Advanced Search  |  
 

Australian bathymetry and Topography, June 2005

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: ANZCW0703015036

Title: Australian bathymetry and Topography, June 2005


Custodian

Custodian: Geoscience Australia

Jurisdiction: Australia


Description

Abstract:

Geoscience Australia and the National Oceans Office carried out a joint venture project to produce a consistent, high-quality 9 arc second (0.0025 degree or ~250 m at the equator) bathymetric data grid of those parts of the Australian water column jurisdiction lying between 92E and 172E and 8S and 60S. As well as the waters adjacent to the continent of Australia and Tasmania, the area selected also covers the area of water column jurisdiction surrounding Macquarie Island, and the Australian Territories of Norfolk Island, Christmas Island, and Cocos (Keeling) Islands. The area selected does not include Australias marine jurisdiction off of the Territory of Heard and McDonald Islands and the Australian Antarctic Territory. The underlying data from which this grid is derived can only support this resolution in areas where direct bathymetric observations are sufficiently dense (e.g. where swath bathymetry data or digitised chart data exist). In areas where only track-line data exist, the grid resolution is high along-line but low perpendicular to lines. In areas where no sounding data are available, the grid is based on interpolated or indirectly observed bathymetry, and these data can only support a resolution of 2 arc minutes (2 nautical miles or ~3.7 km). The grid covers an area of approximately 41 million square kilometres. Its dimensions are 32003 x 20803 cells resulting in a file size slightly in excess of 1.3 Gb of 2-bytes integer numbers representing the bathymetric values. The grid synthesises approximately 1.7 billion observed data points. 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
  • MARINE Coasts
  • OCEANOGRAPHY Physical

Spatial domain:

locality map

Geographic extent name: AUSTRALIA EXCLUDING EXTERNAL TERRITORIES - AUS - Australia - 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: 2005-07-28


Dataset status

Progress: Complete

Maintenance and update frequency: Not Known


Access

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

Access constraints:

This material is released under the Creative Commons Attribution 3.0 Australia Licence.

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 34N - 79S, 90E - 180E, GA holds approximately 1400 surveys that collected bathymetric data. For ship-track data the typical spacing of point data along track is 25-200m, the two-dimensional spacing of points covered by swath surveys is of similar order. The coverage of ship-track surveys is widely variable, such that some points covered by grid lines are many tens of kilometres apart, whereas for swath bathymetry surveys, the areas of coverage are at relatively high density, but of very limited coverage. 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. These data, together with predicted bathymetry from satellite altimetry, have been brought together into a single data and processing system to allow the routine creation of grids with a range of specifications, from which grids and images can be created. The initial grid has a spatial resolution of 250 metres. It was resampled to 0.01 DD for CERF project as part of the national datasets.

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:

The data is in gridded format without attribute

Logical Consistency:

All the grids are checked at scale to verify that no data is incorrect, that there were no extraneous point segments, and that all values have the estimated correct bathymetric value.

Completeness:

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/ANZCW0703015036.html

Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703015036.xml

Webster, M., and Petkovic, P., 2005, Australian Bathymetry and Topography Grid. Geoscience

Australia Record 2005/12. Geoscience Australia, Canberra. 2 DVD.

Authors:Petkovic, P. Webster, M.A.
SPATIAL INFORMATION FOR THE NATION