Izvorni znanstveni članak
Accuracy Assessment of Digital Terrain Models of Lowland Pedunculate Oak Forests Derived from Airborne Laser Scanning and Photogrammetry
Ivan Balenović
orcid.org/0000-0001-7422-753X
; Division for Forest Management and Forestry Economics Croatian Forest Research Institute Trnjanska cesta 35 10 000 Zagreb CROATIA
Mateo Gašparović
; Chair of Photogrammetry and Remote Sensing Faculty of Geodesy, University of Zagreb Kačićeva 26 10 000 Zagreb CROATIA
Anita Simic Milas
; School of Earth, Environment and Society Bowling Green State University 190 Overman Hall Bowling Green, OH USA
Alen Berta
; Department of Natural Resources Management Oikon Ltd. Institute of Applied Ecology Trg senjskih uskoka 1–2 10 000 Zagreb CROATIA
Ante Seletković
; Department of Forest Inventory and Management Faculty of Forestry University of Zagreb Svetošimunska 25 10 000 Zagreb CROATIA
Sažetak
Digital terrain models (DTMs) present important data source for different applications in environmental disciplines including forestry. At regional level, DTMs are commonly created using airborne digital photogrammetry or airborne laser scanning (ALS) technology. This study aims to evaluate the vertical accuracy of DTMs of different spatial resolutions derived from high-density ALS data and existing photogrammetric (PHM) data in the dense lowland even-aged pedunculate oak forests located in the Pokupsko basin in Central Croatia. As expected, the assessment of DTMs’ vertical accuracy using 22 ground checkpoints shows higher accuracy for ALS-derived than for PHM-derived DTMs. Concerning the different resolutions of ALS-derived (0.5 m, 1 m, 2 m, 5 m) and PHM-derived DTMs (0.5 m, 1 m, 2 m, 5 m, 8 m) compared in this research, the ALS-derived DTM with the finest resolution of 0.5 m shows the highest accuracy. The root mean square error (RMSE) and mean error (ME) values for ALS-derived DTMs range from 0.14 m to 0.15 m and from 0.09 to 0.12 m, respectively, and the values decrease with decreasing spatial resolution. For the PHM-derived DTMs, the RMSE and ME values are almost identical regardless of resolution and they are 0.35 m and 0.17 m, respectively. The findings suggest that the 8 m spatial resolution is optimal for a given photogrammetric data, and no finer than 8 m spatial resolution is required. This research also reveals that the national digital photogrammetric data in the study area contain certain errors (outliers) specific to the terrain type, which could considerably affect the DTM accuracy. Thus, preliminary evaluation of photogrammetric data should be done to eliminate possible outliers prior to the DTM generation in lowland forests with flat terrain. In the absence of ALS data, the finding in this research could be of interests to countries, which still rely on similar photogrammetric data for DTM generation.
Ključne riječi
DTM; ALS; LiDAR; stereo-photogrammetry; aerial images; even-aged forest stands; Central Croatia
Hrčak ID:
193559
URI
Datum izdavanja:
26.1.2018.
Posjeta: 1.518 *