Dipole locator using multiple measurement points

• US 7,786,731 B2
• Filed: 05/10/2006
• Issued: 08/31/2010
• Est. Priority Date: 05/13/2005
• Status: Active Grant

• Current Assignee: Charles Machine Works Incorporated The
• Original Assignee: Charles Machine Works Incorporated The
• Inventors: Brown, David R., Marshall, Bradley S., Cole, Scott B., Gard, Michael F.
• Primary Examiner(s): Aurora; Reena
• Application Number:
  US11/382,644
• Publication Number:
  US 20060254820A1
• Time in Patent Office: 1,574 Days
• Field of Search: 324/326, 324/343, 343787-788
• US Class Current: 324/326
• CPC Class Codes: E21B 47/0232 at least one of the energy sources or one of the detectors being located on or above the ground surface
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00
• CPC Class Codes: G01V 3/165 operating with magnetic or electric fields produced or modified by the object or by the detecting device with electromagnetic waves G01V3/17
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

A receiver and tracking system for identifying a location of a magnetic field source. In a preferred embodiment a plurality of tri-axial antennas are positioned at three distinct points on a receiver frame. Each antenna detects a magnetic field from a source and a processor is used to determine a location of the source relative to the frame using the antenna signals. Each tri-axial antenna comprises three windings in each of three channels defined by a support structure. The windings each define an aperture area. The windings have substantially identical aperture areas and have a common center point. The receiver may to display to the operator the relative location of the field source or may direct the operator to a spot directly above the field source.

Claims

1. A triaxial antenna comprising:

a support member comprising a first channel, a second channel, and a third channel;

a first winding supported in the first channel and defining an aperture area;

a second winding supported in the second channel and defining an aperture area;

a third winding supported in the third channel and defining an aperture area;

wherein the aperture area of each winding is the same; and

wherein the windings have a common center point.

2. The antenna of claim 1 wherein each of the three channels are orthogonal to each other and wherein each of the three channels comprises a substantially rectangular aperture.

3. The antenna of claim 2 wherein the second channel circumvents the first channel such that a long side of the rectangular cross-section of the second channel is adjacent to and perpendicular to a short side of the rectangular cross-section of the first channel;

and

wherein the third channel circumvents the second channel and the first channel such that a diagonal of the rectangular cross-section of the third channel is substantially coincident with a plane formed by the rectangular cross-section of the second channel.

4. The antenna of claim 3 wherein the diagonal of the third channel intersects the plane of the second channel at an angle of approximately 4 degrees.

5. The antenna of claim 1 wherein the support member comprises a lightweight plastic material.

6. The antenna of claim 5 wherein the support member comprises a first part and a second part;

and

wherein the first part is secured to the second part.

7. The antenna of claim 1 wherein each of the windings comprises magnet wire.

8. The antenna of claim 1 wherein the windings do not intersect each other.

9. A triaxial antenna comprising:

a support structure;

a first antenna coil supported by the support structure and defining an aperture area;

a second antenna coil supported by the support structure and defining an aperture area;

a third antenna coil supported by the support structure and defining an aperture area;

wherein the aperture areas of the antenna coils are equal; and

wherein the coils have a common center point.

10. The antenna of claim 9 wherein the support structure defines a first channel, a second channel, and a third channel;

and

wherein the first antenna coil is supported in the first channel; and

wherein the second antenna coil is supported in the second channel; and

wherein the third antenna coil is supported in the third channel.

11. The antenna of claim 10 wherein each of the three channels is orthogonal to the others.

12. The antenna of claim 9 wherein the aperture area of each of the antenna coils is defined by a substantially rectangular shape, the rectangular shape having rounded corners.

13. The antenna of claim 12 wherein the second coil circumvents the first coil such that a long side of the rectangular shape of the second coil is adjacent to and perpendicular to a short side of the rectangular shape of the first coil.

14. The antenna of claim 13 wherein the third coil circumvents the second coil and the first coil such that a diagonal of the rectangular shape of the third coil is substantially coincident with a plane formed by the rectangular shape of the second coil.

15. The antenna of claim 14 wherein the diagonal of the third coil intersects the plane of the second coil at an angle of approximately 4 degrees.