Proj: Select Datum Transformations for EPSG:28992

(FOR REFERENCE, TODO: TO BE UPDATED AND TRANSLATED)

If you startup QGIS 3.8 / Zanzibar the first time to load a data in our national CRS (EPSG:28992) you are being presented with the following dialog:

projqgisveranderingen

I thought it had something todo with the fact that this OSGeo4W install maybe used the newer PROJ (6.0.1), but the About box of QGIS shows:

Compiled against PROJ5.2.0
Running against PROJ Rel. 5.2.0, September 15th, 2018

Checking my older version of QGIS I found the proj/Transformation string used there was:

Proj4: +proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +towgs84=565.2369,50.0087,465.658,-0.406857,0.350733,-1.87035,4.0812 +units=m +no_defs

The first item in the dialog looks most like it…

Strange thing is that the first item is colored GREEN, so it looks like that is the preferred or current one?

But reading the information (from PROJ), you see:

+towgs84=565.237,50.0087,465.658,-0.406857,0.350733,-1.87035,4.0812
EPSG Transformation Code: 15934
Source CRS: Amersfoort
Destination CRS: WGS 84
Remarks: Parameter values from Amersfoort to ETRS89(3) (tfm code 15739) assuming that ETRS89 is equivalent to QGS84 withing the accuracy of the transformation.
Replaces Amersfoort to WGS 84 (2) (code 1672)
Replaced by Amersfoort to WGS 84 (4) (tfm code 4833)

+towgs84=593.16,26.15,478.54,-1.3044,-0.1033,-1.1445,4.0775
EPSG Transformation Code: 1112
Source CRS: Amersfoort
Destination CRS: WGS 84
Remarks: Replaced by Amersfoort to WGS84 (2) (code 1672).

+towgs84=565.04,49.91,465.84,-0.409394,0.359705,-1.86849,4.0772
EPSG Transformation Code: 1672
Source CRS: Amersfoort
Destination CRS: WGS 84
Remarks: Parameter values from Amersfoort to ETRS89(1) (code 1751) assuming that ETRS89 is equivalent to WGS84 within the accuracy of the transformation. Replaces Amersfoort to WGS84 (1) (code 1112). Replaced by Amersfoort to WGS84 (3) (code 15934).

+towgs84=565.417,50.3319,465.552,-0.398957,0.343988,-1.8774,4.0725
EPSG Transformation Code: 4833
Source CRS: Amersfoort
Destination CRS: WGS 84
Remarks: Parameter values from Amersfoort to ETRS89(5) (tfm code 4830) assuming that ETRS89 is equivalent to WGS84 within the accuracy of the transformation.
Replaces Amersfoort to WGS84 (3) (code 15934).

So my preliminary conclusion now is: do not use the GREEN (top) one, but the last one, as that states: Replaces Amersfoort to WGS84 (3) (code 15934)..

Ok, Nyall answered my question on the mailing list.

It appears that the transformations QGIS used earlier was a little messy, and he advices lo look into QGIS with proj6. Funny thing is then you are shown just 2 options (again the first one green). I’ll have to compile projinfo to see what that gives…

screenshot-20190627104509-716x467

Anybody better information or reasoning?

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