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Australian bathymetry and topography grid, June 2009

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: ANZCW0703013116

Title: Australian bathymetry and topography grid, June 2009


Custodian

Custodian: Geoscience Australia

Jurisdiction: Australia


Description

Abstract:

In 2005 Geoscience Australia and the National Oceans Office undertook a joint project to produce a consistent, high-quality 9 arc second (0.0025? or ~250m at the equator) bathymetric grid for Australian waters. In 2009 a number of new datasets were included in an updated version of the grid.

The 2009 bathymetric grid of Australia has been produced to include recently acquired datasets, and solutions to issues identified in the previous version. The revised grid has the same extents as its 2005 counterpart, including the Australian water column jurisdiction lying between 92? E and 172? E, and 8? S and 60? S. The waters adjacent to the continent of Australia and Tasmania are included, as are areas surrounding Macquarie Island, and the Australian Territories of Norfolk Island, Christmas Island, and Cocos (Keeling) Islands. The area selected does not include Australia's marine jurisdiction offshore from the Territory of Heard and McDonald Islands and the Australian Antarctic Territory.

This report details the datasets and procedures used to produce the 2009 bathymetric grid of Australia. As per the 2005 grid, the 0.0025 decimal degree (dd) resolution is only supported where direct bathymetric observations are sufficiently dense (e.g. where swath bathymetry data or digitised chart data exist) (Webster and Petkovic, 2005). In areas where no sounding data are available (in waters off the Australian shelf), the grid is based on the 2 arc minute ETOPO (Smith and Sandwell, 1997) and 1 arc minute ETOPO (Amante and Eakins, 2008) satellite derived bathymetry. The topographic data (on shore data) is based on the revised Australian 0.0025dd topography grid (Geoscience Australia, 2008), the 0.0025dd NZ topography grid (Geographx, 2008) and the 90m SRTM DEM (Jarvis et al, 2008).

The final dataset has been provided in ESRI grid and ER Mapper (ers) formats. An associated shapefile has been produced so that the user can identify the input datasets that were used in the final grid.

IMPORTANT INFORMATION

This grid is not suitable for use as an aid to navigation, or to replace any products produced by the Australian Hydrographic Service. Geoscience Australia produces the 0.0025dd bathymetric grid of Australia specifically to provide regional and local broad scale context for scientific and industry projects, and public education.

The 0.0025dd grid size is, in many regions of this grid, far in excess of the optimal grid size for some of the input data used. On parts of the continental shelf it may be possible to produce grids at higher resolution, especially where LADS or multibeam surveys exist. However these surveys typically only cover small areas and hence do not warrant the production a regional scale grid at less than 0.0025dd.

There are a number of bathymetric datasets that have not been included in this grid for various reasons. Comments or queries about the data included in the grid (or excluded) can be directed to: IDEASRequests@ga.gov.au.

This grid is not suitable for use as an aid to navigation, or to replace any products produced by the Australian Hydrographic Service.

ANZLIC search words:

  • MARINE Mapping
  • MARINE Models
  • MARINE Coasts Management
  • OCEANOGRAPHY Physical Mapping

Spatial domain:

locality map

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

Geographic extent name: AUSTRALIAN EEZ - AUSTRALIAN EEZ - Ocean and Sea Regions - Australia

Geographic extent polygon: 92 -8, 172 -8, 172 -60, 92 -60, 92 -8,

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

Geographic bounding box:
North bounding latitude: -8 °
South bounding latitude: -60 °
East bounding longitude: 172 °
West bounding longitude: 92 °

Data currency

Beginning date: 2005-04-20

Ending date: 2009-06-29


Dataset status

Progress: Complete

Maintenance and update frequency: Not Known


Access

Stored data format:
DIGITAL - bil Band interleaved by line (BIL) image Geographic WGS84
DIGITAL - ArcGIS-grid ArcInfo grid Geographic WGS84
DIGITAL - ascii ASCII text Geographic WGS84
DIGITAL - ermapper ERMapper dataset file Geographic WGS84
Available format type:
DIGITAL - ascii ASCII text Geographic WGS84
DIGITAL - ermapper ERMapper dataset file Geographic WGS84
DIGITAL - ArcGIS-grid ArcInfo grid Geographic WGS84

Access constraints:

No restrictions

Free Data Download

Data quality

Lineage:

The data came from a variety of systems with differing data densities and levels of accuracy. In the geographic extents 34?N - 79?S, 90?E - 180?E, GA holds approximately 1400 surveys that collected bathymetric data.

This product documents the procedures used to construct the bathymetric grid and their associated displays. The input data were derived from a number of sources, were of variable vintages and quality. A number of approaches were required to process, check and edit the data. The availability of data also varied considerably throughout the region, effectively restricting the maximum useful resolution of the grid in areas where no soundings exist, to that of the satellite predicted bathymetry that was used as infill.

Acknowledgements:

The Digital Elevation Model (DEM) for New Zealand is based on the 250m DEM data supplied by Geographx, New Zealand (www.geographx.co.nz).

The DEM?s for Indonesian and Papua New Guinea are based on the SRTM DEM data supplied by the CGIAR Consortium (srtm.csi.cgiar.org/).

The deep ocean data (where high resolution data were not available) is based on the ETOPO1 and ETOPOV2G data supplied by the National Geophysical Data Center, US Department of Commerce (NGDC) (www.ngdc.noaa.gov/).

Positional accuracy:

The grid incorporates data from surveys acquired since 1963. Modern surveys which used GPS have a positional accuracy of 5 - 30 m depending on several factors, while earlier surveys which used dead reckoning and Transit satellite fixes had positions accurate to 50-2000 m depending upon the water depth and strength of currents. These surveys overlap in an irregular distribution. The grid cell size is 0.025 deg (close to 250m), and it is estimated that 90% of cells give depths within 1 cell of their measured position. Nominal scale: 1:10,000,000 when imaged at 300 dpi

Attribute accuracy:

All data is in gridded format

Logical Consistency:

All the grids are chanecked at scale to verify that no data is incorrect, that there were no extraneous point segments, and that all vales have the extimated correct bathymetric contour value.

Completeness:

This dataset is complete.


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/ANZCW0703013116.html

Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703013116.xml

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Authors:Whiteway, T.G.
SPATIAL INFORMATION FOR THE NATION