KB10585 - Does the DK support the Australian GDA 94 (Griding Datum of Australia 94) geographic coordinate system?

Prior to the DK v.8 final release version, the GDA 94 coordinate system is not directly supported as a simple selection item, but support for GDA 94 can be easily added to a DK application with just a single line of code, as follows:

; DatumList.AddEx( gisDatumTypeDATUM7, 'GDA94', 'AUSTRALIAN GEODETIC 1994',
; ; ; 'GDA94',
; ; ; 'RF', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
;) ;

For the DK-ActiveX version, the datum list can be defined as:
; ;Dim DatumList as New XGIS_DatumList

The enhanced coordinate system support in the DK 8 final release will support GDA 94, as well as approximately 1,800 other defined geographic coordinate systems in use around the world, as simple selection items. Then even the single line of code will not be required.

Incidentally, as of December 2004 (prior to the DK 8 final release), the DK directly supports the following three coordinate systems relating to Australia:

- AUA, AUSTRALIAN GEODETIC 1966
- AUG, AUSTRALIAN GEODETIC 1984
- WGS, World Geodetic System 1984

The GDA 94 coordinate system is practically the same as the WGS84. The precision differences between the GDA94 and WGS84 are sub-meter, and sometimes a matter of only a few centimeters, i.e., within standard GIS tolerances.

For more information about this issue refer to the discussion at: http://www.icsm.gov.au/icsm/gda/wgs84fact.pdf