Shellharbour Tharawal marine survey - bathymetry (NSWENV20171130/GA4878)

Brief description

This resource includes bathymetry data acquired during the Shellharbour Tharawal marine survey collected by the NSW government (Department of Planning and Environment – DPE) during the period 25 May – 30 November 2017 onboard the RV Bombora using DPE’s R2Sonic 2022 multibeam sonar. The Shellharbour bathymetry survey was led by Dr. Bradley Morris (DPE Coasts and Marine) as part of SeabedNSW program funded by NSW Coastal Reforms package. The purpose of the project was to 1) provide a baseline dataset and 2) map the spatial distribution of seabed types. The data will provide a better understanding of nearshore sediment distribution/transport mechanisms for improved assessment of threats/risks associated with erosion events (i.e. East Coast Lows) and changing sea levels. This dataset contains 2 x 32-bit floating point geotiff files of bathymetry (2m and 5m gridded) for the study area, derived from the processed Hypack, R2Sonic GUI, POSView, POSPac and Qimera software. A detailed report on the survey is provided in: i) AusSeabed Survey Report and ii) NSW DPE Scientific Rigor Statement NSWENV_20171130_Shellharbour_MB_ScientificRigour.pdf. This dataset is not to be used for navigational purposes. This dataset is published with the permission of the Senior Team Leader and the department’s Hydrosurveyor, Coasts and Marine Science, NSW Dept. Planning and Environment.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: While AusSeabed aims to publish data based on the requirements stated in the AusSeabed multibeam guidelines (version 1, https://australian-multibeam-guidelines.github.io), we will also publish interim products (version 0) that are currently available, but have not yet been standardised (version 1). Users should be aware that V1 products will always supersede V0 products. This dataset was produced using QPS Qimera and the AusSeabed-recommended processing methodology as follows. 1. A new QPS Qimera project was created in conjunction with existing or newly created vessel configuration file(s). 2. The raw swath sonar data files were imported to the project. G2 Marine Star provides the navigation and ellipsoid height source and is recorded in POSView and post-processed in POSPac for a Smoothed Best Estimate of Trajectory (SBET) using the Single-Base Station module. 3. The POSMV data files were imported to the project to bring in delayed heave, delayed heave RMS, ellipsoid height and ellipsoid height RMS. 4. TPU and GPS tide were computed and all data were georeferenced (merged) to AHD using the ellipsoid AusGeoid09 model. 5. An auto-resolution CUBE was generated as a reference surface for data cleaning. 6. An automated data cleaning using the surface cleaning method with the reference surface was undertaken. 7. Further manual cleaning was conducted as required after visual assessment. 8. The final grid was produced at a 2 and 5m resolution. 9. At Geoscience Australia, the received geotiff was shifted to EGM2008 using AusCoastVDT and CARIS HIPS and SIPS. 10. The final processed grids were exported as 2 x 32-bit floating point Geotiffs at 2m and 5m resolution, referenced to EGM2008.

Notes

Purpose
marine survey