Omnidirectional sonde and line locator

• US 20040070399A1
• Filed: 10/09/2002
• Published: 04/15/2004
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: Seek Tech, Inc.
• Original Assignee: Seek Tech, Inc.
• Inventors: Kolb, Thomas R., Barnicoat, Bradley D., Cox, David A., Merewether, Ray, Olsson, Mark S., Martin, Michael J., Hilton, Randall P.
• Granted Patent: US 7,009,399 B2
• Time in Patent Office: Days
• US Class Current: 324/326
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat

Abstract

At least one antenna array including three mutually orthogonal antennas each sharing a common center point senses an electromagnetic signal emitted by a buried object such as a utility line, pipe or sonde. A circuit at least partially mounted in a housing is connected to the array and determines a location of the buried object by measuring signal strength and field angles in three dimensions without having to align the antenna array relative to the buried object while eliminating nulls and false peaks. A graphical user interface (GUI) has user-friendly icons, symbols, menus, numbers and graphical and auditory representation of signal strength. A SEARCH view indicates signal strength by showing a rotating strength indicator, a trace mode MAP view in which line location is shown by a line that moves side-to-side, and a sonde mode MAP view in which sonde location is shown by a moving line, pole and equator.

Claims

1. An omnidirectional manually portable system for locating a buried object by sensing an electromagnetic signal emitted by the buried object, comprising:

at least one antenna array including three substantially mutually orthogonal antennas each sharing a common center point;

a housing connected to and supporting the antenna array; and

circuit means at least partially mounted in the housing and connected to the antennas in the antenna array for sensing an electromagnetic signal emitted from a buried object and determining a location of the buried object by measuring signal strength and field angles in three dimensions.

2. The system of claim 1 wherein the circuit means senses an electromagnetic signal in a frequency range of approximately 50 Hz to 500 kHz.

3. The system of claim 1 wherein each of the three antennas has a circular configuration.

4. The system of claim 1 wherein the array is mounted to an elongate member that is connected to the housing, the elongate member having a central axis that extends through the common center point.

5. The system of claim 4 wherein an angle subtended between the central axis and each of the antennas is substantially identical.

6. The system of claim 1 wherein a portion of the circuit means is mounted inside the antenna array.

7. The system of claim 1 wherein the circuit means includes a display mounted in the housing and means for driving the display to provide a visual indication of the determined location of the buried object.

8. The system of claim 1 wherein the circuit means includes an audio transducer and means for driving the audio transducer to provide an audible indication of the determined location of the buried object.

9. The system of claim 1 and further comprising a fourth antenna spaced from the antenna array and connected to the circuit means for determining a depth of the buried object based on the electromagnetic signal sensed by all of the antennas.

10. The system of claim 4 and further comprising a second antenna array mounted to the elongate member and spaced from the one antenna array, the second antenna array also including three substantially mutually orthogonal antennas, and the second antenna array being connected to the circuit means for determining a depth of the buried object based on the electromagnetic signal sensed by all of the antennas.

16. The method of claim 1 wherein the topside area is simultaneously traversed with a fourth antenna spaced from the antenna array and a depth of the buried object is determined based on the electromagnetic signal sensed by all of the antennas.

11. A method of locating a buried object by sensing an electromagnetic signal emitted by the object, comprising:

traversing a topside area beneath which an object emitting an electromagnetic signal is buried with at least one antenna array including three substantially mutually orthogonal antennas;

sensing the electromagnetic signal emitted from the buried object with the one array; and

determining a location of the buried object based on the sensed electromagnetic signal without having to align the antenna array relative to the buried object and while eliminating nulls and false peaks.

12. The method of claim 11 wherein the electromagnetic signal has a frequency in a range of approximately 50 Hz to 500 kHz.

13. The method of claim 11 wherein the three antennas are each coils that share a common center point.

14. The method of claim 11 and further comprising the step of providing a visual indication of the determined location of the buried object.

15. The method of claim 11 and further comprising the step of providing an audible indication of the determined location of the buried object.

17. The method of claim 11 wherein the buried object is a long conductor that emits an electromagnetic signal that produces an elongated cylindrical field.

18. The method of claim 11 wherein the topside area is simultaneously traversed with a second antenna array including at least a pair of antennas in order to avoid a null detection.

19. The method of claim 11 wherein the buried object is a sonde.

20. An omnidirectional manually portable system for locating a buried object by sensing an electromagnetic signal emitted by the object, comprising:

a first antenna array including three substantially mutually orthogonal antennas in the form of a first plurality of coils sharing a first common center point;

a second antenna array including three substantially mutually orthogonal antennas in the form of a second plurality of coils sharing a second common center point;

a housing including a handle portion;

an elongate member connecting the first and second antenna arrays to the housing and extending through the first and second common center points and supporting the first and second antenna arrays in spaced apart relation; and

circuit means at least partially mounted in the housing and connected to the antennas in the first and second antenna arrays for sensing an electromagnetic signal having a frequency in a range of approximately 50 Hz to 500 kHz emitted by a buried object and determining a location and depth of the buried object by measuring signal strength and field angles in three dimensions utilizing the first and second antenna arrays, the circuit means including means for providing a visual and/or audible indication of the determined location and depth of the buried object.

21. An omnidirectional manually portable system for locating buried lines by sensing an electromagnetic signal, comprising:

a manually portable housing including a display;

at least one antenna array mounted to the manually portable housing; and

circuit means at least partially mounted in the manually portable housing and connected to the array for sensing an electromagnetic signal emitted from a buried line and determining a location of the buried line by measuring signal strength and field angles, including means for causing the display to indicate a graphic line that moves on the display to represent a location of the antenna array relative to the buried line.

22. An omnidirectional manually portable system for locating buried objects by sensing an electromagnetic signal, comprising:

a housing including a display;

at least one antenna array mounted to the housing; and

circuit means at least partially mounted in the housing and connected to the array for sensing an electromagnetic signal emitted from a buried object and determining a location of the buried object by measuring signal strength and field angles, including means for causing the display to show a signal strength indicator that moves in a non-linear manner in a first direction in proportion to an increasing amount of electromagnetic signal sensed by the antenna array and in a second direction in proportion to a decreasing amount of electromagnetic signal sensed by the antenna array.

23. The system of claim 22 wherein the circuit means causes the display to rotate the signal strength indicator around a track pattern.

24. The system of claim 22 wherein the circuit means further includes means for generating an audible indication that represents both the direction and amount of sensed electromagnetic signal.

25. The system of claim 23 wherein the circuit means cause a numerical value of the electromagnetic signal sensed by the antenna array to be indicated in a central region of the track pattern.

26. The system of claim 22 wherein the circuit means also causes the display to indicate a graphic line that moves on the display to represent a location of the antenna array relative to the buried object.

27. An omnidirectional manually portable system for locating buried objects using an electromagnetic signal, comprising:

a housing including a display;

at least one antenna array mounted to the housing and including three mutually orthogonal antennas; and

circuit means at least partially mounted in the housing and connected to the array for sensing a substantially dipole electromagnetic field emitted by a buried sonde and determining a location of the buried sonde by measuring signal strength and field angles, including means for causing the display to indicate a sonde axis and at least one pole that moves on the display to represent a location of the antenna array relative to the buried sonde.

28. The system of claim 27 wherein the circuit means also causes the display to indicate an equator.

29. The system of claim 27 wherein the circuit means also causes the display to indicate a zoom ring when the antenna array is close to a pole, the zoom ring representing a magnified search area near the pole.

30. An omnidirectional manually portable system for locating buried lines using an electromagnetic signal, comprising:

a housing including a display;

at least one antenna array mounted to the housing; and

circuit means at least partially mounted in the housing and connected to the array for sensing a substantially cylindrically shaped electromagnetic field emitted by a buried line and determining a location of the buried line by measuring signal strength and field angles, including means for causing the display to indicate representation of a globe in which the measured field angle is shown as being located on the pole if it is at ninety degrees and shown as being on the equator if it is at zero degrees.

31. An omnidirectional manually portable system for locating buried objects by sensing an electromagnetic signal, comprising:

a housing including a display;

at least one antenna array mounted to the housing; and

circuit means at least partially mounted in the housing and connected to the array for sensing an electromagnetic signal emitted from a buried object and determining a location of the buried object by measuring signal strength and field angles, including means for causing the display to show a currently sensed signal strength, means for storing a maximum sensed signal strength, and means for providing a visual indication whenever the current signal strength shown on the display is equal to the maximum signal strength that has been sensed during a locating session.

32. A manually portable system for locating buried objects by sensing an electromagnetic signal, comprising:

a housing including a display;

at least one antenna array mounted to the housing;

circuit means at least partially mounted in the housing and connected to the array for sensing an electromagnetic signal emitted from a buried object and determining a location of the buried object by measuring signal strength and field angles, including means for causing the display to show a sensed signal strength;

a plurality of markers; and

means connected to the housing for removably mounting the markers.

33. The system of claim 32 wherein the antenna array is mounted on a mast connected to the housing and the markers are removably mounted on the mast.

34. The system of claim 32 wherein the mounting means includes a post with an enlarged outer end.

35. The system of claim 34 wherein the markers each have starred apertures with deflectable fingers that yield to allow that markers to snapped over the enlarged outer end of the post.