Patent ID: 7663371
Filing Date: 2010-02-16
Classification: E21B,G01C,G01V

Abstract:
1. In a system in which a boring tool is moved through the ground within a given region along a path while transmitting a locating signal such that the locating signal exhibits locate points at the surface of the ground, both ahead of and to the rear of the boring tool, wherein the locating signal includes a transmit axis defined within a vertical plane including the locate points and the locating signal exhibits a locate line that is accessible at the surface of the ground and is included in a locate plane which extends through the boring tool transverse to the transmit axis, a method comprising: a) measuring a local flux intensity of the locating signal for at least one above ground point to establish a flux vector at that point which is generally oriented in a horizontal plane; b) displaying an orientation of the flux vector to an operator at the above ground point in a predetermined way to, at least in part, serve in guiding the operator to at least one of the locate points; c) using steps (a) and (b) in a repeatable manner in establishing a side locating above ground point that is within a side locating region defined between a pair of planes one of which extends through each locate point generally transverse to said transmit axis; d) measuring an additional local flux intensity of the locating signal at the side locating above ground point using a portable locator in a particular orientation; and e) using the measured additional local flux intensity in establishing a predicted locate line angular orientation which, at least to an approximation, limits the possible directions to and orientations of a predicted locate line relative to the particular orientation of the portable locator at the side locating above ground point.