1

My question relates to creating a custom CRS of the official coordinate system used in South Africa, called SACRS.

The SACRS is a projected coordinate system that must be referenced to BOTH the "Hartebeesthoek94" datum and the "Gauss Conform Coordinate System" (see help guides at the bottom of this post). I seek technical advice on creating this projected coordinate system as a custom CRS.

What should I type in the parameters box in QGIS (proj4 format)?

I am not sure if any of the following coordinate systems are already close (or similar) to the SACRS, but perhaps they are a good starting point for a custom CRS:

  • Hartebeesthoek94 / Lo25 [EPSG 2051]
  • South African CRS: HBK_NO_25 [ZANGI:ZANGI:HBKNO25]

Background information on the SACRS is available at:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=13&cad=rja&uact=8&ved=0ahUKEwizmdnHwoXSAhVpLMAKHY3CATUQFghRMAw&url=http%3A%2F%2Fwww.ngi.gov.za%2Findex.php%2Fresources%3Fdownload%3D37%3Athe-south-african-coordinate-reference-system&usg=AFQjCNFywI3HdttJQWFzPXFqtAr4leRdiQ&sig2=mGJdK_hyvRsJXU8-F6w86g

https://ace-notebook.com/An-introduction-to-coordinate-systems-in-south-africa-free-related-pdf.html

3

One feature characteristic to official SACRS is its axes definition: westing = Y, and southing = X. (+axis=wsu in Proj4 string.) This is the Hartebeesthoek94/LO25 (EPSG:2051) which you can choose.

The other one you also mentioned, ZANGI / HBKNO25 (easting = X and northing= Y) is not official. (And not registered in EPSG code). But it is still widely used. ArcGIS offers only this one.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.