Terrestrial laser scans - Riegl VZ400, raw instrument files and ancillary data, Australian field sites

Terrestrial laser scans - Riegl VZ400, raw instrument files and ancillary data, Australian field sites

Figure 1: Apparent reflectance (left) and range (right) hemispherical images from Riegl VZ400 scans at the Queensland DSITIA GOLD0101 long-term monitoring plot.

Link to Data

Data licence and Access rights

Abstract

Ground lidar, also known as Terrestrial Laser Scanning (TLS), is a ranging instrument that provides detailed 3D measurements directly related to the quantity and distribution of plant materials in the canopy. Measurements can be used for applications requiring quantification of vegetation structure parameters, tree and stand reconstruction, and terrain analysis.

Scans have been collected in Australia using two Riegl VZ400 waveform recording TLS instruments. One is co-owned and operated by the Remote Sensing Centre, Queensland Department of Science, Information Technology, Innovation and the Arts (DSITIA) and the TERN Auscover Brisbane Node, University of Queensland. The second is owned and operated by Wageningen University, Netherlands.

An automated TLS processing system has been developed by the Remote Sensing Centre, Queensland Department of Science, Information Technology, Innovation, and the Arts (DSITIA) using the Riegl RiVLib and RiWaveLib C++ libraries and the Sorted Pulse Data Library (SPDLib; Bunting et al., 2013b). Data is made available in published open standards including compress LAS format (LAZ; ASPRS, 2010) and the HDF-5 Sorted Pulse Data format (SPD; Bunting et al., 2013a).

Spatial and Temporal extents

Point of contact

Credit

The following organisations contributed to the data collection:

• Joint Remote Sensing Research Program
• University of Wageningen
• University of Adelaide (Ausplots)
• CSIRO

Keywords

There are three main thesauri that AusCover recommends:

1. Global Change Master Directory (http://gcmd.nasa.gov)
2. Climate and Forecast (CF) convention standard names (http://cfconventions.org/standard-names.html).
3. Fields of Research codes (http://www.abs.gov.au/ausstats/abs@.nsf/0/6BB427AB9696C225CA2574180004463E?opendocument).

Data quality

Validation status

There has been no absolute validation of biophysical products produced from the Riegl VZ400 in Australian Ecosystems. An exception is Calders et al. (2014), who found that estimates of canopy height from the Riegl VZ400 were within x% of estimates from airborne lidar across five sites ranging from open woodland to closed forest. A large area validation of these parameters is forthcoming for estimates of stem diameter, stand basal area, and canopy height as part of the TERN Wide Synthesis B project. 

In a comparison of commercial TLS instruments in Brisbane, Newnham et al. (2012) found PAVD profiles from a Riegl VZ1000 detected more material present in the upper canopy compared to a FARO Focus-3D, Leica C-10, and Leica HDS5000. Estimates were also stable across different pulse angular spacing, a result replicated by Calders et al. (in review). Newnham et al. (2012) also found that PAVD profiles were within x% of theoretical profiles generated from field measurement.

Further comparisons of ground lidar instrumentation and algorithms are being undertaken through the Terrestrial Laser Scanning International Interest Group (TLSIIG; http://tlsiig.bu.edu). See Armston et al. (2013) for further information.

Related products

References

Armston, J., Newnham, G, Strahler, A., Schaaf, C., Danson, M., Gaulton, R., Zhang, Z., Disney, M., Sparrow, B., Phinn, S., Schaefer, M., Burt, A., Counter, S., Erb, A., Goodwin, N., Hancock, S., Howe, G., Johansen, K., Li, A., Lollback, G., Martle, J., Muir, J., Paynter, I., Saenz, E., Scarth, P., Tindall, D., Walker, L., Witte, C., Woodgate, W., Wu, D. 2013. Intercomparison of terrestrial laser scanning instruments for assessing forested ecosystems: A Brisbane field experiment. AGU 2013 Fall Abstracts.

Bunting, P., Armston, J., Lucas, R., Clewley, D., 2013a. Sorted pulse data (SPD) library. Part I: A generic file format for lidar data from pulsed laser systems in terrestrial environments. Computers & Geosciences, 56: 197-206.

Bunting, P., Armston, J., Clewley, D., Lucas, R., 2013b. Sorted pulse data (SPD) library. Part II: A processing framework for lidar data from pulsed laser systems in terrestrial environments. Computers & Geosciences, 56: 207-215.

Calders, K., Armston, J., Newnham, G. Herold, M., Goodwin, N. In review.  Implications of sensor configuration and topography on vertical plant profiles derived from terrestrial LiDAR. Agricultural and Forest Meteorology.

Newnham, G., Armston, J., Muir, J., Goodwin, N., Culvenor, D., Pusche, P., Nystrom, M., Johansen, K., 2012. Evaluation of terrestrial laser scanners for measuring vegetation structure. CSIRO Sustainable Agriculture Flagship, available on https://publications.csiro.au/rpr/pub?pid=csiro:EP124571.

Sampling strategy

Data is collected at one or more sampling points at a plot, depending on the protocol. There are currently five separate sampling protocols used for ground lidar acquisition. The sampling design for each protocol with multiple scan positions are illustrated below. The specific protocol used and deviations from this strategy are outlined in the associated shapefile/KMZ file for this data set.

1. Plot centre (single scan)
2. Star transect (four scans)
3. Cross 40m (five scans)
4. Cross 25m (five scans)
5. Square (five scans)

When a scan position was established, the scanner was set-up as follows:

1. There must be no material within 1.5 m range of the scanner. The scan position should be moved a short distance if necessary.
2. The nominal height above ground of the scanner is typically 1.6 m. Scanner height is determined from the measured data.

Product version history

Instrument data filenaming convention

Filenames for instrument data conforms to the AusCover standard naming convention. The standard form of this convention is:

<sensor category code><instrument code><product code>_<longitude>e<latitude>s_<yyyymmdd>_<processing stage code>_<additional dataset specific tags>

Details for the unique codes used for this dataset can be found in the following table.

Shapefile/KMZ file attribute metadata

Metadata history