This record describes multibeam echosounder data collected on the RV Investigator voyage IN2021_E04, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objective for this voyage were testing Seismic Systems. The voyage departed Hobart PW04 on the 15/12/2021 and returned to Hobart PW04 on the 20/12/2021. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter in the region of South East Tasmania. 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 63 files totalling 87.2 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. Tide corrections were applied to the processed data using RTK/GPS height and the EGM2008 geoid model in Caris. 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 sound velocity profile data collected on the RV Investigator voyage IN2021_E04, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objective for this voyage were testing Seismic Systems. The voyage departed Hobart PW04 on the 15/12/2021 and returned to Hobart PW04 on the 20/12/2021. A total of 12 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 scientific split-beam echosounder data collected on the RV Investigator voyage IN2021_E04, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objective for this voyage were testing Seismic Systems. The voyage departed Hobart PW04 on the 15/12/2021 and returned to Hobart PW04 on the 20/12/2021. The Simrad EK60 split beam echosounders for18kHz and Simrad EK80 split beam echosounders for 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m, in the region of South East Tasmania. All frequencies were logged continuously for the extent of the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 210 files totalling 10.1 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 sub bottom data collected on the RV Investigator voyage IN2021_E04, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objective for this voyage were testing Seismic Systems. The voyage departed Hobart PW04 on the 15/12/2021 and returned to Hobart PW04 on the 20/12/2021. The Kongsberg SBP120 (sub bottom profiler) was used to acquire data containing the specular reflections at different sediment interfaces below the seafloor. 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 (301 files 5.07 GB) raw and *.seg (146 files 2.53 GB) segy formats at CSIRO. 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 multibeam echosounder data collected on the RV Investigator voyage IN2021_E04, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objective for this voyage were testing Seismic Systems. The voyage departed Hobart PW04 on the 15/12/2021 and returned to Hobart PW04 on the 20/12/2021. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter in the region of South East Tasmania. 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 144 files totalling 12.04 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 applied to the processed data using RTK/GPS height and the EGM2008 geoid model in Caris. 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 gravity data collected on the RV Investigator voyage IN2021_E04, to calibrate and commission new, upgraded and existing critical equipment (with sea trials and personnel training) onboard RV Investigator for upcoming voyages in the 2021 schedule and beyond. The primary objective for this voyage were testing Seismic Systems. The voyage departed Hobart PW04 on the 15/12/2021 and returned to Hobart PW04 on the 20/12/2021. The gravity meter instrument is a MicroG Lacoste Air-Sea II. Data are stored in .ENV and .DAT data files at CSIRO. There are 14 files totalling 99.8 MB of raw data in this dataset. No wharf tie was performed. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report.

This record describes the Acoustic Doppler Current Profiler (ADCP) data collected from the Marine National Facility RV Investigator voyage IN2021_E04, titled "Trials & Calibrations." The voyage took place between December 15, 2021 and December 20, 2021 (AEST), departing from Hobart and returning to Hobart. Data was collected during IN2021_E04 for sections of the voyage. Data was collected using UHDAS and post-processed using CODAS. The RDI Ocean Surveyor 150kHz ADCP (os150) was run in broadband with 4m bins from the start of the voyage, while in relatively shallow water, from 2021-12-14 22:12Z. The OS150 was turned off at 2021-12-15 21:17Z to avoid interference with other sounders data that were being collected. From 2021-12-16 10:50Z both the os150 and the RDI Ocean Surveyor 75kHz ADCP (os75) were run in narrowband with 8m bins. The os75 was switch off at 2021-12-19 21:10Z as the vessel entered shallower water. The os150 was switched off at the end of the voyage at 2021-12-19 12:45Z. Internal triggering was used. The drop keel was ‘flush with the gondola’ at 1.19m below the waterline for the duration of the voyage. This dataset was processed (quality-controlled), and then archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC).

This record describes the End of Voyage (EOV) data archive from the Marine National Facility (MNF) RV Investigator voyage IN2021_E04, titled "Trials & Calibrations." The voyage took place between December 15, 2021 and December 20, 2021 (AEST), departing from Hobart and returning to Hobart. For further information please refer to the voyage documentation links. Instruments used and data collected include: Regular measurements: Acoustic Doppler Current Profiler (ADCP; 75, 150 KHz ), Greenhouse Gas Analysers (Picarro), Cloud Condensation Nuclei counter (CCN), Disdrometer, Radon sensor, Scanning Mobility Particle Sizers (SMPS), Fisheries Echosounder (EK80), Multibeam Echosounder (EM710, EM122), Sub-bottom Profiler (SBP120), GPS Positioning System, Doppler Velocity Log, Thermosalinographs (TSG), Fluorometer, Oxygen Optode, pCO2, Gravimeter, Multiangle Absorption Photometer (MAAP), Ozone Sensor, Nephelometer, Atmospheric Temperature, Humidity, Pressure, Wind and Rain sensors, Photosynthetically Active Radiation (PAR) sensor, Precision Infrared Radiometer (PIR), Precision Spectral Pyranometer (PSP), Starboard and Portside Radiometers, Air Sampler, Weather Radar. Voyage-specific measurements: Autonomous Surface Vehicle CO2 sensor (ASVCO2), Hydrophones, Seismic, Triaxus. The archive for the IN2021_E04 EOV raw data is curated by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart, with a permanent archive at the CSIRO Data Access Portal (DAP, https://data.csiro.au/dap/), providing access to voyage participants and processors of the data collected on the voyage. All voyage documentation is available electronically to MNF support via the local network. Access to voyage documentation for non-CSIRO participants can be made via NCMI_DataLibrarians@csiro.au.