| 
Coordinate system changes
Improvements to the ACT cadastre
Changes to the ACT’s coordinate system are being made on a progressive, ongoing basis.
Use of SGC/AGC
The ACT grid is made up of three separate zones: SGC/AGC, SGC/PGC and SGC/CC. The cadastre in these zones, as well as the survey marks, is one of SGC/AGC, SGC/PGC or SGC/CC.
To improve the ACT cadastre, non-SGC/AGC zones are being converted to SGC/AGC. SGC/AGC is the latest and most rigorous system. This project is being done before considering converting the ACT cadastre to GDA94.
Geocentric Datum of Australia
The Geocentric Datum of Australia (GDA) is an Australian coordinate reference system. Australian states and territories that have been using Australian Geodetic Datum 66 (AGD66) or AGD84 Australian Map Grid are gradually moving to GDA, the coordinate set being the Map Grid of Australia.
However, ACT standard grid co-ordinates continue to be the standard for all spatial data sets throughout the ACT for the foreseeable future. Nonetheless, it is possible to convert ACT grid coordinates to Australian Map Grid and to Map Grid of Australia coordinates and vice versa.
For the ACT, migrating to GDA94 would require the conversion of three distinct coordinate systems. This would also create a proliferation of transformation parameter sets. Improvements in software dealing with geodetic coordinate systems is likely to make it more possible for the three systems to be converted to one, based on the GDA94.
Maps
Published 1:10,000 and 1:2500 series maps are available showing ACT grid, AMG and AGD geographical coordinates. In the future, these maps will be annotated to the effect that they are not on GDA94 and information will be available to show how equivalent GDA94 coordinates can be determined.
|
Was the information on this page helpful? |
|
 |
|
