Terrestrial Laser Scanning: Can we see the wood for the trees. Kenneth Olofsson SLU

Transcription

1 Terrestrial Laser Scanning: Can we see the wood for the trees Kenneth Olofsson SLU

2 Terrestrial laser scanning (TLS) A laser scanner placed in the area of interest scans 360º, resulting in a 3D point cloud Signal analysis techniques can be used to derive forestry parameters from the 3D point cloud

3 Why use TLS data? Could make field inventory more efficient and reduce the risk of errors due to the human factor An increased amount of information from the field survey The positions of the tree stems can be derived for co-registration with airborne data

4 Forestry parameters extracted from TLS-data Tree position Stem diameter (dbh) Stem profile Tree height Volume Stem shapes Branch structure Leaf area index

5 Extract trees from TLS data

6 TLS results Stem profile RMSE ~1 cm Kenneth Olofsson and Johan Holmgren Single Tree Stem Profile Detection Using Terrestrial Laser Scanner Data, Flatness Saliency Features and Curvature Properties Forests 2016, 7(9), 207; doi: /f

7 Single/multiple scan setup A: Single scan Pro:Short scanning time, Easy to use Con: Shading of trees B: Multiple scan Pro: High point density, Small amount of shading Con: Accurate co-registration necessary. Scanning time is long

8 Simulated TLS field plot

9 Examples of shading of stems in TLS field plots The whole stem is visible At least half of the stem is visible At least a small part of the stem is visible The center of the stem is visible The left edge of the stem is visible The right edge of the stem is visible The stem is shaded

10 Shaded area in TLS plots

11 Shaded area in TLS plots

12 Estimating stems/ha

13 Estimating stems/ha

14 Estimating stems/ha

15 Estimating stems/ha

16 Stem diameter distributions

17 Stem diameter distributions

18 Gaussian stem diameter distribution

19 Clustered positions of the trees, Gaussian stem diameter distribution

20 References Aschoff, T., Thies, M., and Spiecker, H., 2004, Describing forest Stands using Terrestrial Laserscanning. In proceedings of the XXth ISPRS Congress, July 12-23, 2004, Istanbul, Turkey, Aschoff, T. and Spiecker, H., Algorithms for the automatic detection of trees in laser scanner data. In proceedings of the ISPRS workshop Laser-Scanners for Forest and Landscape Assessment, October 3-6, 2004, Freiburg, Germany. Bienert, A., Scheller, S., Keane, E., Mohan, F., and Nugent, C., 2007, Tree Detection and Diameter Estimations by Analysis of Forest Terrestrial Laserscanner Point Clouds. In proceedings of the ISPRS Workshop on Laser Scanning 2007 and SilviLaser 2007, Espoo, September 12-14, 2007, Finland, Brolly, G. and Király, G., Algorithms for Stem Mapping by Means of Terrestrial Laser Scanning. Acta Silv. Lign. Hung., Vol. 5 (2009) Chum, O., Two-View Geometry Estimation by Random Sampling and Consensus. PhD-thesis. Center for Machine Perception Department of Cybernetics Faculty of Electrical Engineering Czech Technical University in Prague.

21 References 2 Erikson, M. and Vestlund, K Finding tree stems in laser range images of young mixed stands to perform selective cleaning. Scandlaser 2003, Umeå Sweden. Forsman, P. and Halme, A., D Mapping of Natural Environments With Trees by Means of Mobile Perception. IEEE transactions on robotics, vol. 21, no. 3, june Gorte, B. and Winterhalder, D., Reconstruction of laser-scanned trees using filter operations in the 3d raster domain. In proceedings of the ISPRS workshop Laser-Scanners for Forest and Landscape Assessment, October 3-6, 2004, Freiburg, Germany. Haala, N.,, R., Thies, M., and Aschoff, T., 2004, Combination of terrestrial laser scanning with high resolution panoramic images for investigations in forest applications and tree species recognition. In proceedings of the ISPRS Panoramic Photogrammetry Workshop, February 19-22, 2004, Dresden, Germany. Henning, J.G. and Radtke, P.J., 2006, Detailed stem measurements of standing trees from ground-based scanning lidar. Forest Science, 52,

22 References 3 Hopkinson, C., Chasmer, L., Young-Pow, C., and Treitz, P., 2004, Assessing forest metrics with a ground-based scanning lidar. Canadian Journal of Forest Research-Revue Canadienne de Recherche Forestiere, 34, Hosoi, F, and Omasa, K, Voxel-Based 3-D Modeling of Individual Trees for Estimating Leaf Area Density Using High-Resolution Portable Scanning Lidar. IEEE Transactions on geoscience and remote sensing, vol. 44, no. 12, Liang, X Litkey, P, Hyyppä, J, Kaartinen, H., Vastaranta, M., and Holopainen, M., Automatic stem location mapping using TLS for plot-wise forest inventory. SilviLaser 2009, Oct , 2009 College Station, Texas, USA. Lindberg, E., Holmgren, J., Olofsson, K., and Olsson, H., Estimation of stem attributes using a combination of terrestrial and airborne laser scanning. Silvilaser 2010, Freiburg, Tyskland. Olofsson, K., E. Lindberg and Holmgren, J., A method for linking field-surveyed and aerial-detected single trees using cross correlation of position images and the optimization of weighted tree list graphs. SilviLaser 2008, 8th international conference on LiDAR applications in forest assessment and inventory., Heriot-Watt University, Edinburgh, UK, SilviLaser 2008 Organizing Committee, Edinburgh: Forest Research. Olofsson, K., and Holmgren, J. Single Tree Stem Profile Detection Using Terrestrial Laser Scanner Data, Flatness Saliency Features and Curvature Properties. Forests 2016, 7(9)

23 References 4 Pfeifer, N. and Winterhalder, D., 2004, Modelling of Tree Cross Sections from Terrestrial Laser-Scanning Data with Free-Form Curves. In proceedings of the ISPRS workshop Laser-Scanners for Forest and Landscape Assessment, October 3-6, 2004, Freiburg, Germany. Raumonen, P., Kaasalainen, M., Åkerblom, M., Kaasalainen, S., Kaartinen, H., Vastaranta, M., Holopainen, M., Disney, M. and Lewis, P.,. Fast Automatic Precision Tree Models from Terrestrial Laser Scanner Data. Remote Sensing, 2013, 5(2), Shan, J. and Toth, C, Topographic laser ranging and scanning. Principles and processing. Taylor & Francis Group, London New York. Simonse, M., Aschoff, T., Spiecker, H. and Thies, M Automatic determination of forest inventory parameters using terrestrial laser scanning. Proceedings of the ScandLaser Scientific Workshop on Airborne Laser Scanning of Forests, Umea, Sweden, 3 Á/4 September 2003, pp. 252 Á/258. ISSN 1401 Á/1204. Tanaka, T., Yamaguchi, J., and Takeda, Y., 1998, Measurement of forest canopy structure with a laser plane range-finding method - development of a measurement system and applications to real forests. Agricultural and Forest Meteorology, 91, Tanaka, T., Park, H., and Hattori, S., 2004, Measurement of forest canopy structure by a laser plane range-finding method. Improvement of radiative resolution and examples of its application. Agricultural and Forest Meteorology, 125, Thies, M., Pfeifer, N., Winterhalder, D. and Gorte, B.G.H., 2004, Three-Dimensional Reconstruction of Stems for Assessment of Taper, Sweep and Lean Based on Laser Scanning of Standing Trees. Scandinavian Journal of Forest Research, 19,