Venus as in the planet Venus? Just checking.

So regardless of what the base project coordinate system is set to, if the incoming data are in a different coordinate system QGIS will need to apply an "on the fly" transformation to get them to match up visually in the projects map view. You said these are all in the same projection, but not as far QGIS is concerned, otherwise it would not be trying to use a transformation. It is possible for some standard coordinate systems to be read in by QGIS as a "custom CRS" instead. If these different layers all need to work together in QGIS then I would open each individually into a fresh QGIS project and reproject them one at a time into the known QGIS version of the CRS that's needed. Then try to open them together to see if the transformation issue has been resolved.

Good luck!
David



David Medeiros

Geospatial Reference & Instruction Specialist

Stanford Geospatial Center

650.561.5294

mapbliss.com


SGC website: gis.stanford.edu

GIS cartography: bit.ly/giscart<http://bit.ly/giscart><http://bit.ly/giscart>

GIS email list: bit.ly/GISlist


________________________________
From: Maps-L: Map Librarians, etc. <[log in to unmask]> on behalf of Diaz, Tony A. <[log in to unmask]>
Sent: Friday, November 10, 2023 9:07 AM
To: [log in to unmask] <[log in to unmask]>
Subject: QGIS projection question


Hi all, I have a student who is trying to load in a Venus global map data but when they try to align different maps with the same projection, or even change projection, they get an error (consistently)  "No transform available between XXXX and Custom CRS”.



Any ideas or resources I could point them to?





Thanks,



Tony Diaz

Caltech
Pasadena, CA