NSW Continental Slopes Survey (GA-2413/SS10/2006) - Bathymetry grids

Full description

The NSW Continental Slopes survey GA-2413, SS10/2006 was acquired by Geoscience australia onboard the RV Southern Surveyor from the 12th of October to the 25th of October 2006. The geographical range stretched from Jervis bay in the South to Port Stephens in the North. The aim was to assess the physical nature of the NSW continental slope, improve our understanding of the surface and subsurface structure of the continental slope and to investigate the history of sediment movement along the continental slope.

This dataset is not to be used for navigational purposes.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: This multibeam bathymetry was acquired by the following survey: # Survey Name Vessel Name Multibeam System Institution Start Date End Date Start Port End Port 1 GA-2413 NSW Slopes SS10/2006 RV_Southern Surveyor EM300 GA 12/10/2006 25/10/2006 Sydney Sydney The NSW Continental Slopes survey GA-2413, SS10/2006 was acquired by Geoscience australia onboard the RV Southern Surveyor from the 12th of October to the 25th of October 2006. The geographical range stretched from Jervis bay in the South to Port Stephens in the North. The aim was to assess the physical nature of the NSW continental slope, improve our understanding of the surface and subsurface structure of the continental slope and to investigate the history of sediment movement along the continental slope. This dataset was acquired and processed onboard by Andrea and Michele Spinoccia and further processing was done in the office by Michele Spinoccia. The bathymetry data was gridded at a 50m resolution grid and was projected into WGS84 UTM zone 56S. Swath data was processed through Caris HIPS/SIPS version 7.1.2 1. First a vessel configuration file was created where the co-ordinates of the motion sensor and DGPS antenna and patch test offsets were recorded. 2. A new project was then created and the vessel configuration file was attached to the project file. 3. The raw swath sonar data, in raw.all format, for each line was then imported into the project and the vessel information assigned to the data. 4. The motion sensor, DGPS and heading data were then cleaned using a filter that averaged adjacent data to remove artifacts. 5. Different sound velocity profiles data for each block were attached to the corresponding raw swath sonar data files to correct the depths for changes in the speed of sound through the water column. 6. Then a new blank field area was defined that specified the geographic area of study and the co-ordinate system used. The co-ordinates for the study areas were WGS84 UTM-56S. 7. The data was cleaned by applying several filters that removed any remaining spikes in the bathymetry data using user defined threshold values. A visual inspection of the data for each line was then undertaken where artifacts and noisy data not removed by the filtering process were removed manually using Swath and subset editors modules of the Caris HIPS/SIPS software. 8. All the data for each bathymetric, motion sensor, DGPS, heading, tide and sound velocity profile data were merged to produce the final processed data file. A weighted grid of the processed data was then created for each Block. In GA the tide was applied to the grid to correct for tidal variations and velocity corrections were performed to correct for different artifacts and mismatches. 9. The processed data was finally exported as grids soundings or false colored images for presentation and reporting and as final processed data in in ASCII XYZ as well as geotif formats of 50m resolution. 10- Using CARIS Base editor 4.0 the grids were exported as ESRI ASCII grid, then imported into ARC catalogue/info to create a raster file for the entire survey.