mobile robot with gps
I want to build path planning with voronoi diagram. So first of all, I have to build 2D map of robot's environment and then partition their boundaries with voronoi diagram. And then i will convert this map to topological map in order to compute it's shortest path. But this resultant path also must obey traffic law. So now i am confusing with applying GPS system. If i will use GPS , i will get four dimensions (attitude , longitude , height and time).
So my question is:
1) How to convert the resultant output of GPS to 2D map?
2) Have I to need apply other sensors ( sonarsensor and camera) to get 2D map?
3) Can I use only GPS system in my mobile robot?(without sonarsensor and camera)
P.S my mobile robot is inteneded to travel in township situation but static environment. Thanks in advance.