Gas detection systems and methods using measurement position uncertainty representations

Patent metadata

Field	Value
Publication number	US-10598562-B2
Application number	US-201514948287-A
Country	US
Kind code	B2
Filing date	Nov 21, 2015
Priority date	Nov 21, 2014
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

In some embodiments, a natural gas leak detection system generates display content including indicators of remote and local potential leak source areas situated on a map of an area of a gas concentration measurement survey performed by a vehicle-borne device. The remote area may be shaped as a wedge extending upwind from an associated gas concentration measurement point. The local area graphically represents a potential local leak source area situated around the gas concentration measurement point, and having a boundary within a predetermined distance (e.g. 10 meters) of the gas concentration measurement point. The local area may be represented as a circle, ellipse, or other shape, and may include an area downwind from the measurement point. Size and/or shape parameters of the local area indicator may be determined according to survey vehicle speed and direction data, and/or wind speed and direction data characterizing the measurement point.

First claim

What is claimed is:

1. A natural gas leak detection system comprising:
at least one hardware processor and associated memory configured to generate display content according to gas concentration and associated wind direction and wind magnitude data characterizing a gas concentration measurement run performed by a mobile gas measurement device; and
a display device coupled to the at least one hardware processor and associated memory, the display device configured to present the display content;
wherein generating the display content comprises
identifying at least one angular search area suspected to have a natural gas leak source, the search area having an axis indicating a representative wind direction relative to a geo-referenced location of a gas concentration measurement point, and the search area having a width relative to the axis, wherein the width is indicative of a wind direction variability characterizing a plurality of wind direction measurements in an area of the gas concentration measurement point;
identifying a local potential leak source area, the local potential leak source area representing a potential local leak source area centered at the gas concentration measurement point and extending within no more than 10 meters of the gas concentration measurement point; and
graphically highlighting a part of a display of a street map selectively within the identified angular search area and local potential leak source area.

2. The system of claim 1 , wherein the potential local leak source area comprises an area downwind from the gas concentration measurement point.

3. The system of claim 1 , wherein the local potential leak source area is identified according to a survey vehicle speed characterizing the gas concentration measurement point.

4. The system of claim 3 , wherein the local potential leak source area is identified according to a wind speed characterizing the gas concentration measurement point.

5. The system of claim 4 , wherein the local potential leak source area is identified according to a survey vehicle direction characterizing the gas concentration measurement point.

6. The system of claim 5 , wherein the local potential leak source is identified according to a wind direction characterizing the gas concentration measurement point.

7. The system of claim 1 , wherein the local potential leak source area is a closed area having a rounded boundary.

8. The system of claim 1 , wherein the local potential leak source area is shaped as a circle.

9. The system of claim 8 , wherein the circle has a radius representing a geographical distance between 10 and 30 feet.

10. The system of claim 9 , wherein the radius represents a geographical distance between 15 and 25 feet.

11. The system of claim 1 , wherein the local potential leak source area indicator has a shape elongated along a measurement path at the geo-referenced location of the gas concentration measurement point.

12. The system of claim 1 , wherein the local potential leak source area is shaped as an ellipse.

13. The system of claim 12 , wherein a major axis of the ellipse is tangential to a measurement path at the geo-referenced location of the gas concentration measurement point.

14. The system of claim 13 , wherein a length of the major axis of the ellipse is representative of an uncertainty in the determination of the geo-referenced location along a tangent to the measurement path at the geo-referenced location of the gas concentration measurement point.

15. The system of claim 13 , wherein a length of the major axis of the ellipse is determined such that an estimated frequency at which near- or under-vehicle leak locations fall inside a boundary of the ellipse satisfies a probability condition.

16. The system of claim 13 , wherein a length of the major axis of the ellipse is determined according to a survey vehicle speed characterizing the gas concentration measurement point.

17. The system of claim 13 , wherein a length of the minor axis of the ellipse is determined according to a wind speed characterizing the gas concentration measurement point.

18. The system of claim 13 , wherein a length of the minor axis of the ellipse is determined according to data representative of local atmospheric stability at the gas concentration measurement point.

19. The system of claim 13 , wherein a length of a minor axis of the ellipse is determined according to an uncertainty in the determination of the geo-referenced location along a direction perpendicular to the measurement path at the geo-referenced location of the gas concentration measurement point.

20. The system of claim 13 , wherein a length of a minor axis of the ellipse is determined according to a characteristic distance from which upwind leaks near the measurement path are detectable.

21. The system of claim 13 , wherein a length of the minor axis of the ellipse is determined such that an estimated frequency at which near- or under-vehicle leak locations fall inside a boundary of the ellipse satisfies a probability condition.

22. The system of claim 1 , wherein the width of the search area indicator is determined according to a survey vehicle speed and a wind speed characterizing the gas concentration measurement point.

23. The system of claim 22 , wherein the width of the search area indicator is determined according to a function that increases with the survey vehicle speed characterizing the least one gas concentration measurement point, and decreases with the wind speed characterizing the gas concentration measurement point.

24. The system of claim 1 , wherein the width of the search area indicator is determined according to an angular standard deviation characterizing the plurality of wind direction measurements.

25. The system of claim 1 , wherein the display content further comprises:
at least one path on the map indicating a route of travel by the mobile gas measurement device, and
at least one indicator on the map that indicates a surveyed area for at least one potential gas leak source, wherein the surveyed area adjoins the path and extends in a substantially upwind direction from the path, wherein the surveyed area is determined according to:
a wind direction variability characterizing a plurality of wind direction measurements performed along the route of travel; and
a measurement uncertainty characterizing a plurality of wind directions relative to ground determined from the plurality of wind direction measurements.

26. A non-transitory computer-readable medium encoding instructions which, when executed by at least one hardware processor and associated memory, cause the at least one hardware processor and associated memory to generate display content for presentation on a display device, the display content being generated according to gas concentration and associated wind direction and wind magnitude data characterizing a gas concentration measurement run performed by a mobile gas concentration measurement device, wherein generating the display content comprises:
identifying at least one angular search area suspected to have a natural gas leak source, the search area having an axis indicating a representative wind direction relative to a geo-referenced location of a gas concentration measurement point, and the search area having a width relative to the axis, wherein the width is indicative of a wind direction variability characterizing a plurality of wind dir

Assignees

• Picarro Inc

Inventors

• Steele David
• Rella Chris W
• Tan Sze M
• Van Pelt Aaron

Classifications

• G01P5/02

  by measuring forces exerted by the fluid on solid bodies, e.g. anemometer · CPC title

• G01C21/3697

  Output of additional, non-guidance related information, e.g. low fuel level (G01C21/3679 takes precedence) · CPC title

• G01P13/02

  Indicating direction only, e.g. by weather vane · CPC title

• F17C2250/0647

  Concentration of a product · CPC title

• G01M3/04

  by detecting the presence of fluid at the leakage point · CPC title