I want to extract a world map to the Great Lake region. The original data doesn't have a projection. (the original data is fromhttp://www.uni-klu.ac.at/socec/inhalt/1191.htm). They seem don't have metadata either.
So I defined a project WGS_1984_World_Mercator to it and also reprojected my mask data also to WGS_1984_World_Mercator . But the two data sets don't have overlapping areas. When I tried to extract the world map with the mask using extract by mask tool, it showed me "invalid output extent". I think it may because I defined the wrong projection. But I don't know the original projection. It may also caused by other reasons that I'm not aware of. Can anyone point a way to me? Thank you very much!!!