I am currently working with climate data projected in a rotated lat/lon grid and came across this excellent 'cookbook' by mkadunc on how to manually transform rotated lat/lon to regular lat/lon: gis.stackexchange.com/questions/10808/lon-lat-transformation
I’ve implemented the solution for transforming a rotated grid to a regular grid; however, I’m also interested in doing the opposite. My first thought was to just change the operational sign of ϑ and φ, so that the transformation will go ‘the other way around the clock’, but this doesn’t seem to work leaving me a bit stuck here. I’ve spend some hours now trying to read up on my trigonometry, but still haven’t been able to ‘reverse’ the function.
Hope you can help me out here.