This dataset contains multibeam sonar angular backscatter response curve data of area A1 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).

Geoscience Australia carried out marine surveys in southeast Tasmania in 2008 and 2009 (GA0315) to map seabed bathymetry and characterise benthic environments through observation of habitats using underwater towed video. Data was acquired using the Tasmania Aquaculture and Fisheries Institute (TAFI) Research Vessel Challenger. Bathymetric mapping was undertaken in seven survey areas, including: Freycinet Pensinula (83 sq km, east coast and shelf); Tasman Peninsula (117 sq km, east coast and shelf); Port Arthur and adjacent open coast (17 sq km); The Friars (41 sq km, south of Bruny Island); lower Huon River estuary (39 sq km); D Entrecastreaux Channel (7 sq km, at Tinderbox north of Bruny Island), and; Maria Island (3 sq km, western side). Video characterisations of the seabed concentrated on areas of bedrock reef and adjacent seabed in all mapped areas, except for D Entrecastreaux Channel and Maria Island. The "challenger" folder contains processed multibeam backscatter data of the South East Tasmania Shelf. The SIMRAD EM3002 multibeam backscatter data were processed using the CMST_GA MB Process, a multibeam processing toolbox codeveloped by Geoscience Australia and Curtin University of Technology.

This dataset contains hardness classification data 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).

Geoscience Australia carried out a marine survey on Carnarvon shelf (WA) in 2008 (SOL4769) to map seabed bathymetry and characterise benthic environments through co-located sampling of surface sediments and infauna, observation of benthic habitats using underwater towed video and stills photography, and measurement of ocean tides and wave-generated currents. Data and samples were acquired using the Australian Institute of Marine Science (AIMS) Research Vessel Solander. Bathymetric mapping, sampling and video transects were completed in three survey areas that extended seaward from Ningaloo Reef to the shelf edge, including: Mandu Creek (80 sq km); Point Cloates (281 sq km), and; Gnaraloo (321 sq km). Additional bathymetric mapping (but no sampling or video) was completed between Mandu creek and Point Cloates, covering 277 sq km and north of Mandu Creek, covering 79 sq km. Two oceanographic moorings were deployed in the Point Cloates survey area. The survey also mapped and sampled an area to the northeast of the Muiron Islands covering 52 sq km.. 0308_carnarvon_shelf contains processed multibeam backscatter data of the Carnarvorn Shelf. The SIMRAD EM3002 multibeam backscatter data were processed using the CMST-GA MB Process, a multibeam processing toolbox co-developed by Geoscience Australia and Curtin University of Technology.

A bathymetric survey of Darwin Harbour was undertaken during the period 24 June to 20 August 2011 by iXSurvey Australia Pty Ltd for the Department of Natural Resources, Environment, The Arts and Sport (NRETAS) in collaboration with Geoscience Australia (GA), the Darwin Port Corporation (DPC) and the Australian Institute of Marine Science (AIMS) using GA's Kongsberg EM3002D multibeam sonar system and DPC's vessel Matthew Flinders.

Acoustic backscatter from the seafloor is a complex function of signal frequency, seabed roughness, grain size distribution, benthos, bioturbation, volume reverberation and other factors. Angular response is the variation in acoustic backscatter with incident angle and it is considered be an intrinsic property of the seabed. The objective of the study was to illustrate how the combination of a self-organising map (SOM) and hierarchical clustering can be used to develop an angular response facies map for Point Cloates, northwest Australia; demonstrate the cluster visualisation properties of the technique; and highlight how the technique can be used to investigate environmental variables that influence angular response.

The Petrel Sub-basin Marine Environmental Survey GA-0335, (SOL5463) was acquired by the RV Solander during May 2012 as part of the Commonwealth Government's National Low Emission Coal Initiative (NLECI). The survey was undertaken as a collaboration between the Australian Institute of Marine Science (AIMS) and GA. The purpose was to acquire geophysical and biophysical data on shallow (less then 100m water depth) seabed environments within two targeted areas in the Petrel Sub-basin to support investigation for CO2 storage potential in these areas.

This report is the third of three reports that provide the scientific analyses and interpretations resulting from a four-year collaborative habitat mapping program undertaken within the Darwin and Bynoe Harbour region by Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and the Northern Territory Government Department of Environment and Natural Resources (DENR). This program was made possible through offset funds provided by the INPEX-operated Ichthys LNG Project to DENR, and co-investments from GA and AIMS.

This resource includes multibeam sonar backscatter data for Beagle Marine Park (Bass Strait) collected by Geoscience Australia (GA) and the Institute for Marine & Antarctic Studies (University of Tasmania; UTAS) during the period 17 – 26 June 2018 on the RV Bluefin. The survey was undertaken as a collaborative project funded through the National Environmental Science Program Marine Biodiversity Hub, with co-investment by GA and UTAS. The purpose of the project was to build baseline information for benthic habitats in the Beagle Marine Park that will support ongoing environmental monitoring within the South-east Marine Park Network as part of the 10-year management plan (2013-2023). Data acquisition for the project was completed during three separate voyages: Phase 1 - Seabed mapping by multibeam sonar; Phase 2 – Seabed imagery acquisition by Autonomous Underwater Vehicle, and sediment sampling; Phase 3 – Survey of demersal fish communities using Baited Remote Underwater Video (BRUVs). This dataset from Phase 1 comprises 11 backscatter grids derived from multibeam sonar data gridded at 1 m spatial resolution, covering a combined area of 364 km2. A detailed report on the survey is provided in: Falster, G., Monk, J., Carroll, A., Siwabessy, J., Deane, A., Picard, K., Dando, N., Hulls, J., Nichol, S., Barrett, N. 2019. Australian Marine Park Baseline and Monitoring Survey: Post Survey Report, Beagle Marine Park, South-east Marine Park Network. Report to the National Environmental Science Program, Marine Biodiversity Hub.

Geoscience Australia (GA) has an active research interest in using multibeam bathymetry, backscatter data and their derivatives together with geophysical data, sediment samples, biological specimens and underwater video/still footage to create seabed habitat maps. This allows GA to provide spatial information about the physical and biological character of the seabed to support management of the marine estate. The main advantage of using multibeam systems over other techniques is that they provide spatially continuous maps that can be used to relate to physical samples and video observations. Here we present results of a study that aims to reliably and repeatedly delineate hard and soft seabed substrates using bathymetry, backscatter and their derivatives. Two independent approaches were employed: (1) un-supervised classification-based, using a two stage clustering method; and (2) supervised prediction-based, using the Random Forest method. Data for the analysis were collected by Geoscience Australia and the Australian Institute of Marine Science (AIMS) over two consecutive surveys in 2009 & 2010 in eastern Joseph Bonaparte Gulf using the AIMS Research Vessel Solander. The results indicate that the approaches developed are robust and reliable because of their overall classification accuracies (78% and 87% respectively). They are consistent with the current state of knowledge on geoacoustics i.e. the most 'acoustically hard' substrates are dominated by hard-grounds and relatively coarse seabed sediments, and the most 'acoustically soft' substrates are associated with finer sediments. Patterns associated with geomorphic facies and biological categories are also observed. For instance, 'hard' classes are mostly found on banks and are always associated with mixed sponge and coral gardens whereas 'soft' classes mainly occur in valleys where fine-grained sediments are concentrated. These results demonstrate the utility of acoustic data to broadly and objectively characterise the seabed substrate and thereby inform our understanding of the distribution of key habitat types.