This record describes multibeam echosounder data collected on RV Investigator voyage IN2024_V01, 'Multidisciplinary Investigations of the Southern Ocean' which departed Hobart on 05/01/2024 and returned to Fremantle on 05/03/2024. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter from Hobart, along the Antarctic ice edge to Fremantle. 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 135 files totalling 126.9 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 SVP data collected on RV Investigator voyage IN2024_V01, 'Multidisciplinary Investigations of the Southern Ocean' which departed Hobart on 05/01/2024 and returned to Fremantle on 05/03/2024. A total of 131 SVP casts were conducted over the duration of this voyage. Data are stored in ASCII format files with extention *.000 at CSIRO. 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 the Acoustic Doppler Current Profiler (ADCP) data collected from the Marine National Facility RV Investigator voyage IN2021_V01, titled: "Quantifying krill abundance for krill monitoring and management off the Australian Antarctic Territory". The voyage took place from Hobart (TAS) to Hobart between January 29 and March 24, 2021. Both the RDI Ocean Surveyor 150kHz ADCP and the RDI Ocean Surveyor 75kHz ADCP were run in narrowband for transit to and from the survey area. During survey transects the OS150 was used. Data was collected using UHDAS and post-processed using CODAS. Internal triggering was used for the transits to and from the survey site only. When run on transect lines or during target trawling, triggering was performed via KSYNC, synchronised to the EK80 with a ping frequency between 1 and 2.5 seconds. Please see the voyage computing and electronics report for more details regarding operation. This dataset was processed and then archived within the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart.

This record describes sub bottom profiler data collected on RV Investigator voyage IN2024_V01, 'Multidisciplinary Investigations of the Southern Ocean' which departed Hobart on 05/01/2024 and returned to Fremantle on 05/03/2024. The Kongsberg SBP120 (sub bottom profiler) was used to acquire data containing the specular reflections at different sediment interfaces below the seafloor from Hobart, along the Antarctic ice edge to Fremantle. The SBP120 provides a 3° by 3° angular resolution. The echosounder's frequency sweep range is from 2.5 to 7 kHz. The SBP120 was logged continuously for the extent of the voyage. Data are stored in *.raw and *.seg formats at CSIRO. There are 775 files totalling 29.8 GB of raw data in this dataset. The segy format data had a real time processing stream applied, which applies gain, a gain correction, matched filter with replica shaping, an attribute calculation for instantaneous amplitude and time variable gain. 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 XBT data collected on RV Investigator voyage IN2024_V01, 'Multidisciplinary Investigations of the Southern Ocean' which departed Hobart on 05/01/2024 and returned to Fremantle on 05/03/2024. A total of 109 XBT casts were conducted over the duration of this voyage. Data are stored in netCDF files at CSIRO. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request.