RV Investigator Voyage IN2018_C01 EM2040c Multibeam Echosounder Data

This record describes multibeam echosounder data collected on RV Investigator voyage IN2018_C01, 'RAN Hydrographic Survey' which departed Hobart on the 28th May 2018 and returned to Hobart on the 8th June 2018. The overall focus for this survey was to conduct a modern survey in the primary shipping route through Bass Strait and to To facilitate safe navigation for international and coastal shipping. The Kongsberg EM2040c multibeam echosounder (dual transceivers) was used to acquire seafloor bathymetry and backscatter information (and watercolumn backscatter) near Wilson's Promontory in Bass Strait and during the transit from and to Hobart. The EM2040c provides a 1.3° by 1.3° transmit and receive angular resolution respectively. The echosounder's nominal frequency was 300 kHz and it was operated in dual swath mode. Data are stored in .all raw format for bathymetry and backscatter and .wcd format for watercolumn backscatter at CSIRO. There are 361 files totalling 60.1GB of raw .all data, and 243 files totalling 391 GB of raw .wcd in the 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. 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. The raw data is offline but is available on request.