Noise Measurement In A Locating Receiver

• US 20150369953A1
• Filed: 06/22/2015
• Published: 12/24/2015
• Est. Priority Date: 06/23/2014
• Status: Active Grant

• Current Assignee: Charles Machine Works Inc (Toro)
• Original Assignee: Charles Machine Works Inc (Toro)
• Inventors: Bailey, Brian K., Gard, Michael F.
• Granted Patent: US 10,107,931 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01V 3/088 operating with electric fields G01V3/082 takes precedence
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: G01V 3/38 Processing data, e.g. for analysis, for interpretation, for correction

Abstract

A method for choosing a frequency to locate an underground object. A locating receiver is provided with a display. The locating receiver scans multiple pre-selected frequencies to determine a noise level, or a signal-to-noise ratio. The locating receiver transmits the chosen frequency to a transmitter, which places the chosen frequency on the underground object to provide an optimal locating frequency.

Claims

1. A locating system for locating an underground object comprising:

a locating receiver programmed to switch between a locate mode and a noise mode, wherein the locating receiver is configured to take a noise measurement at a plurality of locating frequencies when in noise mode; and

a processor configured to output a plurality of frequency data entries corresponding to the noise measurement;

wherein the locating receiver detects an electromagnetic field strength at a chosen frequency selected from the frequency data entries when in locate mode.

2. The locating system of claim 1 further comprising a display to display the plurality of locating frequencies.

3. The locating system of claim 2 wherein the chosen frequency is selected using the display.

4. The locating system of claim 1 wherein the processor logarithmically scales the noise measurement.

5. The locating system of claim 1 wherein the processor automatically selects the chosen frequency from the frequency data entries.

6. The locating system of claim 1 wherein the chosen frequency has a noise measurement higher in value than any other frequency data entries.

7. The locating system of claim 1 further comprising a transmitter operatively connected to the underground object.

8. The locating system of claim 7 further comprising a communication link between the locating receiver and the transmitter.

9. The locating system of claim 8 wherein the communication link comprises a wireless signal.

10. The locating system of claim 7 wherein the transmitter applies a signal current by electrical current induction to the underground object.

11. The locating system of claim 7 wherein the transmitter applies signal currents to the underground object at the plurality of locating frequencies such that the processor generates a signal-to-noise ratio at each of the plurality of locating frequencies when the locating receiver is in noise mode.

12. The locating system of claim 11 wherein the signal currents applied by the transmitter have variable magnitudes.

13. A method of detecting an underground object comprising:

taking a plurality of noise measurements with a locating receiver at a plurality of locate frequencies to generate a plurality of frequency data entries;

selecting a chosen frequency corresponding to one of the plurality of frequency data entries; and

detecting the underground object at the chosen frequency with the locating receiver.

14. The method of claim 13 wherein the chosen frequency has a maximum noise level relative to the plurality of locate frequencies.

15. The method of claim 14 further comprising selecting the chosen frequency with the locating receiver and locating the underground object using the locating receiver without transmitting a signal current on the underground object at the chosen frequency.

16. The method of claim 13 further comprising transmitting a signal current on the underground object at the chosen frequency.

17. The method of claim 13 wherein the signal current is generated on the underground object through direct electrical connection between the underground object and a transmitter.

18. The method of claim 13 further comprising transmitting a signal current on the underground object at the plurality of locate frequencies.

19. The method of claim 18 further comprising:

taking a signal measurement at the plurality of locate frequencies when the signal current is transmitted; and

generating a signal-to-noise ratio at the plurality of locate frequencies.

20. The method of claim 19 wherein the signal current generated at the plurality of locate frequencies has a variable magnitude.

21. The method of claim 19 further comprising transmitting a signal current on the underground object at the chosen frequency.

22. The method of claim 13 further comprising transmitting a signal current on the underground object at the chosen frequency, wherein the chosen frequency of the signal current is automatically selected by a processor.

23. The method of claim 13 wherein the underground object comprises one of the group consisting of:

a beacon attached to a drill string, a buried utility wire, a buried conductive pipe and a buried non-conductive pipe comprising a tracer wire.

24. The method of claim 13 wherein the frequency data entries are simultaneously displayed at the locating receiver.

25. The method of claim 13 further comprising displaying frequency data entries corresponding to the plurality of noise measurements taken by the locating receiver at the plurality of locate frequencies.

26. A method for locating a buried utility comprising:

taking a plurality of noise measurements at a plurality of locate frequencies at an above ground location;

displaying a plurality of frequency data entries corresponding to the plurality of noise measurements;

choosing a chosen locate frequency corresponding to one of the plurality of frequency data entries;

transmitting a signal on the buried utility at the chosen locate frequency;

detecting the signal at the above-ground location; and

determining a location of the buried utility relative to the above-ground location.

27. The method of claim 26 further comprising:

transmitting a signal current on the underground object at the plurality of locate frequencies;

taking a signal measurement at the plurality of locate frequencies when the signal current is transmitted; and

generating a signal-to-noise ratio at the plurality of locate frequencies.