1. An apparatus for determining the location of a digging implement at a work site, comprising: an undercarriage; a car body rotatably connected to said undercarriage; a boom connected to said car body; a stick connected to said boom; a work implement connected to said stick; means for rotating said car body; and a positioning system including a receiver connected to said stick and a processing means for determining the location of said receiver in three dimensional space at a plurality of points as said car body is rotated and for determining the location and orientation of said work implement in response to the location of said plurality of points.