I suspect it doesn't explicitly - provided it's got good enough positional information, it can just use all the traditional techniques of closed-loop control to get there and stay there.
How it gets the positional information isn't clear. Some sources say GPS, I'm guessing that relies on the relative error being very small and not caring about the absolute error.
How it gets the positional information isn't clear. Some sources say GPS, I'm guessing that relies on the relative error being very small and not caring about the absolute error.