Beagle Marine Park backscatter data 2018

Brief description

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.

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Maintenance and Update Frequency: asNeeded

Statement: The Beagle Marine Park Survey 2018, GA-0364 was acquired by Geoscience Australia (GA), the University of Tasmania (UTAS) between 17 and 26 June 2018, led by Dr. Scott Nichol (GA) and Dr. Neville Barrett (UTAS). This dataset was acquired using Kongsberg's SIS acquistion software and processed onboard using CMST-GA MB Process v15.04.04.0 software by Justy Siwabessy. Processing: 1. Multibeam data were collected using a Kongsberg EM2040C multibeam echosounder system, mounted in the moon pool of the MV Bluefin. Motion referencing and navigation data were collected with an Applanix Position and Orientation system and a C-Nav GPS system, respectively. Multibeam data were acquired using Kongsberg’s Seabed Information System (SIS) software. 2. These data were processed using the multibeam backscatter CMST-GA MB Process v15.04.04.0 (x64) toolbox software co-developed by the Centre for Marine Science and Technology (CMST) at Curtin University of Technology and GA (described in Gavrilov et al., 2005; Parnum and Gavrilov 2011). 3. The process involved removal of the system transmission loss, removal of the system model, calculation of the incidence angle, correction of the beam pattern, calculation of the angular backscatter response within a sliding window of 100 pings with a 50% overlap in a 1° bin, removal of the angular dependence, and restoration to the backscatter strength at an angle of 40°. The final processed backscatter data were then gridded to 1 m horizontal resolution and exported for display and analysis. In GA, further process was conducted by Justy Siwabessy to fine tune beam pattern correction. 4. The processed data was finally exported as grids in the optimum resolution the data can provide. Metadata: The multibeam bathymetry was acquired by the following survey: - Survey Name: Beagle Marine Park Survey 2018 (GA-0364) - Vessel Name: RV Bluefin - Institutions: Geoscience Australia, UTAS - Country: Australia - Operator: AMC, UTAS - Multibeam system: Kongsberg EM2040C - Year of installation: 2014 - Nominal sonar frequency: 300 kHz - Number of beams: 400 beams - Beamwidth across track: 1.3 degrees - Beamwidth along track: 1.3 degrees - Pulse length: variable - Selectable depth range: 5 m - 60 m - Vessel speed: 7 - 10 knots - Start Date: 17/06/2018 - End Date: 26/06/2018 - Start Port: Launceston - End Port: Stanley - Processing software: CMST-GA MB Process v15.04.04.0 - Grid resolution: 1 m - Number of grids: 11 - Total surface coverage: 366 km2 - Horizontal Datum: WGS84 UTM-55S This dataset is published with the permission of the CEO, Geoscience Australia