GDA2020 and Web Mercator

Discussion created by MChilcott on May 9, 2018
Latest reply on Apr 29, 2019 by liklm01

Hi Peoples,


Environment : ArcGIS Pro 2.1


If our data is in GDA2020 and we transform to Web Mercator, the software first does a datum transformation to GDA94, and then to Web Mercator.  The Geographic Transformation is chosen for me, and I cannot alter it, nor can I delete it – as shown below.


Project Geographic Transform


This is what is occurring:

  • GDA_1994_To_GDA2020_1
    • A datum transformation to GDA94
  • GDA_1994_To_WGS_1984
    • NULL datum transformation to WGS84


Effectively– this is not the GDA2020 realization of web Mercator - It transformed to GDA94 first.  It is the GDA94 realization of Web Mercator.


Are other people aware of this?