This record describes multibeam echosounder data collected on RV Investigator voyage IN2023_E03, titled "Trials & Calibrations", which was segmented into 3 legs, departing Hobart on September 13 and ending in Sydney on September 30, 2023. Leg 1 (Hobart to Hobart) took place between 13-16 Sep, Leg 2 (Hobart to Hobart) between 16-25 Sep and Leg 3 (Hobart to Sydney) between 26-30 Sep. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry, backscatter and watercolumn backscatter in Storm Bay, offshore to the southeast of Tasman Peninsula and between Hobart and Sydney. 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 332 files totalling 60.6 GB of raw data and 332 files totalling 396 GB of wcd 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. GPS tide was computed using the EGM2008 model and 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.

This record describes scientific split-beam echosounder data collected on the RV Investigator voyage IN2023_E03, titled "Trials & Calibrations", which was segmented into 3 legs, departing Hobart on September 13 and ending in Sydney on September 30, 2023. Leg 1 (Hobart to Hobart) took place between 13-16 Sep, Leg 2 (Hobart to Hobart) between 16-25 Sep and Leg 3 (Hobart to Sydney) between 26-30 Sep. The Simrad EK80 wide band transceivers (WBT) 38, 70, 120, 200 kHz and the EK60 split-beam GPT 18 kHz were calibrated during Leg 2 of the voyage. The calibration was undertaken at anchor in the Derwent Estuary on September 18, 2023 with the 38mm sphere deployed at 03:00 (UTC) and calibration recording conducted between 07:14 - 10:06 (UTC). The EK80 WBTs were calibrated using default settings for only CW modes. Due to line snagging issues under the hull and resulting time limitations, no calibration was undertaken for the 333 kHz or for the remaining EK60 GPTs. The results of the calibration were not applied immediately to the EK80 (pending further onshore analysis). All frequencies were logged sporadically for the extent of the voyage. The frequencies were set to passive for periods during the voyage when conducting other system calibrations or during shallow water mapping when interference was noted on the mapping system (EM710) from the 70 and 120kHz frequencies mainly. Data are stored in .raw, .bot and *.idx format at CSIRO. There are 519 files totalling 45.6 GB of raw data in this dataset. No processing has been conducted on this data. Additional information regarding this dataset 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 IN2020_V06, titled "Probing the Australian-Pacific Plate Boundary: Macquarie Ridge in 3-D." The voyage took place between October 8 and November 3, 2020 departing from Hobart (TAS) and arriving in Hobart (TAS). The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter around Macquarie Island and during transit to the survey area. 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 667 files totalling 32.4 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 Investigator voyage IN2023_V06, titled: "Understanding Eddy Interactions and Their Impacts In the East Australian Current System." The voyage took place between October 9 and November 2, 2023, departing from Sydney (NSW) and returning to Sydney. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter around NSW coast survey area. 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 760 files totalling 39.6 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. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Processed line data are available in .gsf and ascii format, and processed bathymetry 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.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2024_E01, 'Trials and Calibrations' which departed Hobart on the 28th October and returned to Hobart on the 6th November 2024. The Kongsberg EM124 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter. NOTE: The system was newly installed in Singapore as part of the vessel's mid-life refit and this voyage constituted the formal Sea Acceptance Test for the system. The EM124 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 130 files totalling 6.31 GB of raw data and 131 files totalling 12.5 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2024_E01, 'Trials and Calibrations' which departed Hobart 28th October and returned to Hobart on the 6th November 2024. The Kongsberg EM712 multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter. NOTE: The system was newly installed in Singapore as part of the vessel's mid-life refit and this voyage constituted the formal Sea Acceptance Test for the system. The EM712 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 .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 127 files totalling 24.8 GB of raw data and 127 files totalling 107 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2023_V06, titled: "Understanding Eddy Interactions and Their Impacts In the East Australian Current System." The voyage took place between October 9 and November 2, 2023, departing from Sydney (NSW) and returning to Sydney. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter around NSW coastal areas. 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 18 files totalling 2.29 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. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Processed line data are available in .gsf and ascii format, and processed bathymetry 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.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2024_E01, 'Trials and Calibrations' which departed Hobart on the 28th October and returned to Hobart on the 6th November 2024. The Kongsberg EM2040-MKII multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter. NOTE: The system was newly installed in Singapore as part of the vessel's mid-life refit and this voyage constituted the formal Sea Acceptance Test (SAT) for the system. The EM2040 provides a 0.4 degree by 0.7 degree angular resolution. The echosounder's nominal frequency is 400 kHz (with a range of 200-700 kHz) and it operated in dual swath mode. Data are stored in .kmall raw format for bathymetry and backscatter and .kmwcd format for watercolumn backscatter at CSIRO. There are 135 files totalling 14.9 GB of raw data and 135 files totalling 287 GB of watercolumn data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.kmall format are corrected for motion and position. GPS tide was computed using the EGM2008 model and applied to the processed data. Processed data has had outliers removed. Additional information regarding this dataset, including further information on processing streams, is contained in the GSM data acquisition and processing report.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2017_E04, Trials voyage, which departed Hobart on the 7th of December 2017 and returned to Hobart on the 11th of December 2017. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information around southeast Tasmania. Patch test calibrations for the EM710 were performed on this voyage. 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 at CSIRO. There are 34 files totaling 1.68 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.

This record describes multibeam echosounder data collected on RV Investigator voyage IN2022_V06, titled "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27 degrees South." The voyage took place between July 14 and July 30, 2022 (AEST), departing from Brisbane and returning to Brisbane. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn around Brisbane 27 degrees South. 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 293 files totalling 21.1 GB of .all raw data and 284 files totalling 26.6 GB of .wcd 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. GPS Tide corrections were applied to processed data. Calculations are based on the Applanix PosMV Marinestar G4+ Ellipsoidal heights. 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.