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Assessment of forest structure using two UAV techniques: a comparison of airborne laser scanning and structure from motion (SfM) point clouds


Wallace, LO and Lucieer, A and Malenovsky, Z and Turner, D and Vopenka, Petr, Assessment of forest structure using two UAV techniques: a comparison of airborne laser scanning and structure from motion (SfM) point clouds, Forests, 7, (3) Article 62. ISSN 1999-4907 (2016) [Refereed Article]


Copyright Statement

Copyright 2016 The Authors Licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)

DOI: doi:10.3390/f7030062


This study investigates the potential of unmanned aerial vehicles (UAVs) to measure and monitor structural properties of forests. Two remote sensing techniques, airborne laser scanning (ALS) and structure from motion (SfM) were tested to capture three-dimensional structural information from a small multi-rotor UAV platform. A case study is presented through the analysis of data collected from a 30 50 m plot in a dry sclerophyll eucalypt forest with a spatially varying canopy cover. The study provides an insight into the capabilities of both technologies for assessing absolute terrain height, the horizontal and vertical distribution of forest canopy elements, and information related to individual trees. Results indicate that both techniques are capable of providing information that can be used to describe the terrain surface and canopy properties in areas of relatively low canopy closure. However, the SfM photogrammetric technique underperformed ALS in capturing the terrain surface under increasingly denser canopy cover, resulting in point density of less than 1 ground point per m2 and mean difference from ALS terrain surface of 0.12 m. This shortcoming caused errors that were propagated into the estimation of canopy properties, including the individual tree height (root mean square error of 0.92 m for ALS and 1.30 m for SfM). Differences were also seen in the estimates of canopy cover derived from the SfM (50%) and ALS (63%) pointclouds. Although ALS is capable of providing more accurate estimates of the vertical structure of forests across the larger range of canopy densities found in this study, SfM was still found to be an adequate low-cost alternative for surveying of forest stands.

Item Details

Item Type:Refereed Article
Keywords:digital terrain model, tree height, canopy cover, forest structure, unmanned aerial vehicle (UAV), LIDAR airborne laser scanning, structure from motion
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Forestry sciences
Research Field:Forestry management and environment
Objective Division:Plant Production and Plant Primary Products
Objective Group:Forestry
Objective Field:Forestry not elsewhere classified
UTAS Author:Wallace, LO (Dr Luke Wallace)
UTAS Author:Lucieer, A (Professor Arko Lucieer)
UTAS Author:Malenovsky, Z (Dr Zbynek Malenovsky)
UTAS Author:Turner, D (Dr Darren Turner)
ID Code:110361
Year Published:2016
Web of Science® Times Cited:374
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2016-07-25
Last Modified:2017-10-30
Downloads:256 View Download Statistics

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