I was wondering if anyone would be able to tell me the difference between UTM UPS GDA94 (set on my GPS) and GDA94/MGA zone 56, the nearest equivalent I can find in ArcGIS (under Projected Coordinate Systems – National Grid – Australia).
When I import GPS coordinates (UTM UPS GDA94) into ArcGIS in an excel file and onto a GCS GDA94 dataframe, I set the projection to GDA94/MGA zone 56, and they appear in the correct place on the map.
I'm still coming to terms with different coordinate systems.
Best Answer
You may not receive definitive answers without details of your GPS system settings, but in essence they should be the same.
It is still difficult to find clear definition of MGA (Map Grid of Australia 1994), even in the website of Geoscience Australia. It goes back to older Australian Map Grid (AMG) system. Both AMG and MGA use UTM-based concept, with same projection parameters, but from the different ellipsoids.
To avoid confusion, state and federal governments decided to change those names; AGD should be replaced by GDA, and AMG by MGA.
Bottomline: please check your GPS settings. If it is UTM zone 56S based on GDA94 (ITRF92:GRS80), you would be good with GDA94/MGA zone56.