I work with numerical boundary layer/weather prediction models and simulate flow over topography (Areas below 100sqkm). As an input it takes topography as raster data, e.g. 400 cells in y and 600 cells in x direction, origin is always the lower left corner with coordinate (0,0), with the topography height as raster cell value. In the simulation model, flow direction is always in positive x direction, so I need to rotate my topography data.
My topography source is a georeferenced TIFF file, so just exporting it to a raster would only allow me to simulate wind from west, with Python I managed to rotate it in 90° angle, so at least I can do 4 directions at the moment.
Is there a way to rotate the map by arbitrary angles, create rectangular excerpts and save the exerpt in raster format?