5

This is probably the easiest way to explain my problem:

shapefiles and raster with differing longitudinal centers

I'm not sure how to say what this problem is - is it that the shapefiles and the raster are using different longitudinal origins? (probably obvious I have a fairly loose grasp of GIS)

Regardless, what operation would I use to globe-rotate the raster so that it was aligned with the shape files? To be clear, it seems like the two data sets agree on coordinates and projection (WGS 84), it's just that the shape files all put the americas on the left and for whatever reason the topo raster puts them (and part of europe/africa) on the right.

I'm using QGIS 2.16.3 on a mac, and I'm fairly capable at installing & compiling code if needed.

4

First you could try this. A more manual approach could be:

The raster starts at Greenwich (as seen from the picture. You could device two polygons over full North-South extent, one from 0 to 180 longitude and one for the 180 degrees after that.

You use these to clip the raster to two separate rasters.

When you have cut it to two parts, move the part from 180 to 360 longitude with -360 using rasmover.

Probably this tutorial might help to merge the rasters in the end.

| improve this answer | |
  • Thanks for the suggestions - I opted for the first suggestion (gdalwarp), which took a about 9 hours to process on my macbook – Peter Hanley Nov 4 '16 at 15:29

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