	US 7,562,722 B2
	Method and apparatus for establishing the position of a sonde in a region using a single detector
Guenter W. Brune, Bellevue, Wash. (US); Peter H. Hambling, Bellevue, Wash. (US); John E. Mercer, Kent, Wash. (US); Lloyd A. Moore, Renton, Wash. (US); Shiu S. Ng, Kirkland, Wash. (US); and Rudolf Zeller, Seattle, Wash. (US)
Assigned to Merlin Technology, Inc., Reaton, Wash. (US)
Filed on Jan. 29, 2008, as Appl. No. 12/22,093.
Application 10/694926 is a division of application No. 10/353718, filed on Jan. 28, 2003, granted, now 6,668,944, filed on Dec. 30, 2003.
Application 12/022093 is a continuation of application No. 11/343375, filed on Jan. 30, 2006, granted, now 7,347,280.
Application 11/343375 is a continuation of application No. 10/694926, filed on Oct. 27, 2003, granted, now 7,021,403, filed on Mar. 04, 2006.
Application 10/353718 is a continuation of application No. 10/039971, filed on Oct. 25, 2001, granted, now 6,536,538, filed on Mar. 25, 2003.
Application 10/039971 is a continuation of application No. 09/845238, filed on Apr. 30, 2001, granted, now 6,364,035, filed on Apr. 02, 2002.
Application 09/845238 is a continuation of application No. 09/324221, filed on Jun. 01, 1999, granted, now 6,250,402, filed on Jun. 26, 2001.
Application 09/324221 is a continuation in part of application No. 08/835834, filed on Apr. 16, 1997, granted, now 6,035,951, filed on Mar. 14, 2000.
Prior Publication US 2008/0121431 A1, May 29, 2008
Int. Cl. E21B 47/02 (2006.01)

U.S. Cl. 175—62 [175/45; 324/326]

9 Claims

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.