Utility locating systems, devices, and methods using radio broadcast signals

Patent metadata

Field	Value
Publication number	US-10670766-B2
Application number	US-201615360979-A
Country	US
Kind code	B2
Filing date	Nov 23, 2016
Priority date	Nov 25, 2015
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

Systems, devices, and methods for locating buried conductors using ambient electromagnetic signals, such as AM or other broadcast signals, are described. A buried utility locator may include a plurality of spatially separated antenna arrays, a receiver circuit coupled thereto, and a processing element programmed to process measurements of ambient electromagnetic signals and associated electromagnetic signals radiated from current induced in the buried conductor from the ambient signals to determine information about the buried conductor.

First claim

We claim:

1. A buried utility locator for detecting a buried conductor, comprising:
a locator housing;
a front end subsystem, coupled to or disposed in the locator housing, comprising a dodecahedral antenna array having 12 antenna coils for receiving electromagnetic signals and a receiver circuit having corresponding inputs coupled to the twelve antenna coil outputs of the dodecahedral antenna array, the receiver circuit including electronics to receive an output signal from the dodecahedral antenna array antenna coil outputs at a broadcast radio frequency, the output signal from the dodecahedral antenna array coils including a first signal component from a signal sent directly from a broadcast transmitter and a second signal component emitted from the buried conductor as a result of current flow induced therein from the directly sent transmitter signal;
a processing element, operatively coupled to a receiver circuit output, programmed to process the receiver circuit output signal to separate the first signal component and second signal component and determine, based in part on the second signal component, information pertaining to the buried conductor; and
a non-transitory memory coupled to the processing element to store the determined information pertaining to the buried conductor.

2. The buried utility locator of claim 1 , further comprising receiving one or more additional electromagnetic signals at the front end subsystem, the one or more additional electromagnetic signals comprising a combination of additional direct magnetic field signals emitted from another transmitting antenna and magnetic field signals emitted from the buried conductor resulting from electromagnetic coupling of the additional direct magnetic field signals emitted from the another transmitting antenna to the buried conductor;
wherein the determined information pertaining to the buried conductor is further based on processing the one or more additional electromagnetic signals to separate corresponding first and second signal components.

3. The buried utility locator of claim 2 , wherein the one or more additional electromagnetic signals include direct magnetic field signals emitted from a plurality of radio transmitting antennas located at different geographic locations relative to the buried utility locator.

4. The buried utility locator of claim 3 , wherein the direct magnetic field signals are emitted at different frequencies from the broadcast transmitter.

5. The buried utility locator of claim 3 , wherein the plurality of radio transmitting antennas are AM radio broadcast transmitters located about 30 degrees to 120 degrees apart from one another relative to the position of the buried utility locator.

6. The buried utility locator of claim 1 , wherein the radio transmitting antenna is a commercial AM radio broadcast antenna.

7. The buried utility locator of claim 1 further including a second antenna array, wherein the second antenna array located is spatially separated from the first antenna array along a vertical axis of the buried utility locator and wherein the determined information is further based on an output of the second antenna array.

8. The buried utility locator of claim 1 , wherein the determined information pertaining to the buried conductor includes a position and an orientation of the buried conductor relative to the buried utility locator.

9. The buried utility locator of claim 1 , wherein the determined information pertaining to the buried conductor includes a depth of the buried conductor below the buried utility locator or below a ground surface.

10. The buried utility locator of claim 1 , further comprising a visual display element, wherein the determined information pertaining to the buried conductor is rendered on the visual display element.

11. The buried utility locator of claim 1 , further comprising a positioning system receiver coupled to or disposed in the locator housing to determine an absolute location of the buried utility locator, wherein the determined absolute location of the buried utility locator is stored in the non-transitory memory in association with the determined information pertaining to the buried conductor.

12. The buried utility locator of claim 11 , wherein the positioning system receiver is a GPS receiver.

13. The buried utility locator of claim 11 , wherein the absolute location of the buried utility locator is in the form of latitude and longitude coordinates.

14. A method for determining information associated with a buried conductor using a buried utility locator, comprising:
receiving, simultaneously at a dodecahedral antenna array comprising 12 antenna coils and a another antenna array, spatially separated from the first antenna array, within a buried utility locator, an electromagnetic signal comprising a first signal component received directly from a transmitter which broadcasts a signal at a radio frequency and a second signal component emitted from the buried conductor as a result of a current signal therein induced from a signal directly from the transmitter, and providing outputs from the first antenna array and the second antenna array;
processing, at a receiver and processing element within the buried utility locator operatively coupled to the first antenna array and second antenna array outputs, the antenna array outputs to separate the first signal component and the second signal component;
determining, based at least in part on the separate second signal component, information pertaining to the buried conductor; and
storing the determined information associated with the buried conductor in a non-transitory memory associated with the buried utility locator.

15. The method of claim 14 , further comprising receiving one or more additional ambient electromagnetic signals comprising a combination of additional direct magnetic field signals emitted from a radio transmitting antenna, and magnetic field signals emitted from the buried conductor resulting from electromagnetic coupling of the direct magnetic field signal to the buried conductor; wherein the determined information pertaining to the buried conductor is further based on processing the one or more additional ambient electromagnetic signals.

16. The method of claim 14 , further comprising:
evaluating gradients based at least on comparing the first measurement with the second measurement; and
comparing the evaluated gradients with a predetermined threshold to gather the information pertaining to the buried conductor.

17. The method of claim 16 , wherein the gradients comprises one or more of vertical field gradients, shearing gradients, phase gradients, and magnetic field vector magnitude gradients.

18. The method of claim 14 , wherein processing the first measurement and the second measurement comprises evaluating magnitudes of magnetic field vectors at the corresponding first magnetic field antenna array and the second magnetic field antenna array.

19. The method of claim 14 , wherein processing the first measurement and the second measurement comprises evaluating azimuthal angles at the corresponding first antenna array and the second antenna array.

20. The method of claim 14 , wherein the information associated with the buried conductor includes a position and an orientation of the buried conductor relative to the buried utility locator.

21. The method of claim 14 , wherein the information associated with the buried conductor includes a depth of the buried conductor below the buried utility loc

Assignees

• Olsson Mark S
• Merewether Ray
• Bench Stephanie M
• Aldridge Sequoyah
• Wisecaver Paul
• Rutledge Austin
• Seescan Inc

Inventors

• Olsson Mark S
• Merewether Ray
• Bench Stephanie M
• Aldridge Sequoyah
• Wisecaver Paul
• Rutledge Austin

Classifications

• G01V3/15

  specially adapted for use during transport, e.g. by a person, vehicle or boat · CPC title

• G01V3/104 Primary

  using several coupled or uncoupled coils (G01V3/101 takes precedence) · CPC title

• G01V3/12 Primary

  operating with electromagnetic waves {(operating with millimetre waves G01V8/005)} · CPC title