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Product pages » Terrestrial laser scans - DWEL, processed instrument files and ancillary data, Australian field sites

Terrestrial laser scans - DWEL, processed instrument files and ancillary data, Australian field sites

Last modified by Matt Paget on 2016/07/02 05:07

Terrestrial laser scans - Dual Wavelength Echidna Lidar (DWEL), processed instrument files and ancillary data, Australian field sites (UNDER CONSTRUCTION)

22 - Copy.png
Figure 1: Intensity image created from the 1556 nm laser output of DWEL. Scan was taken in the Himalayan Cedar forest at the National Arboretum Canberra.

Link to the data

DescriptorData linkLayer name
Persistent URLhttp://www.auscover.org.au/purl/tls-dwel-qa-all-sites
GeoNetwork recordNot available yet

Shapefile of scan detailsNot available yet
KMZ of scan detailsNot available yet
DWEL data/productshttp://qld.auscover.org.au/thredds/catalog/auscover/field_validation/dwel/catalog.htmlIn production
DWEL Bloghttp://ozdwel.blogspot.com.au/

Data licence and Access rights

ItemDetail
RightsCopyright 2014-2016 CSIRO. Rights owned by the Commonwealth Scientific and Industrial Research Organisation (CSIRO). Rights licensed subject to Creative Commons Attribution (CC BY).
LicenceCreative Commons Attribution 3.0 License, http://creativecommons.org/licenses/by/3.0.
AccessThese data can be freely downloaded and used subject to the CC BY licence. Attribution and citation is required as described at http://www.auscover.org.au/citation. We ask that you send us citations and copies of publications arising from work that use these data.

Abstract or Summary

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 the Australia version of the dual wavelength echidna lidar (DWEL), a full-waveform recording TLS instrument. This instrument is co-owned and operated the TERN Auscover Canberra Node and CSIRO.

An automated TLS processing system has been developed by CSIRO in conjunction with Boston University using ENVI + IDL and python in addition to using the Sorted Pulse Data Library (SPDLib; Bunting et al., 2013b). Data is made available in published open standards including compressed LAS format (LAZ; ASPRS, 2010) and the HDF-5 Sorted Pulse Data format (SPD; Bunting et al., 2013a), as well as ascii format.

Spatial and Temporal extents

ItemDetail
Spatial resolution (metres)30m radius
Spatial coverage (degrees)110.000000 to 155.001329 E, -10.000000 to -45.000512 N
Temporal resolution1 day
Temporal coverage2014-06-01,ongoing
Sensor & platformDual Wavelength Terrestrial Laser Scanner
ItemDetail
Spatial representation typevector - point
Spatial reference systemWGS 84

Point of contact

ItemDetail
NameMichael Schaefer
OrganisationUniversity of New England / CSIRO
PositionPostdoctoral Research Fellow
Emailmichael.schaefer@csiro.au
RolepointOfContact
AddressCSIRO Black Mountain, Clunies Ross St, Acton ACT, 2601.
Telephone(02) 6246 5632

Credit

The following organisations contributed to the data collection:

  • The University of New England
  • CSIRO
  • Joint Remote Sensing Research Program

Keywords

ThesauriKeyword
GCMDEARTH SCIENCE > BIOSPHERE > VEGETATION > VEGETATION COVER
CFvegetation_area_fraction
FoREnvironmental Sciences > Ecological Applications = 0501

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

This is an initial version release of the DWEL data and products using the current processing software. Future data and products my improve with subsequent software fixes and instrument  calibration.

Validation status

There has been no absolute validation of biophysical products produced from the DWEL in Australian Ecosystems. However, comparisons of commercial ground lidar instruments as well as research instruments including DWEL, CBL and SALCA have been made in Australian Ecosystems. 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.

Sampling strategy

In the same manner as is done using the Riegl VZ400, DWEL 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, most common with DWEL)
  2. Star transect (four scans)
  3. Cross 40m (five scans)
  4. Cross 25m (five scans)
  5. Square (five scans)

tls_sampling_protocols.png

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

  1. There must be no material within 1.0 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 1.2 m. Scanner height is determined from the measured data as well as physically measured and recorded in the field.

Instrument data naming 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.

Data Naming ElementPossible Code(s)Descriptor
Standard Elements

     
sensor categorygpground lidar
instrumentdwDWEL
productwfwaveform
processing stageaa0   
aa1
aa2
raw instrument data (sensor coordinate system)
registered data (project coordinate system)
registered data with waveforms and photo RGB data
data projectionf0     
f1
f2
f3
Time sequential
Scan line/sample
Cartesian
Spherical

Shapefile/KMZ/Database file attributes

Same convention as for Riegl VZ400

FieldDescription (units)Format
supersiteAusCover calibration/validation siteText
collectionCode in naming convention –see instrument filenaming convention for detailsText
instumentCode in naming convention –see instrument filenaming convention for detailsText
productCode in naming convention –see instrument filenaming convention for det
ails
Text
sceneIdentifier for plot location given in longitude latitude combinationText
obs_timeDate and time of scan collectionDate/Time Stamp
scan_azimuthAzimuth of transect from plot centre to scan collection point in degrees from north (degrees)Integer
height_baseHeight from base of scanner plate (cm)Integer
height_optical_centreHeight optical centre of scanner plate (cm)Integer
battery_onYes/no categorical field whether battery is on scanner, as this affe
cts height measurements
Text
reflect_distance_nDistance to reflector on north transect, if exists (m)Float
reflect_sizeReflector diameter (mm)Integer
project_nameProject root name as recorded in scannerText
obs_keyUniqe identifier for site visit for data management purposesText
idId for data management purposesInteger
reflect_foundNumber of reflectors scan foundInteger
tilt_angleTilt angle of scanner (0 for ??, ??) (degrees)Integer
no_reflectTotal number of reflectors deployed
scan_distanceDistance to scanner along transect running from plot centre to sc
anner location (m)
Float
reflect_distance_sDistance to reflector on north transect, if exists (m)Float
reflect_distance_eDistance to reflector on north transect, if exists (m)Float
reflect_distance_wDistance to reflector on north transect, if exists (m)Float
reflect_distance_neDistance to reflector on north transect, if exists (m)Float
reflect_distance_seDistance to reflector on north transect, if exists (m)Float
reflect_distance_swDistance to reflector on north transect, if exists (m)Float
reflect_distance_nwDistance to reflector on north transect, if exists (m)Float
live_basal_areaBasal area estimate obtained via basal area sweep for live trees only (km/m^2)Float
total_basal_areaBasal area estimate obtained via basal area sweep for live trees only (kg/m^2)Float

Related products

ItemProduct link
SLATS star transecthttp://www.auscover.org.au/xwiki/bin/view/Product+pages/SLATS+Star+Transect+Data
Leaf area indexNot available yet
Hemispherical photographyhttp://www.auscover.org.au/xwiki/bin/view/Product+pages/Hemispherical+Photography
Riegl VZ400 TLShttp://www.auscover.org.au/xwiki/bin/view/Product+pages/TLS+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.

Li, Z., Jupp, D.L.B., Strahler, A.H., Schaaf, C.B., Howe, G., Hewawasam, K., Douglas, E.S., Chakrabarti, S., Cook, T.A., Paynter, I., Saenz, E.J., Schaefer, M., 2016. Radiometric Calibration of a Dual-Wavelength, Full-Waveform Terrestrial Lidar. Sensors, 16, 313.

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.

Product version history

Version labelDetail
1.0Initial release - data and products, contact for further information
*.las and *.txt file formats of scans are available upon request.

Other items

  • DWEL Blogspot to follow all of AusCover DWEL scanning activities: DWEL Blog
  • Terrestrial Laser Scanning International Interest Group: TLSIIG 

Metadata history

DateDetail
2016-04-13Metadata creation date
2016-04-13Updated / constructed page
Tags:
Created by Matt Paget on 2016/04/13 14:06

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