This record describes multibeam echosounder data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2020_V01, titled: “Development of William’s Ridge, Kerguelen Plateau: tectonics, hotspot magmatism, microcontinents, and Australia’s Extended Continental Shelf” between January 08 and March 06, 2020 departing from Henderson (WA) and returning back to Fremantle (WA). The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter at Rig Seismic Seamount, Williams Ridge, Broken Ridge and on associated transits. The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 2164 files totalling 174 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Tide corrections were not applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes multibeam echosounder data collected on RV Linnaeus voyage LI2019_V01, 'Ningaloo Deepwater Reefs Hydrographic Survey' which departed Hillary's Boat Harbour, Perth, WA on the 15th March 2019 and concluded at Coral Bay, WA on the 29th March 2019. The Kongsberg EM2040c multibeam echosounder (single transceiver) was used to acquire seafloor bathymetry and backscatter information (and watercolumn backscatter) offshores of Ningaloo Reef, WA. Transit data to and from nightly anchorages has also been recorded. The EM2040c provides a 1.3° by 1.3° transmit and receive angular resolution respectively (single transceiver). The echosounder's nominal frequency range was 200 kHz and it was operated in dual swath mode. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 140 files totalling 32.5 GB of raw .all data, and 103 files totalling 178 GB of raw .wcd in the dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Tide corrections were applied to the processed data in Caris using a GPS Tide based on the Applanix PosMV and Marinestar G4+ Ellipsoidal ht and thereafter reduced to AHD (Australian Height Datum) using a AusGeoid09 model. Processed data has had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request. The raw data is offline but is available on request.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2023_E01, 'Sea Trials and Calibrations' which departed Fremantle on the 06/01/2023 and returned to Fremantle on the 12/01/2023 (UTC). The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter around offshore Perth. The EM710 MKII provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 40 to 100 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 194 files totalling 27.2 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Bathymetry data contained in *.all format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2019_T03, "ORCA: Using the Investigator radar as a moving reference for the Australian operational radar network" which departed Darwin on the 23 December 2019 and returned to Henderson on the 2 January 2020. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter between Darwin and Henderson. The EM710 MKII provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 40 to 100 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 258 *.raw files totalling 70.4 GB and 257 *.wcd files totalling 464 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Tide corrections were not applied to the processed data. Processed data has had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.