I need to get an area of different polygons at continental scale (like third of Africa etc.). Usual functions like
rgeos::gArea work only in the projection units.
- Is there any function which works correctly in real square meters on the geoid surface? I.e. real, geodetic area?
- If not, what projection should I use to get the least distortion?
I need to measure 6 really huge areas (like third of Africa), so UTM or national projections are out of question.
Can I use a single one projection that has minimal distortion area-wise across the whole Africa?
Right now I am thinking of Mercator projection used by google maps (EPSG:3857), but I am not really sure.