Terrestrial laser scans - Riegl VZ400, individual tree point clouds and cylinder models, Rushworth Forest

Terrestrial laser scans - Riegl VZ400, individual tree point clouds and cylinder models, Rushworth Forest

Figure 1: TLS point cloud and cylinder model for an individual Eucalyptus leucoxylon tree (RUSH07: TreeID 4)

Link to the data

Data licence and Access rights

Abstract

Terrestrial laser scans were acquired in native Eucalypt Open Forest (dry sclerophyll Box-Ironbark forest) in Victoria, Australia. Two plots (RUSH06 and RUSH07) with a 40 m radius were established in Rushworth forest and partially harvested in May 2012 to acquire accurate estimates of above-ground biomass. The main tree species in these plots were Eucalyptus leucoxylon, Eucalyptus microcarpa and Eucalyptus tricarpa. Single trees were extracted from the TLS data and quantitative structure models were used to estimate the tree volume directly from the point cloud data. Above-ground biomass was inferred from the derived volumes and basic wood density information, and compared with estimates of above-ground biomass derived from allometric equations and destructive sampling. See Calders et al. (2014) and Murphy et al. (2014) for further information.

Spatial and Temporal extents

Point of contact

Credit

1. Wageningen University, Netherlands
2. CSIRO Land and Water
3. Department of Geography, University College London
4. School of Land and Environment, University of Melbourne
5. Department of Mathematics, Tampere University of Technology
6. Environmental Sensing Systems, Melbourne
7. Remote Sensing Centre, Queensland Department of Science, Information Technology, Innovation and the Arts
8. Joint Remote Sensing Research Program, University of Queensland

Keywords

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1. Global Change Master Directory (http://gcmd.nasa.gov)
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3. Fields of Research codes (http://www.abs.gov.au/ausstats/abs@.nsf/0/6BB427AB9696C225CA2574180004463E?opendocument).

Data quality

The quality of point clouds and derived cylinder model are dependent on registration accuracy. Reflecting targets were distributed throughout the plot and were used to register the scan locations using the Riegl RiSCAN PRO software. The average standard deviation of the registered point clouds was 0.0129 m with values for individual scans ranging from 0.0062 m to 0.0226 m.

Validation status

AGB estimates derived from TLS show a high agreement with the reference values from destructive sampling, with a concordance correlation coefficient (CCC) of 0.98. The agreement between AGB estimates from allometric equations and the reference is lower (CCC = 0.68 to 0.78). The TLS approach shows a total AGB overestimation of 9.68% compared to an underestimation of 36.57% to 29.85% for the allometric equations.

Sampling strategy

Data was collected at five sampling points in a plot using a cross sampling protocol, as illustrated in Figure 2 below. To operate the scanner must necessarily be placed in a gap, so any deviations from the nominal sampling location illustration below are outlined in the associated shapefile/KMZ file for this data set.

Figure 2: Sampling design for terrestrial laser scans at RUSH06 and RUSH07.

Instrument data naming convention

Individual tree point clouds

gpv1_[plotname]_[treeID]_pts.txt

gpv1:

sensor category (gp): ground LiDAR
instrument (v1): Riegl VZ400

Individual tree cylinder models

gpv1_[plotname]_[treeID]_[numberOfRun]_cylmodel.txt

gpv1:

sensor category (gp): ground LiDAR
instrument (v1): Riegl VZ400

Data attributes

Individual tree point clouds

COLUMN 1: x[m]
COLUMN 2: y[m]
COLUMN 3: z[m]
The coordinate system is oriented to true north and relative to the centre of the plot (0,0,0).

Individual tree cylinder models

COLUMN 1: Radii of the cylinders
COLUMN 2: Lengths of the cylinders
COLUMN 3: Starting points of the cylinders, x-coordinate
COLUMN 4: Starting points of the cylinders, y-coord
COLUMN 5: Starting points of the cylinders, z-coord
COLUMN 6: Axes of the cylinders, x-component
COLUMN 7: Axes of the cylinders, y-comp
COLUMN 8: Axes of the cylinders, z-comp
COLUMN 9: Parent cylinder of each cylinder
COLUMN 10: Extension cylinder of each cylinder
COLUMN 11: Branch of the cylinders
COLUMN 12: Branch order of the cylinders
COLUMN 13: Running index of the cylinders in the branch (1 = base)
COLUMN 14: Logical vector indicating cylinders that are added to fill gaps
The coordinate system is oriented to true north and relative to the centre of the plot (0,0,0).

Related products

References

Product version history

Metadata history