Images of the 30" Australian Bathymetric Grid (National Geoscience Dataset)  

Authors / CoAuthors

Buchanan, C. | Stanley, S. | Kilgour, B.

Abstract

Colour and greyscale images have been generated at several resolutions (pixel sizes 860m, 2km, 4km, 10km) and these are digital pictoral representations of the 30 arc second bathymetric point grid of the Australian region released in 1998 and a sub sampled version of the GEODATA NINE SECOND DEM, 1996 which is copyright, Commonwealth of Australia, AUSLIG. These images depict the continental margin morphology, and are suitable for use in diverse applications, such as resource management, oceanographic modelling and fisheries studies. The original gridded bathymetry model for the Australian continental margin was generated from 14,000,000 data points gathered from numerous data sources and compiled by Cameron Buchanan at the Australian Geological Survey Organisation, as part of the Continental Margins Program. The database is a 30-arc-second model that can display undersea features as small as 900 metres. The model has been compiled over several years from hundreds of marine surveys. It includes data acquired by industry and foreign agencies, and from over 200 days of modern deep-water seafloor swath-mapping surveys. In some areas not covered by marine surveys, it incorporates bathymetry data derived from satellite measurements. The raw ASCII data is available on CD Titled "Bathymetric 30 arc second grid of the Australian Region" (1998) from the AGSO sales centre. NOTE : This product does not contain topography.

Product Type

dataset

eCat Id

36412

Contact for the resource

Keywords

• GIS DatasetNational

( Theme )

• GIS

( Theme )

• bathymetry

( Theme )

• marine

• AU

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Retired_Internal

Publication Date

1998-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - restricted

Use - license

Status

Purpose

Maintenance Information

asNeeded

Topic Category

geoscientificInformation

Series Information

Lineage

These images are generated using ERMAPPER from 30" Australian Bathymetric Grid (1998) and a sub sampled version of the GEODATA NINE SECOND DEM, 1996 which is copyright, Commonwealth of Australia, AUSLIG . For the colour image the bathymetric and DEM data were merged and coloured using the RAINBOW colour scheme. This image was also gradient filtering (north South and East West) and illuminated from the SW to enhance topographic features.The grid was then converted into an 8bit BIL image suitable for Arcinfo/Arcview. The one band greyscale image was developed by merging the bathymetric and DEM data histogram equlised A one band greyscale image has been developed of the above as well. <p>The original gridded bathymetry model for the Australian continental margin was generated from Bathymetry data collected from various agencies and compiled and extrapolated by an algorithm developed by C. Buchanan. The number of values corresponds to a grid of 2940 by 2160 two-byte binary integer values representing all the one minute intersection points between 90 00' - 440 59' south, and 1080 00' - 1560 59' east. The geographical coordinates and water depths only were used. Compiled data were then read and applied to the model (the grid) using a nearest point (distance weighted) method. The nearest point was used because resampling of the dataset to a lower resolution would not require reintegration of raw data by the iteration process. Resampling to a higher resolution could be achieved by reintegration using the same algorithm and the result would be a more detailed model.

Parent Information

Extents

[-45.0, -8.0, 107.0, 160.0]

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Spatial Resolution

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