Patent ID: 7049820
Filing Date: 2006-05-23
Classification: E21B,G01V

Abstract:
1. In a system in which an inground device is moved through the ground within a region along a path, a method for establishing a location of at least a portion of said path, said method comprising: providing a portable locator; using an information generating arrangement for generating certain information including a set of positional information characterizing an inground position of the inground device relative to a locating position of the portable locator in said region, locating said information generating arrangement partially at and forming part of said inground device and partially at and forming part of said portable locator, and configuring said information generating arrangement to include a transmitter for transmitting a dipole field from the inground device and to include a receiver having less than five spaced-apart sensors at said portable locator at least for sensing said dipole field at a series of spaced-apart reference points along a reference path which reference points are associated one-for-one with a series of spaced-apart measuring locations of the inground device, as the inground device moves along the path, so that each reference point on the reference path is specifically determined by an associated one of the measuring locations; and configuring a processing arrangement for using the set of positional information that is obtained corresponding to each of the spaced-apart reference points, either as being obtained or thereafter, to establish an actual path taken by the inground device and containing the measurement locations.