Well, first thought is that while knowing "north" is fine, there simply is no gps system - not in Europe, not in the Hermetic system. Without a framework, there is no starting point, no grid, no reference point to start from. (This concept was suggested by , with uncertain reception, then lost to academia and re-discovered in 1350 or so - see this thread... Medieval Maps - reliable for navigation while flying? )
In short, without having a hard definition of where Paris and Rome and the English Channel are, and those relative to each other and relative to you, "You are here" is meaningless. Perhaps a direction and distance from a single, specific and known location, determined when the spell is invented (your Covenant, Durenmar, a major city, the St. Bernhard Pass, Stonehenge, whatever.)
That said, the Base seems right, if not Base 4 - location is "one natural property" imo.
With a little concentration, a mage can tell relatively where he is to earlier castings - or maybe with +1 magnitude that can be built in.