Abstract: The present invention relates to a program controlled apparatus for providing rapid calibration and update of sensor parameters in a push drill guidance apparatus which is remotely controllable from microprocessor circuitry. A special calibration program is set into non-volatile memory for coaction with the control processor to compute sensor parameters for storage and recall during normal programmed guidance operation.

Abstract: An electronic guidance system for a push drill that is remotely guided by the operator. The system functions to maintain continual indication as to the attitude of the drilling apparatus, i.e., pitch, roll and distance to rock formations overlying or underlying the drilled stratum, with such indication being made available to the remote operator so that he can control the progression of the drilling apparatus. The drilling apparatus utilizes an instrument package adjacent the drilling mechanism which samples pitch and roll data through accelerometer output, and which monitors the distance of the drill head from adjacent rock formations by means of gamma ray count.