2011

Table Of Contents
global coordinate reference frame and is directly compatible with the Global
Positioning System (GPS).
Due to differences in the way the two datums were created, the GDA94
coordinates of a point appear to be about 200 meters northeast of the AGD
coordinates of the same point. The precise size and orientation of the difference
varies from place to place. For more technical information on the GDA, go to
http://www.icsm.gov.au/icsm/gda/
The new implementation of GDA94 and the associated
datum (page 2059)
transformations are available by using the coordinate system files supplied in
AutoCAD Map 3D.
See also:
Grid Data Files for Australia and New Zealand (page 109)
Coordinate System Files (page 113)
Overview of Grid Data Files and Datum Shift Issues (page 103)
To use the new high accuracy GDA94 datum
1 Reassign one of the following coordinate systems to your drawing:
AMG66-49-Grid through AMG66-57-Grid
AMG-49-Grid through AMG-57-Grid
MGA-48-Grid through MGA-58-Grid
ISG_54-2-Grid through ISG_56-2-Grid
SGC-Grid
VICT-Grid
LL-AGD84-Grid
For example, if you have a drawing that uses AM666-49, reassign it to
AM666-49-Grid before using GDA94.
2 Do one of the following:
To define a new coordinate system using high accuracy
datum (page
2059) transformations, use ASTRLA66-Grid and ASTRLA84-Grid.
To define a new coordinate system using the 3-Dimensional Similarity
Transformations, use ASTRLA66-7P, STRLA66-Tasm-7P,
ASTRLA66-VictNSW-7P, ASTRLA66-ACT-7P, and ASTRLA84-7P.
Creating New Coordinate Systems | 111