The present invention provides operators the ability to follow a
predetermined path and achieve desired digging depth by watching steering
and elevation indicators of just one system. The indicators are activated
by data derived from the interception of signals generated by a single
laser transmitter and a receiver array mounted on the machine. The system
according to the present invention uses the multiple, tilted fan beams
provided by the laser transmitter to calculate elevation angle and
azimuth of the tool carried by machine.