Description
Summary:Maintenance and Update Frequency: asNeeded Statement: Original field data. Processed data are SV corrected, tide not corrected and edited using CARIS version 10.3.8 This record describes multibeam echosounder data collected on RV Investigator voyage IN2021_V01 titled: "Quantifying krill abundance for krill monitoring and management off the Australian Antarctic Territory," which departed Hobart on the 29th January 2021 and returned to Hobart on the 24th March 2021 (AEST). The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter on the transit to the survey site and also preiodically during CTD operations. 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 1864 files totalling 109.2 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. The data have been reduced to approximate Mean Sea Level (MSL) using the Earth Gravitation Model 2008 (EGM2008) 1 arc-minute grid. 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.