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XYZ multibeam bathymetric grids of the Bremer Sub-Basin

Note: This metadata describes the dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2.


Dataset citation

ANZLIC unique identifier: ANZCW0703015558

Title: XYZ multibeam bathymetric grids of the Bremer Sub-Basin


Custodian

Custodian: Geoscience Australia

Jurisdiction: Australia


Description

Abstract:

The compilation and processing of GA's bathymetric data in the Bremer region was produced following a request by an external client in August 2011.

This data was acquired by three research vessels, the N/O L'Atalante from IFREMER, the R.V. Marion Dufresne from IPEV and the R.V. Southern Surveyor from CSIRO.

The Bremer Sub-basin was divided into two grids:

a- Bremer1 grid and extends from Longitude 118? to 120? East, and Latitude -34? to -36? South WGS UTM 50

b- Bremer2 grid and extends from Longitude 120? to 121?.30 East and Latitude -34? to -36? South, WGS UTM 51

The Bremer Sub-basin lies between Albany and Esperance in Southern Western Australia. The Bremer Sub-basin referred to previously as the Albany Sub-Basin of the Bremer Basin, and extends over an area of 11,500Km2 in water depth ranging from 100 to 4600meters. The Sub-basin is a frontier region for petroleum exploration as few wells have been drilled.

Under the Australian government's Petroleum initiative Geoscience Australia conducted a study of the geology and petroleum potential of the Bremer Sub-Basin. The bathymetric study (GA-0265_Bremer Basin SS03/2004) started the8th of February 2004 and ended on the 10th of March 2004, onboard the RV Southern Surveyor using a Multibeam swath system EM300 (30kHz). The GA-0265 Bremer survey consists most of the bathymetric data acquired in the Sub-basin and the depth ranges from 100m to a depth of 4000meters.

A total of 11,128.5 sail Km of swath data was discovered in Geoscience Australia's data holding, that produced the following:

1- XYZ ASCII grid for Bremer1, 50m resolution (to accommodate the swath acquisition systems EM300 (30 kHz ) at the different depths) projected in Easting and Northing UTM50, WGS84.

2- XYZ ASCII grid for Bremer1, 100m resolution (to accommodate the swath acquisition systems EM120 of the N.O. L'Atalante and TSM5256 of the RV Marion Dufresne (12 kHz) at the different depths) projected in Easting and Northing UTM50, WGS84.

3- XYZ ASCII grid for Bremer2, 50m resolution (to accommodate the swath acquisition systems EM300 (30 kHz ) at the different depths) projected in Easting and Northing UTM51, WGS84.

4- XYZ ASCII grid for Bremer2, 100m resolution (to accommodate the swath acquisition systems EM120 of the N.O. L'Atalante and TSM5256 of the RV Marion Dufresne (12 kHz) at the different depths) projected in Easting and Northing UTM51, WGS84.

5- ESRI arc info grid for Bremer1, 50m resolution, projected in Easting and Northing UTM50, WGS84.

6- ESRI arc info grid for Bremer1, 100m resolution, projected in Easting and Northing UTM50, WGS84

7- ESRI arc info grid for Bremer2, 50m resolution, projected in Easting and Northing UTM51, WGS84.

8- ESRI arc info grid for Bremer2, 100m resolution, projected in Easting and Northing UTM51, WGS84.

9- Georeferenced colour tif images shaded with sun azimuth 45 degrees for Bremer1, 50m resolution.

10- Georeferenced colour tif images shaded with sun azimuth 45 degrees for Bremer1, 100m resolution.

11- Georeferenced colour tif images shaded with sun azimuth 45 degrees for Bremer2, 50m resolution.

12- Georeferenced colour tif images shaded with sun azimuth 45 degrees for Bremer2, 100m resolution.

13- Geotif of the entire area with a depth legend to go with the images.

ANZLIC search words:

  • GEOSCIENCES Mapping
  • GEOSCIENCES Geomorphology Mapping
  • MARINE Biodiversity

Spatial domain:

locality map

Geographic extent name: AUSTRALIA EXCLUDING EXTERNAL TERRITORIES - AUS - Australia - Australia

Geographic extent polygon: 117.9 -33.98, 121.52 -33.98, 121.52 -35.99, 117.9 -35.99, 117.9 -33.98,

Note: The format for each Geographic extent name is: Name - Identifier - Category - Jurisdiction (as appropriate) See GEN Register

Geographic bounding box:
North bounding latitude: -33.98 °
South bounding latitude: -35.99 °
East bounding longitude: 121.52 °
West bounding longitude: 117.9 °

Data currency

Beginning date: 1994-04-03

Ending date: 2010-08-18


Dataset status

Progress: In Progress

Maintenance and update frequency: Not Known


Access

Stored data format:
DIGITAL - ArcGIS-grid ArcInfo grid Universal Transverse Mercator (UTM) WGS84
DIGITAL - tif Tagged Image File Format (TIFF) - including GeoTIFF Universal Transverse Mercator (UTM) WGS84
DIGITAL - comma_delimited Ascii file Universal Transverse Mercator (UTM) WGS84
Available format type:
DIGITAL - comma_delimited Ascii file Universal Transverse Mercator (UTM) WGS84
DIGITAL - ArcGIS-grid ArcInfo grid Universal Transverse Mercator (UTM) WGS84
DIGITAL - tif Tagged Image File Format (TIFF) - including GeoTIFF Universal Transverse Mercator (UTM) WGS84

Access constraints:

This data is released under the Creative Common Attribution 3.0 Australia Licence.

The bathymetry grids are not to be used for any navigational puprposes.

Free Data Download

Data quality

Lineage:

The data was acquired onboard three research vessels through twelve surveys as following:

# Survey Name Vessel Name Multibeam System Institution Start Date End Date Start Port End Port

1 GA-0157_Adedav N/O Latalante EM120D (12 kHz) EM950 (95kHz) GA/IFREMER 3/04/1994 15/04/1994 Adelaide SW Timor

2 GA-0208_Margau (MD110) RV Marion Dufresne TSM 5256 (12 kHz) GA/IPEV 29/04/1998 29/05/1998 Fremantle Fremantle

3 GA-0236_Auscan1 (MD130) RV Marion Dufresne TSM 5256 (12 kHz) GA/IPEV 23/01/2003 16/02/2003 Fremantle Hobart

4 GA-0245_Auscan2 (MD131) RV Marion Dufresne TSM 5256 (12 kHz) GA/IPEV 18/02/2003 4/03/2003 Hobart Fremantle

5 GA-0265_Bremer (SS03/2004)RV Southern Surveyor EM300 (30 kHz) CSIRO 9/02/2004 9/03/2004 Fremantle Hobart

6 GA-0296_WA Bio1(SS07/2005)RV Southern Surveyor EM300 (30 kHz) CSIRO 21/07/2005 15/08/2005 Dampier Fremantle

7 GA-2390 WA Bio2 (SS10/2005)RV Southern Surveyor EM300 (30 kHz) CSIRO 17/11/2005 14/12/2005 Fremantle Dampier

8 GA-2396_Ausfair Transit (VT82)RV Marion Dufresne TSM 5256 (12 kHz)GA/IPEV 27/02/2006 6/03/2006 Sydney Albany

9 GA-2400_Leuwin (SS04/2006) RV Southern Surveyor EM300 (30 kHz) CSIRO 9/04/2006 30/04/2006 Esperance Fremantle

10 GA-2433_Hobart_Fremantle(SST03/2007) RV Southern Surveyor EM300 (30 kHz) CSIRO 30/04/2007 9/05/2007 Hobart Fremantle

11 GA-4304_Hobart_Broome Transit (SST01/2010) RV Southern Surveyor EM300 (30 kHz) CSIRO 29/03/2010 13/04/2010 Hobart Broome

12 GA-4324_Fremantle-Hobart Transit (SST02/2010) RV Southern Surveyor EM300 (30 kHz) CSIRO 10/08/2010 18/08/2010 Fremantle Hobart

The data was converted into the bathymetric processing software CARIS HIPS & SIPS using the following procedures:

1- A vessel configuration file was created for RV Southern_Surveyor, NO_Latalante and RV_Marion Dufrene, where the co-ordinates of the motion sensor and DGPS antenna and patch test offsets were recorded.

2- The raw swath sonar data, in raw.all format for RV_Southern_Surveyor, mb75 for L?Atalante and Marion Dufresne, for each line was then imported into the project and the vessel information assigned to the data.

3- The motion sensor, DGPS and heading data were then cleaned using a filter that averaged adjacent data to remove artefacts.

4- 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.

5- Then a new blank field area was defined that specified the geographic area of study and the co-ordinate system used. Two grids were created for the Bremer sub-basin, Bremer1 and Bremer2. The co-ordinates for the study areas were WGS84 UTM-50S for Bremer1 sub basin, and WGS84UTM51 for Bremer2 sub-basin.

6- 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.

7- 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.

8- The processed data was finally exported as final processed data in ASCII XYZ file format with header information, exported as Easting and Northing and negative depth, projected in UTM50 and 51 and WGS84 as datum.

9- 8 ESRI Arc Info grids were created from those bathymetric ASCII XYZ grids.

10- Geotifs were created for those grids at 50 and 100m resolution and an addition geotif of the whole Bremer basin with a depth legend.

Positional accuracy:

Visual assessment of the grids indicates that its logical consistency is good.

The RV Southern Surveyor used a DGPS and four antennae connected to GPS receiver with an accuracy of 2 to 3m.

Attribute accuracy:

High quality swath bathymetric data that form an aerial coverage exists, overlapping swaths and speed of sound corrections show that the data are quite accurate. Some transit swath data also have speed of sound corrections applied and are assumed to be highly accurate. Other transit swath surveys have utilized a nominal speed of sound of 1500m/s and are not as accurate.

Logical Consistency:

Visual assessement of the grids indicates that its logical consistency is good.

Each of the area input dataset was examined in detail and edited where necessary. Bremer sub-basin bathymetric data was compiled from different intersected generic surveys and those overlapping generic surveys were corrected as well as GA's bathy database.

Completeness:

All of GA's multibeam bathymetric data holding was used to produce the grids.


Contact information

Contact organisation: Commonwealth of Australia (Geoscience Australia) (GA)
Contact position: Manager Client Services
Mail address: Cnr Jerrabomberra Ave and Hindmarsh Dr
Mail address: GPO Box 378
Locality: Canberra
State: ACT
Country: Australia
Postcode: 2601
Telephone: 02 6249 9966
Facsimile: 02 6249 9960
Electronic mail address: sales@ga.gov.au

Metadata information

Metadata date: 2013-03-08


Additional metadata

Metadata reference XHTML: http://www.ga.gov.au/meta/ANZCW0703015558.html

Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703015558.xml

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Authors:Spinoccia, M.
SPATIAL INFORMATION FOR THE NATION