LOCATING TECHNIQUE AND APPARATUS USING AN APPROXIMATED DIPOLE SIGNAL

摘要

Location determination is performed using a transmitter including an elongated generally planar loop antenna defining an elongation axis. The elongation axis is positioned along at least a portion of a path. A magnetic field is then generated which approximates a dipole field. Certain characteristics of the magnetic field are then determined at a receiving position radially displaced from the antenna elongation axis. Using the determined certain characteristics, at least one orientation parameter is established which characterizes a positional relationship between the receiving position and the antenna on the path. The magnetic field may be transmitted as a monotone single phase signal. The orientation parameter may be a radial offset and/or an angular orientation between the receiving position and the antenna on the path. The antenna of the transmitter may be inserted into a first borehole to transmit the magnetic field to a receiver inserted into a second borehole.

主权项

1. A receiver for use in an apparatus for location determination, said receiver comprising:
a receiver for detecting characteristics of an electromagnetic field that approximates a dipole signal in two dimensions as emanated from a transmission axis by measuring the electromagnetic field at a receiving position radially displaced from the transmission axis; and a processor forming part of the receiver for determining an orientation parameter which characterizes the receiving position relative to the transmission axis based on the measured electromagnetic field.