Brief description
This dataset contains probability of seabed hardness data (multibeam angular backscatter response derived product) from seabed mapping surveys on the Van Diemen Rise in the eastern Joseph Bonaparte Gulf of the Timor Sea. The survey was conducted under a Memorandum of Understanding between Geoscience Australia (GA) and the Australian Institute of Marine Science (AIMS) in two consecutive years 2009 (GA survey number GA-0322 and AIMS survey number SOL4934) and 2010 (GA survey number GA-0325 and AIMS survey number SOL5117). The surveys obtained detailed geological (sedimentological, geochemical, geophysical) and biological data (macro-benthic and infaunal diversity, community structure) for the banks, channels and plains to investigate relationships between the physical environment and associated biota for biodiversity prediction. The surveys also provide Arafura-Timor Sea, and wider northern Australian marine region context for the benthic biodiversity of the Van Diemen Rise. Four study areas were investigated across the outer to inner shelf. Refer to the GA record 'Methodologies for seabed substrate characterisation using multibeam bathymetry, backscatter, and video data: A case study for the Eastern Joseph Bonaparte Gulf, Northern Australia' for further information on processing techniques applied (GeoCat: 74092; GA Record: 2013/11)Lineage
Maintenance and Update Frequency: asNeeded
Statement: The extraction of angular response curves from the raw Simrad multibeam data was achieved using the multibeam backscatter CMST-GA MB Process v10.10.17.0 toolbox software co-developed by the Centre for Marine Science and Technology (CMST) at Curtin University of Technology and Geoscience Australia (described in Gavrilov et al., 2005a, 2005b; Parnum, 2007). A number of corrections were introduced to the data and the angular response curves were produced as the average response curve within the adopted sliding windows in which port and starboard swath were processed separately as part of the process of the removal of the backscatter angular dependence. Video-derived classes were used to locate the hard-bottomed seabed areas for which the angular backscatter response curves were extracted. Of those response curves, the lowest angular backscatter response curve was associated with the 'mixed patches/mixed gardens' class and the highest response curve with the 'mixed gardens (hard coral)' class. Of these lowest angular backscatter response curves, one for each study area was extracted and compared to all other angular backscatter response curves within its corresponding area for incidence angles between 0C and 60C using the Kolmogorov-Smirnov goodness of fit to estimate the probability (p-value) of hard bottom. Finally, the IDW interpolation technique was used to produce a continuous layer of the p-value of hard bottom for each study area.
Issued: 2013
text: westlimit=129.451; southlimit=-12.287; eastlimit=130.063; northlimit=-10.285
Subjects
AU-NT |
Backscatter Grid |
Earth Sciences |
Geology |
Marine Data |
Marine Geoscience |
NERP |
Published_External |
backscatter |
geoscience |
geoscientificInformation |
marine |
multibeam |
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Other Information
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Identifiers
- DOI : 10.4225/25/562EC8BD7018B
- URI : pid.geoscience.gov.au/dataset/ga/76347
- global : ddfea66e-adf6-04a9-e044-00144fdd4fa6
