Advanced underground homing system, apparatus and method

In a system including a boring tool that is moved by a drill string using a drill rig that selectively extends the drill string to the boring tool to form an underground bore such that the drill string is characterized by a drill string length which is determinable, a homing apparatus comprising:

• a transmitter, supported by the boring tool, for transmitting a time varying dipole field as a homing field and including a pitch sensor for detecting a pitch orientation of the boring tool;
• a receiver that is positionable at least proximate to a target location for detecting the homing field to produce a set of flux measurements;
• a processor that is configured to generate a vertical homing command and a horizontal homing command by combining the detected pitch orientation and the set of flux measurements with a determined length of the drill string and the processor is further configured for generating the vertical homing command at a particular accuracy that is more accurate than another accuracy of the horizontal homing command for use in controlling depth in directing the boring tool to said target location;
• and
• a display for displaying the vertical homing command and the horizontal homing command for guiding the boring tool to the target location.