u/Gwindip

▲ 6 r/QGIS

Reprojection Help

I'm working with ETOPO 2022 data downloaded from the NOAA website and trying to reproject it from EPSG:4326 to EPSG:3031 (Antarctic Polar Stereographic). I'm not having any luck, and I'm hoping someone can help me figure out what I'm doing wrong.

I've imported the .tif file as a raster layer. When I change the coordinate reference system using Layer > Set CRS of Layer > EPSG:3031, the data appears to render just fine in the viewport, but if I instead try to reproject the data using Raster > Projections > Warp (Reproject), the resulting data seems to be filled with a Nodata value, or is corrupted in some way. It doesn't show up in the viewport when opened as a layer, and when saving as a .png file it's completely black. If I try to warp and save the output as another .tif file, I get an error saying `Too many points failed to transform, unable to compute output bounds.` and `Unable to compute source region for output window.`

I've tried this same method using a user defined CRS using the proj string `+proj=stere +lat_0=-90 +lon_0=0 +x_0=0 +y_0=0 +a=6371000 +b=6371000 +units=m +no_defs`, and it works, but the resulting data is way too compressed at the south pole to be useful. Adding `+k_0=*` or '+k=*` to the end doesn't affect the scale of the output either. I'm not familiar with proj strings, so I'm not sure if there's a tag I'm missing or misusing here.

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u/Gwindip — 15 days ago