I have received a set of local transformation parameters from my surveyor to go from WGS84/UTM36S to ARC1950/UTM36S (See picture below)
The way QGIS does the transformation is not the best. I am working in Malawi and the default transformation parameters give misplacements of 20 to 40 m. This is why I ask a very reliable local surveyor to provide the local parameters for the area of interest.
What is the proper way to write a proj line to introduce these parameters into QGIS?
I was trying:
+proj=utm +zone=36 +south +datum=WGS84 +units=m +no_defs +x=249.7578 +y=2.8706 +z=203.0842 +rx=-14.90782 +ry=-6.25396 +rz=0.20011 +s=-7.3003
But it does not seem to work.