Method and apparatus for establishing the position of a sonde in a region using a single detector

Abstract

An apparatus and method are described for tracking the position, orientation and/or guiding a sonde as it moves through the ground in a region. The sonde transmits an electromagnetic field received by one detector. The detector includes at least one antenna for measuring at least one component of the intensity of the electromagnetic field and the detector is positioned at a fixed position with the antenna at a particular orientation within the region. Certain initial conditions are determined including the particular orientation and position of the antenna associated with the detector and an initial position and orientation of the sonde. The intensity of the electromagnetic field is obtained at a second position using the detector after the sonde moves a distance to the second position. The coordinate position of the sonde is determined using the initial conditions along with the intensity measured at the second position.