Otway Basin bathymetry

Full description

This is a compilation of all the processed bathymetric datasets held by Geoscience Australia for the Otway Basin, extending from Cape Jaffa in South Australia to north-west Tasmania. This dataset includes multibeam echosounder and LIDAR data, and was gridded at two resolutions (50 and 128 m) based on optimal resolution for the depth range encountered.

The objective of this Otway Basin bathymetry dataset is to increase our understanding of the seafloor geomorphology of the region and provide a primary input dataset for the creation of numerous subsurface geophysical products. These include inputs to calibrated gravity and magnetic data to provide new insights to geological morphology and processes, inputs to 2D and 3D seismic processing for better subsurface imaging, inputs to velocity modelling for better time to depth conversions, and inputs to depth of burial 3D models to understand how sedimentary basins have evolved over geological time.

This dataset is published with the permission of the CEO, Geoscience Australia.
Not to be used for navigational purposes.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: This dataset was produced following a request by an internal client in April 2020. This dataset was produced using CARIS HIPS/SIPS v.7.1.2 The vertical datum is MSL while the horizontal datum is WGS84 UTM-54S. For additional metadata questions, please download the Metadata.txt file located with the dataset. Processing methodology: The LIDAR bathymetry was received as ASCII XYZ. Using CARIS generic data parser the data was converted and merged with the rest of the multibeam bathymetry using the CARIS workflow Following the CARIS HIPS/SIPS workflow, 1. A vessel configuration file was created where the co-ordinates of the motion sensor, DGPS antenna and patch test offsets were recorded. 2. A new project was created and the vessel configuration file attached to the project file. 3. The raw swath sonar data files, in raw.all format, for each line was imported into the project and the vessel information assigned to the data. Ellipsoid vertical reference system is our first preference and when not available or possible to do so a tidal zone data is the next preference to be applied to the data. 4. The motion sensor, DGPS and heading data were cleaned using a filter that averaged adjacent data to remove artefacts. 5. Sound velocity profile data for each block of data were attached to the corresponding raw swath sonar data files 6. A new blank fieldsheet area was defined that specified the geographic area of study and the co-ordinate system used. 7. The data was cleaned by applying several filters that removed any spikes in the data using user-defined threshold values. 8. Data were inspected visually for each line where artifacts and noisy data had not removed by the filtering process. 9. Remaining spikes were removed manually using the swath and subset editor modules. 10. All the data, i.e. bathymetric sounding and ancillary data, were merged to produce the final processed data file. 11. A weighted grid of the processed data was then created. 12. Independent velocity corrections were performed where velocity artefacts were observed 13. The final processed grid was exported as an ASCII XYZ and 32 bit Geotif formats at 50 and 128 m resolution.

Notes

Purpose
Client request