I'm working on a project for a client which is migrating data from an Oracle database to an ESRI Geodatabase. When data for this project was initially captured over 15 years ago, the coordinate system used was either UTM Zone 56 South or GDA94 MGA Zone 56 because much of the data was for South East Queensland, Australia. However, as the company grew, they continued to add data further west and maintained the same coordinate system. The data now extends as far west as Darwin, Australia which is in Zone 52.
My instinct is to reproject the data to GDA94 Lat/Long. However, I'm not sure if this will make things worse or better.
I have two questions:
- How much error is in the data which is 4 zones out (i.e. in metres/kilometres)?
- Will I introduce more error by reprojecting the data to GDA94 Lat/Long? Or is this the right approach?