Patrick Crawford and Scott Confer stood on a sidewalk in the West Bottoms of Kansas City and waited as the laser from their LiDAR (Light Detection and Ranging) scanner whorled and churned, capturing millions of data points and high-resolution photos of a large, nine-story brick building.
Just as the building has evolved from a manufacturing plant for horse-drawn carriages to a series of antique stores, so has the survey technology advanced from tape measures and hand-drawn sketches to an advanced laser ranging instrument with a five megapixel camera. Crawford and Confer work for Shafer, Kline & Warren (SKW), an engineering and surveying firm that traces its roots back to Tuttle-Ayers-Woodward, the firm that had originally surveyed that same building in 1902.
“It’s fascinating to look at these original surveys completed by surveyors from our firm next to the data obtained using our LiDAR equipment,” says Crawford, geospatial team leader at SKW. “It really highlights the advances in our industry while providing insight into our foundation as a company.”
Originally developed by NASA in the 1970s for space borne sensor deployment, LiDAR scanning technology has advanced over the past 40 years to become a proven method for multiple survey applications. The terrestrial LiDAR scanners used by SKW captures up to a million points of data per second from up to 250 meters away and displays survey-grade data in a three dimensional point cloud.
Ten years ago, SKW became one of the first engineering firms in the Kansas City area to obtain LiDAR equipment and train staff on it. The firm sent Confer to Leica Geosystems manufacturing facility in San Ramon, California, to receive training from the inventor of the scanner technology.
“To say I learned a lot during that week would be an understatement,” says Senior Project Manager Confer, who has worked at SKW for nearly 30 years. “That’s one of the things I really enjoy about SKW is their willingness to reach out a little further to be on the cutting edge of technology.”
Leveraging LiDAR for Energy and Infrastructure
Crawford and Confer lead the LiDAR scanning efforts for SKW. Crawford primarily works on energy projects, such as oil and gas facilities, power plants, substations and engine rooms, while Confer’s experience centers on buildings and infrastructure projects.
“LiDAR scanning lends itself well to oil and gas or industrial facilities because we can go in quickly and gather vast amounts of data without shutting down or interrupting any kind of process,” says Crawford. “We can document extremely complex and technical structures, take it back to the office, and use that data to create as-built drawings to do our design work.”
One of the examples of this type of application Crawford recalls is scanning a process engine compartment to find the exact center of a piston that needed to be replaced. With LiDAR scanning, Crawford was able to locate and project the center of the piston to the roof and provide the client with the exact location for contractors to drill a hole, allowing for the piston to be extracted and replaced without shutting down the plant.
For Confer, the scan subject is more often a historic building, streetscape or bridge. In Excelsior Springs, Missouri, Confer scanned a historic bridge that needed to be rebuilt. The city wanted the bridge replacement to preserve the historic appearance of the old bridge, so Confer used LiDAR to scan and generate plans for the bridge.
“We can extract a lot of information and generate plans from the data we gather with LiDAR,” says Confer. “We can see and measure every contour on the structure or the surface of the ground. We’re able to pick up pavement markings and manholes without ever stepping foot on the pavement.”
Confer and Crawford both say that they are still finding more applications for LiDAR scanning for an array of clients, assuring that the variety they both enjoy as part of their jobs will remain.
It All Ties Back to Surveying
In the corner of Scott Confer’s office rests an SKW sign dating back to the 1980s. The target icon that remains part of SKW’s logo was inspired by the sighting targets that were used on plumb bob strings, level rods and sighting tripods. It serves as a reminder of the firms roots that date back to 1885 when every surveyor carried one.
When scanning strategic locations around the subject or subject environment, Crawford and Confer use their survey skills to set temporary targets that serve as common points when viewing the subject from each vantage point. These targets connect and orient the scan data, creating the 3D point cloud. Several of these scan targets are measured using survey-grade GPS equipment.
“I think we are successful with LiDAR because we are able to mate the terrestrial scanner data with actual survey data,” says Confer. “Anybody can go out and buy a scanner, but as surveyors, we tie it down and geo-reference it with survey data, so the information we gather can be used as design drawings.”
While the vast amount of data captured with LiDAR sets it apart from previous survey methods and makes it applicable to multiple projects, it also takes a skilled eye and trained hand to apply that data to engineering problems.
“I have been scanning for four years now. I can think in LiDAR. Sure, you get a lot of data with LiDAR, but it takes someone with my knowledge and skillset to capture and make sense of that data,” says Crawford.
In a couple hours, the scan of the West Bottoms antique stores is complete. Having never stepped foot on a ladder or scaffolding, Confer and Crawford gather their scanner and targets and load up the SKW truck with more information than their colleagues from 1902 could have imagined. Within hours, they will be able to move through the 3D point cloud and render design elements, using new technology to build upon historic roots.