Patent ID: 8668030

Claim:
In a system for tracking the position of a transmitter in the ground as the transmitter moves along an underground path which lies within a region, said transmitter being configured for transmitting an electromagnetic locating signal, a method for establishing an intended path for the transmitter within said region, said method comprising: a) with the transmitter at a start position, positioning at least two above ground detectors at initial fixed positions within a dipole range of said transmitter in an initial portion of said region for receiving the electromagnetic locating signal as the transmitter is later guided along an initial segment of the intended path within said dipole range of said transmitter; b) establishing coordinates of said detectors within the initial portion of said region; c) mapping the initial segment of the intended path through the initial portion of said region using said detectors; d) moving the detectors in a predetermined way to new locations within an adjacent, new portion of said region including an adjacent, new segment of said intended path; and e) without moving the transmitter from its start position, mapping the new segment of the intended path through the new portion of said region through which the transmitter will later pass after having passed through the initial portion of the region.