Patent ID: 7562722
Filing Date: 2009-07-21
Classification: B82Y,E21B,G01R,G01V,H01Q

Abstract:
1. A method for tracking the position and certain orientation parameters of a sonde in the ground as the sonde moves along a path which lies within a particular coordinate system, said method comprising: (a) configuring the sonde for transmitting an electromagnetic field; (b) providing only one detector, the detector having an electromagnetic field receiving antenna assembly including at least one antenna, positioning the detector provided at a fixed position and at a particular orientation within said coordinate system, and determining the position and particular orientation within said coordinate system of the antenna associated with the detector provided; (c) at least periodically transmitting said electromagnetic field from said sonde when the sonde is at certain positions on said path; (d) when the sonde is at one point on said path, establishing the position and said certain orientation parameters of the sonde within the coordinate system; (e) moving said sonde along said path which includes said one point and at least a subsequent second point; (f) when the sonde moves a distance along said path from said one point to said second point, measuring at least one component of the intensity of said electromagnetic field using said detector; and (g) determining, at least to an approximation, the position and said certain orientation parameters of the sonde at said second point within the coordinate system using the position of said sonde at said one point and said certain orientation parameters of the sonde at said one point along with said electromagnetic field intensity measurement or measurements at said second point.