidar terrain models. Turkish Journal of Applied Geoinformation Sciences, 8(2), 93-105. https://doi.org/10.53030/tjags.2011590
AMA
1.Kesikoğlu MH. Ground-return density and internal vertical differences in 1 m airborne lidar terrain models. Turk. J. Appl. Geoinf. Sci. 2026;8(2):93-105. doi:10.53030/tjags.2011590
Chicago
Kesikoğlu, Mustafa Hayri. 2026. “Ground-Return Density and Internal Vertical Differences in 1 M Airborne Lidar Terrain Models”. Turkish Journal of Applied Geoinformation Sciences 8 (2): 93-105. https://doi.org/10.53030/tjags.2011590.
EndNote
Kesikoğlu MH (September 1, 2026) Ground-return density and internal vertical differences in 1 m airborne lidar terrain models. Turkish Journal of Applied Geoinformation Sciences 8 2 93–105.
IEEE
[1]M. H. Kesikoğlu, “Ground-return density and internal vertical differences in 1 m airborne lidar terrain models”, Turk. J. Appl. Geoinf. Sci., vol. 8, no. 2, pp. 93–105, Sept. 2026, doi: 10.53030/tjags.2011590.
ISNAD
Kesikoğlu, Mustafa Hayri. “Ground-Return Density and Internal Vertical Differences in 1 M Airborne Lidar Terrain Models”. Turkish Journal of Applied Geoinformation Sciences 8/2 (September 1, 2026): 93-105. https://doi.org/10.53030/tjags.2011590.
JAMA
1.Kesikoğlu MH. Ground-return density and internal vertical differences in 1 m airborne lidar terrain models. Turk. J. Appl. Geoinf. Sci. 2026;8:93–105.
MLA
Kesikoğlu, Mustafa Hayri. “Ground-Return Density and Internal Vertical Differences in 1 M Airborne Lidar Terrain Models”. Turkish Journal of Applied Geoinformation Sciences, vol. 8, no. 2, Sept. 2026, pp. 93-105, doi:10.53030/tjags.2011590.
Vancouver
1.Mustafa Hayri Kesikoğlu. Ground-return density and internal vertical differences in 1 m airborne lidar terrain models. Turk. J. Appl. Geoinf. Sci. 2026 Sep. 1;8(2):93-105. doi:10.53030/tjags.2011590