A low flying helicopter circled the downtown core over Maple Ridge on Tuesday raising the eyebrows of most who saw it.
It was not filming for a movie, though, it was doing an aerial inspection, part of work being done across the Lower Mainland, explained Fred Armstrong with the City of Maple Ridge.
In fact, it was inspecting high pressured gas transmission lines for FortisBC.
“We’re flying a LiDAR system overlooking for methane leaks on their gas transmission pipelines,” explained Tim Goolsby, president of LaSen Inc., the company that developed the ALPIS system.
How the system works is an eye-safe laser beam is transmitted from the aircraft to illuminate the area on the ground above and around the buried pipe at 400 times per second. If the laser beam encounters gas emanating from a leak, the plume of gas will absorb a finite quantity of laser light and so the amount of laser that returns to the system is diminished.
The exact location of the methane leak is then precisely recorded using GPS coordinates and the leak location is also marked on a map with high definition pictures.
The LiDAR system is attached to the front of a Talon twin star duel engine helicopter, one of the only helicopters in Canada to have a low waiver permit that is needed for safety, explained Goolsby.
LaSen Inc. performs the survey for FortisBC every year across an area that stretches from Vancouver to Fort St. John.
Only one area is done per day.
The FortisBC survey began about two weeks ago and will be wrapping up in about a week or so, noted Goolsby.
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