NON CLASSIFIÉ / UNCLASSIFIED

Hello to the QGIS user's community,

I'm a planetary scientist working for the Canadian Space Agency who is working 
with lunar south pole data. I'm struggling with an issue when running a simple 
multiplication raster calculation that I've included below (sorry for vague 
layer names, data is not public):

"Layer1" * "Layer2" * "Layer3" * "Layer4" * "Layer5" * "Layer6"

The output raster is set to the spatial resolution of the highest resolution 
layer, as I'm trying to gather contextual data from coarser datasets at very 
specific locations.

Most cells are calculated correctly, but many cells (<10-20%) are miscalculated 
to the tune of 10-30% of the expected value (sometime values are calculated 
lower than they should be, sometimes higher. Even when the highest spatial 
resolution cell is fully contained within a single cell in all other layers (no 
overlapping cell boundaries that might lead to different resampling values 
under a nearest neighbour protocol), the calculated value can still be 
incorrect.

I'm running QGIS 3.44.7, my system is using an i7-1265U with 32 gb of ram. The 
rasters are large, 5000x5000 cell 32-bit float Geotiffs. All are using the same 
coordinate system (ESRI:103878 - Moon_2000_South_Pole_Stereographic).

I've exported the input layers so I can run the same calculation in ArcPro, and 
the cells are all calculated correctly. Not sure if that helps narrow down the 
issue.

Cheers,
James

_______________________________________________
QGIS-User mailing list
[email protected]
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Reply via email to