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GDA94 Terminology

Datum

Geocentric Datum of Australia (GDA)

Geographical coordinate set 1

Geocentric Datum of Australia 1994 (GDA94)

Grid coordinates 2

Map Grid of Australia 1994 (MGA94)

 

GDA94 definition

Reference Frame

ITRF92 (International Terrestrial Reference Frame 1992)

Epoch

1994.0

Ellipsoid

GRS80

Semi Major Axis (a)

6,378,137.0 m

Inverse flattening (1/f)

298.257222101

 

1 Latitude and Longitude

2 Universal Transverse Mercator, using the GRS80 ellipsoid

 

GDA Extent

Includes all the areas contained within Australia's marine jurisdiction within 200 nautical miles of Australia and its external territories, and the areas of Australia’s continental shelf beyond 200 nautical miles as confirmed by the United Nations Commission on the Limits of the Continental Shelf. The areas include Cocos (Keeling) Island, Christmas Island, Norfolk Island and Macquarie Island but excludes Heard-McDonald Island and the Australian Antarctic Territory (AAT)

 

Reference

GDA94 Technical Manual v2.4.pdf

GDA2020 Terminology

Datum

Geocentric Datum of Australia (GDA2020)

Geographical coordinate set 1

Geocentric Datum of Australia 1994 (GDA2020)

Grid coordinates 2

Map Grid of Australia 2020 (MGA2020)

 

GDA2020 definition

Reference Frame

ITRF2014 (International Terrestrial Reference Frame 2014)

Epoch

2020.0

Ellipsoid

GRS80

Semi Major Axis (a)

6,378,137.0 m

Inverse flattening (1/f)

298.257222101

 

1 Latitude and Longitude

2 Universal Transverse Mercator, using the GRS80 ellipsoid

 

GDA Extent 

The extent of the GDA2020 includes all the areas contained within Australia's marine jurisdiction (within 200 nautical miles of Australia) and its external territories, and the areas of Australia’s continental shelf beyond 200 nautical miles as confirmed by the United Nations Commission on the Limits of the Continental Shelf. The areas include Cocos (Keeling) Islands, Christmas Island, Norfolk Island and Macquarie Island but excludes Heard-McDonald Islands and the Australian Antarctic Territory (AAT) as shown in Figure 1.1. The extent of GDA2020 is the same as the extent of GDA94.

Reference

GDA2020 Technical Manual V1.5_4.pdf

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