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Magnetic Anomaly Grids of Australia 4th Edition, 2004

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: ANZCW0703007121

Title: Magnetic Anomaly Grids of Australia 4th Edition, 2004


Custodian

Custodian: Geoscience Australia

Jurisdiction: Australia


Description

Abstract:

These two versions of the Magnetic Anomaly Grid of Australia result from a completely new compilation of Total Magnetic Intensity (TMI) grid data. They have been produced using a new method of matching the individual survey grids and the use of independent data to help constrain long wavelengths. 680 individual grids have been matched and merged into these composite grids, with the resolution of each grid optimal for the specifications of the source survey line data. Since the Third Edition (Milligan and Tarlowski, 1999), data from many new surveys have been added, acquired mainly by the State and Territory geological surveys. It is estimated that 19 million line-kilometres of survey data were acquired to produce the grid data, 10 million line-kilometres more than for the Third Edition.

ANZLIC search words:

  • GEOSCIENCES Geophysics Mapping

Spatial domain:

locality map

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

Geographic extent polygon: 111 -9, 156 -9, 156 -45, 111 -45, 111 -9,

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

Geographic bounding box:
North bounding latitude: -9 °
South bounding latitude: -45 °
East bounding longitude: 156 °
West bounding longitude: 111 °

Data currency

Beginning date: 1950-01-01

Ending date: 2004-09-25


Dataset status

Progress: Complete

Maintenance and update frequency: Not Known


Access

Stored data format:
DIGITAL - ers ER Mapper raster dataset ER Mapper Geographic GDA94
Available format type:
DIGITAL - ers ER Mapper raster dataset ER Mapper Geographic GDA94

Access constraints:

Licence required - see GADDS download licence and licence on CDs.

Released with the agreement of the States and Territory Geological Surveys.

Order Product

Data quality

Lineage:

These two versions of the Magnetic Anomaly Grid of Australia result from a completely new compilation of Total Magnetic Intensity (TMI) grid data. They have been produced using a new method of matching the individual survey grids and the use of independent data to help constrain long wavelengths. 680 individual grids have been matched and merged into these composite grids, with the resolution of each grid optimal for the specifications of the source survey line data. Since the Third Edition (Milligan and Tarlowski, 1999), data from many new surveys have been added, acquired mainly by the State and Territory geological surveys. It is estimated that 19 million line-kilometres of survey data were acquired to produce the grid data, 10 million line-kilometres more than for the Third Edition.

Positional accuracy:

The grids are available at two resolutions: (1) a grid of airborne survey data with a pixel size of 7.2 seconds-of-arc (approx. 250 m cell size) and (2) a grid of data with a pixel size of 15 seconds-of-arc (approx. 400 m cell size)

The positional accuracy is highly variable depending on the age of the individual surveys that comprise this dataset. Prior to 1990, data were usually collected using photographic flight path recovery which has an accuracy of plus or minus 100 metres. More recent surveys were acquired using differential GPS giving accuracy better than 5 metres. Surveys acquired with a line spacing less than or equal to 400 metres usually represent these newer surveys.

Attribute accuracy:

Highly variable depending on the age of the individual surveys that comprise this dataset. Prior to 1990, survey data were acquired using proton procession magnetometers, which have an accuracy of plus or minus 0.1 to 5 nT (nano Tesla's), or fluxgate magnetometers which make relative measurements and have a precision of better than 0.1nT. Modern surveys after this time used helium or caesium magnetometers which have an accuracy of 0.1 nano Tesla's or better. Surveys acquired with a line spacing less than 400 metres usually represent these newer more accurate surveys.

Logical Consistency:

These grids were produced by stitching together grids derived from airborne geophysical surveys. The grids from adjoining individual surveys were stitched together using polynomial corrections in such a way as to minimise differences in the overlapping regions. Smaller errors are then smoothed at the join.

Completeness:

The dataset coverage is complete for the whole of continental Australia.


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/ANZCW0703007121.html

Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703007121.xml

Refer to these grids as:

Milligan, P.R. and Franklin, R. 2004.

Magnetic anomaly grids of Australia 4th edition. [Digital Dataset].

Canberra: Geoscience Australia.

Authors:Milligan, P.R. Franklin, R.
SPATIAL INFORMATION FOR THE NATION