May 2021
Esri Australia has been working with Esri and ICSM to ensure that the ArcGIS system can support clients migration from the GDA94 static datum to GDA2020 static datum. The ArcGIS system now fully supports data transformations via 7-parameter similarity transformation, or NTv2.0 transformation Grids.
As a result we are now seeing many clients migrate their authoritative datasets to GDA2020 and requiring all delivered data is in this same static datum. State and national governments are now delivering foundational open datasets in GDA2020 as well
In parallel to this migration we are also seeing more clients taking up WebGIS and delivering data via web services instead of shipping datasets or producing PDF’s. This is enabling a greater uptake web and mobile GIS, providing better informed field operators and getting live data in the hands of people who need it as they need it.
These two waves of change have presented a significant challenge. While transformations existed between WGS84 & GDA94 and GDA94 & GDA2020, there existed no direct path from GDA2020 to WGS84. If you wanted to place GDA2020 data into WebGIS you had to transform you data back through GDA94 to WGS84. Effectively moving the data back to its old location prior to publishing. Many clients asked why????
It has been termed the WGS84 Projection dilemma. So what’s changing?
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