Bathymetry grids of SOJN05MV Survey (GA-1175)

Brief description

The SOJN05MV bathymetry survey, GA-1175 was acquired by Oregon state University onboard the Scripps Institution of Oceanography (SIO) RV Melville from the 19th of February to the 02nd of march 1997 using a SeaBeam 2000 sonar system. The bathymetry dataset was acquired while the RV Melville was transiting from Fremantle to Hobart. This dataset contains the 128m resolution, 32-bit geotiffs of the SOJN05MV survey produced from the processed SeaBeam system bathymetry data of the survey area using the CARIS HIPS and SIPS software. This dataset is published with the permission of the CEO, Geoscience Australia. Not to be used for navigational purposes. Appropriate acknowledgment must be given to both the original scientists (Christie, David) (http://www.marine-geo.org/tools/search/entry.php?id=SOJN05MV#datasets) and to the Marine Geoscience Data System (www.marine-geo.org). 

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Maintenance and Update Frequency: asNeeded

Statement: The SOJN05MV Survey, GA-1175 was acquired by Oregon State University onboard the RV Melville from the 19th of February to the 02nd of March 1997. The Chief scientist onboard was Dr. David Christie This dataset was acquired and processed onboard by Scripps Institution of Oceanography and further processing was conducted in Geoscience Australia by Michele Spinoccia, using CARIS HIPS & SIPS ver 7.1.2. For any metadata questions, please download the Metadata.txt file with the dataset. Processing: 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 artefacts. 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-50 to 55S. 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 artefacts 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 artefacts 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 geotif format at the optimum resolution the data can provide.