Can someone explain how the newly added Projected Australian GDA2020 GCS works in Microstation CE U11?
We have the old GDA94 GCS group, a new GDA94-7P (7 Parameter Transformation to 2020), GDA94/GSB (GDA94 to 2020 using Grid Shift files) and a plain GDA2020 GCS group. If I reproject the data from the old GDA94 to the GDA-7P or GDA95/GSB GCS settings my data moves as expected, however nothing happens if I go from the old GDA94 to the new GDA2020.
How is this supposed to work?
In order to migrate from GDA94 to GDA2020 you must first change or correct the Geographic Coordinate System from the GDA94 system, to the equivalent based on GDA94/GSB -- without reprojecting. This is a Correction from a coordinate system that used to be based on WGS84 to something that is not anymore (GDA94 used to be considered coincident to WGS84. Now it is GDA2020 that is considered coincident to WGS84 but we cannot change the definition of GDA94 after its existence).
Once that is done you can reproject to the GDA2020-based Geographic Coordinate System.
So your process will be a two-step process; 1. Correct the Geographic Coordinate System, do not reproject the data. 2. Reproject the data
Answer Verified By: Mark Shamoun
Excellent, that makes sense.
OpenRoads Designer 2021 R1 (10.10) | Microstation CE Update 16 | ProjectWise CE 3.4
Can you provide more information on how to do the reprojection part of the 2 steps? Changing the geographic coordinate system is obviously what the screenshot shows above, but having first selected 'do not reproject the data', what do you have to do to reproject the data?
The last step to reproject the data occurs when you select the system with GDA2020 details and the dialog presents you with the same two options - Correcting the data, or Reprojecting the data. You would select the 2nd choice, or "Reproject the data to the new Geographic Coordinate System".
The process actually considers three coordinate systems, and two steps:
1. The original WGS84 coordinate system
2. The intermediate GDA94 coordinate system, to correct the system
3. The final GDA94/GDA2020 coordinate system (this is the step to select "Reproject the data...")