Abstract: The present invention is an apparatus and method for accurately determining the position of a tool, for example an earthmoving bucket, mounted at the end of an arm which has a plurality of pivot points and is pivotally attached to the base of a machine, for example a piece of construction equipment like the platform of an excavator or other earthmoving machine. The present apparatus includes a plurality of reflectors mounted on the machine for indicating movement of the arm and the tool. Each reflector is operatively adapted for reflecting light back toward a light source. A light transceiver is mounted on the machine in a known relationship to the reflectors. The light transceiver is operatively adapted for transmitting a beam of light to illuminate each of the reflectors, thereby generating reflective light. The light transceiver detects the reflective light and the angular orientation of the reflective light it detects.