MChilcott

GDA2020 and Web Mercator

Discussion created by MChilcott on May 9, 2018
Latest reply on Jul 8, 2018 by MChilcott

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?

 

Implications?

 

Cheers,

Mark

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