RV Investigator Voyage IN2019_V06 EM122 Multibeam Echosounder Data

Updated: 2020-01-20

This record describes multibeam echosounder data collected on RV Investigator voyage IN2019_V06, titled 'Tropical observations of atmospheric convection, biogenic emissions, ocean mixing, and processes generating intra-seasonal SST variability' which departed Darwin on the 19th of October 2019 and returned to Darwin on the 17th of December 2019 ,consisting of two legs. Leg 1 - Darwin, 20:00, 19 October 2019 to Darwin, 19:00, 10 November 2019 Leg 2 - Darwin, 20:00, 11 November 2019 to Darwin, 08:00, 17 December 2019 The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn around the Northwest Shelf station (121.5 E, 14 S) for Leg 1, however was not used in Leg 2 due to shallow water (<100m). 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 467 files totalling 36 GB of raw data in this dataset, covering approximately 1,779 nautical miles. 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.