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2026 Vol.26, Issue 2 Preview Page

Research Article

The Effects of UAV-LiDAR Ground-point Density and Grid Resolution on DEM Accuracy

UAV-LiDAR 지면점 밀도와 공간 해상도가 DEM 정확도에 미치는 영향

홍일영1† · 김준석2

Ilyoung Hong1† · Juneseok Kim2

1남서울대학교 드론공간정보공학과 부교수
2남서울대학교 드론공간정보공학과 겸임교수
1Associate Professor, Department of Drone & GIS Engineering, Namseoul University
2Adjunct Professor, Department of Drone & GIS Engineering, Namseoul University
31 August 2026. pp. 15~26
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Abstract
UAV-LiDAR enables the rapid acquisition of high-density point clouds and is widely used for producing precise digital elevation models (DEMs), but it also has the drawback that storage and processing burdens increase as the volume of point cloud data grows. This study applied the experimental framework of Liu et al. (2007), originally developed for airborne LiDAR, to high-density UAV-LiDAR data to examine the effect of point cloud reduction on DEM accuracy. Ground points from the Anseongcheon Myeongdang Bridge area were divided into training data (90%) and check points (10%), and the training data were reduced in nine steps from 100% to 0.1% to generate DEMs at four grid resolutions (0.10–1.00 m), with accuracy evaluated by RMSE. When 25% or more of the training data was retained, the change in RMSE was small; RMSE was 4.3–5.5 cm when 5–10% was retained, and RMSE increased sharply below 1%. This study confirmed that, under low-density conditions, the lack of ground points affects accuracy more than grid size, suggesting that securing a minimum ground-point density should be prioritized over adjusting grid resolution when reducing UAV-LiDAR point clouds.
Keywords
UAV-LiDAR
Ground-point density
Digital Elevation Model (DEM)
Grid resolution
Accuracy assessment
UAV-LiDAR는 고밀도 점군을 빠르게 취득할 수 있어 정밀 DEM 제작에 널리 활용되지만, 점군 데이터양이 많아질수록 저장·처리 부담이 커진다는 단점도 있다. 본 연구는 Liu et al.(2007)의 항공 LiDAR용 실험설계를 고밀도 UAV-LiDAR 자료에 적용해 점군 감축이 DEM 정확도에 미치는 영향을 검토하였다. 안성천 명당교 일대 지면점을 훈련자료 90%와 검증점 10%로 분리하고, 훈련자료를 100~0.1%까지 9단계로 축소해 0.10~1.00m 해상도의 DEM을 생성한 뒤 RMSE로 정확도를 평가하였다. 훈련자료 25% 이상에서는 RMSE 변화가 작았고, 5~10% 유지 시 RMSE는 4.3~5.5cm였으며, 1% 이하에서는 RMSE가 급격히 증가하였다. 본 연구는 저밀도 조건에서 격자 크기보다 지면점 부족이 정확도에 더 큰 영향을 준다는 것을 확인하였으며, UAV-LiDAR 점군 감축 시 해상도 조정보다 최소 지면점 밀도 확보를 우선해야 함을 보여준다.
키워드
UAV-LiDAR
지면점 밀도
수치표고모델(DEM)
공간 해상도
정확도 평가
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Information
  • Publisher :The Korean Cartographic Association
  • Publisher(Ko) :한국지도학회
  • Journal Title :Journal of the Korean Cartographic Association
  • Journal Title(Ko) :한국지도학회지
  • Volume : 26
  • No :2
  • Pages :15~26
  • DOI :https://doi.org/10.16879/jkca.2026.26.2.015
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