Aggregate leak indicator display systems and methods
In some embodiments, data from a vehicle-borne gas leak detection survey are used to generate an aggregate leak indication search area (LISA) indicator for a plurality of leak indications (measurement peaks) characterizing a single leak or localized set of leaks. A clustering algorithm (e.g. Markov, DBScan) may be used to group a set of indications into a cluster characterizing the leak. Leak indications may be pre-filtered for quality control before assignment to a cluster according to a number of parameters including background gas level, inter-peak distance, peak shape, wind speed, wind direction and/or variability, vehicle speed and/or acceleration, and/or a lower detection threshold for leak flow rate.
1. A system comprising:
a vehicle-borne gas concentration measurement device configured to conduct a gas leak detection survey by performing a sequence of geospatially-referenced mobile gas concentration measurements along one or more survey paths to collect data including gas concentration and location; and
at least one hardware processor coupled to the gas concentration measurement device and configured to:
group a plurality of gas leak indications into a cluster representing a corresponding leak, each gas leak indication corresponding to a detected gas concentration peak; and
generate an aggregate leak detection graphical indicator positioned on a map of a survey area, the aggregate graphical indicator representing the cluster, the graphical indicator having a width representing a variability of wind direction values across the plurality of gas leak indications.
2. The system of claim 1 , wherein grouping the plurality of gas leak indications comprises performing density-based spatial clustering using a maximum distance scale and a minimum number of points per cluster as input parameters to distinguish between members and non-members of the cluster.
3. The system of claim 1 , wherein grouping the plurality of gas leak indications comprises carrying out Markov clustering by performing a random walk through points representing gas leak indications to distinguish between members and non-members of the cluster.
4. The system of claim 1 , wherein grouping the plurality of gas leak indications comprises employing wind directions values corresponding to gas leak indications to distinguish between members and non-members of the cluster.
5. The system of claim 1 , wherein grouping the plurality of gas leak indications comprises sorting the plurality of indications by amplitude, identifying an indication with a locally-maximum amplitude, identifying gas leak indications within a predetermined distance of the indication with the locally-maximum amplitude, and grouping the gas leak indications within the predetermined distance into the cluster.
6. The system of claim 1 , wherein the at least one hardware processor is further configured to generate a textual indicator positioned on the map, the textual indicator displaying at least one quantity characterizing the cluster and corresponding leak, the at least one quantity being selected from a leak flow rate, a type of gas, a confidence in the type of gas, a source type attribution, and a confidence in the source type attribution.
7. The system of claim 1 , wherein the aggregate graphical indicator has a length along a representative wind direction characterizing the cluster, the length representing a maximum detection distance value at which a gas leak is detectable by the survey across the plurality of gas leak indications.
8. The system of claim 1 , wherein the aggregate graphical indicator includes a central spatial-localization region representing a location of the cluster on the map, and a directional indicator extending upwind from the central spatial-localization region, the directional indicator being characterized by the width.
9. The system of claim 1 , wherein the at least one hardware processor is configured to filter out a subset of gas leak indications to identify the plurality of gas leak indications in the cluster.
10. The system of claim 9 , wherein filtering out the subset of gas leak indications comprises applying at least one filter selected from a filter based on a background level of natural gas, and a filter based on an inter-peak distance for gas leak detections.
11. The system of claim 9 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a peak shape of each gas leak indication.
12. The system of claim 9 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a wind speed characterizing each gas leak indication.
13. The system of claim 9 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a wind direction characterizing each gas leak indication.
14. The system of claim 9 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a wind direction variability characterizing each gas leak indication.
15. The system of claim 9 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a vehicle speed and a vehicle acceleration characterizing each gas leak indication.
16. The system of claim 9 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a lower detection threshold for a leak flow rate characterizing each gas leak indication.
17. A method comprising:
employing a vehicle-borne gas concentration measurement device to conduct a gas leak detection survey by performing a sequence of geospatially-referenced mobile gas concentration measurements along one or more survey paths to collect data including gas concentration and location; and
employing at least one hardware processor coupled to the gas concentration measurement device to:
group a plurality of gas leak indications into a cluster representing a corresponding leak, each gas leak indication corresponding to a detected gas concentration peak; and
generate an aggregate leak detection graphical indicator positioned on a map of a survey area, the aggregate graphical indicator representing the cluster, the graphical indicator having a width representing a variability of wind direction values across the plurality of gas leak indications.
18. The method of claim 17 , wherein grouping the plurality of gas leak indications comprises performing density-based spatial clustering using a maximum distance scale and a minimum number of points per cluster as input parameters to distinguish between members and non-members of the cluster.
19. The method of claim 17 , wherein grouping the plurality of gas leak indications comprises carrying out Markov clustering by performing a random walk through points representing gas leak indications to distinguish between members and non-members of the cluster.
20. The method of claim 17 , wherein grouping the plurality of gas leak indications comprises employing wind directions values corresponding to gas leak indications to distinguish between members and non-members of the cluster.
21. The method of claim 17 , wherein grouping the plurality of gas leak indications comprises sorting the plurality of indications by amplitude, identifying an indication with a locally-maximum amplitude, identifying gas leak indications within a predetermined distance of the indication with the locally-maximum amplitude, and grouping the gas leak indications within the predetermined distance into the cluster.
22. The method of claim 17 , further comprising generating a textual indicator positioned on the map, the textual indicator displaying at least one quantity characterizing the cluster and corresponding leak, the at least one quantity being selected from a leak flow rate, a type of gas, a confidence in the type of gas, a source type attribution, and a confidence in the source type attribution.
23. The method of claim 17 , wherein the aggregate graphical indicator has a length along a representative wind direction characterizing the cluster, the length representing a maximum detection distance value at which a gas leak is detectable by the survey across the plurality of gas leak indications.
24. The method of claim 17 , wherein the aggregate graphical indicator includes a central spatial-localization region representing a location of the cluster on the map, and a directional indicator extending upwind from the central spatial-localization region, the directional indicator being characterized by the width.
25. The method of claim 17 , wherein the at least one hardware processor is configured to filter out a subset of gas leak indications to identify the plurality of gas leak indications in the cluster.
26. The method of claim 25 , wherein filtering out the subset of gas leak indications comprises applying at least one filter selected from a filter based on a background level of natural gas, and a filter based on an inter-peak distance for gas leak detections.
27. The method of claim 25 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a peak shape of each gas leak indication.
28. The method of claim 25 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a wind speed characterizing each gas leak indication.
29. The method of claim 25 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a wind direction characterizing each gas leak indication.
30. The method of claim 25 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a wind direction variability characterizing each gas leak indication.
31. The method of claim 25 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a vehicle speed and a vehicle acceleration characterizing each gas leak indication.
32. The method of claim 25 , wherein filtering out the subset of gas leak indications comprises applying a filter based on a lower detection threshold for a leak flow rate characterizing each gas leak indication.
33. A non-transitory computer-readable medium encoding instructions which, when executed by a computer system comprising a hardware processor and an associated memory, cause the computer system to:
receive survey data collected by a vehicle-borne gas concentration measurement device configured to conduct a gas leak detection survey by performing a sequence of geospatially-referenced mobile gas concentration measurements along one or more survey paths to collect data including gas concentration and location;
group a plurality of gas leak indications into a cluster representing a corresponding leak, each gas leak indication corresponding to a detected gas concentration peak; and
generate an aggregate leak detection graphical indicator positioned on a map of a survey area, the aggregate graphical indicator representing the cluster, the graphical indicator having a width representing a variability of wind direction values across the plurality of gas leak indications.