LiDAR Hits the Rails

Posted: 8/28/2013

LiDAR Hits the Rails Print E-mail
Written by Larry Trojak
Friday, 23 August 2013


Much like the apps that proliferate on our smart phones today, LiDAR is one of those technologies for which the possibilities seem, quite literally, endless. Already proven in a host of survey and construction-based operations, LiDAR has also proven its value in peripheral applications such as mining/aggregate inventory, forensic work, utility line inspection, GIS data gathering, and more. To that list, thanks to an ongoing project for the Wisconsin & Southern Railroad (WSOR), you can now add rail line clearance inspection. As part of a bridge maintenance program TerraTec Engineering, LLC (TerraTec) recently wrapped up the scanning of more than 570 miles of WSOR track using an IP-S2 LiDAR-based scanning system from Topcon Positioning Systems. When the full project is complete, TerraTec will present the railroad with a comprehensive database of potential clearance conflicts, as well as a point cloud scan of the full route (along with corresponding photo documentation) allowing the railroad to improve its shipping and maintenance efforts.

Progressive Rail Industry
For many, railroads conjure up mental images of a stodgy, passť form of transportation utilizing outdated technology. In actuality, however, the rail industry is quite progressive, using everything from ultrasonic sensors to detect cracks in wheels, to onboard GPS for fleet navigation and tracking. So, according to Jeff Francis, co-owner and principal with Cedarburg, WI-based TerraTec, it should not be surprising that, when soliciting bids for companies to play a key role in their bridge maintenance program, WSOR insisted that the effort include LiDAR-based technology.

"The railroad had a very definite plan in mind when they set out to do this," he said. "They wanted proposals for a bridge management project and we won the bid as a sub-consultant to Graef USA, the prime on the job. The overall project is to rate, evaluate and create a management plan for their bridge system, but a major component of it specified that the company chosen had to scan the bridges and the corridor for clearance purposes."

TerraTec responded to those needs with Topcon's IP-S2 LiDAR-based mobile scanning system which they leased from the Waukesha, WI branch of Positioning Solutions Company (PSC). Other choices available to them included the IP-S2 HD which offers a high-density, long-range LiDAR sensor for maximum visual mapping detail, as well as a host of advanced positioning and mapping features.

"We were confident that the IP-S2's range of features, including the Ladybug camera technology it offers as standard, were an ideal match for the project at hand," said Francis.

Scanning Rationale
While LiDAR scanning is not something the WSOR normally does, Francis said they requested it to help them better understand the clearance envelope within their network.

"The long-term goal for the railroad was simple: if a shipper calls them with a load size, they want to be able to input that information into a database and immediately be able to determine where conflicts on the system might occur. They felt that scanning was the best way to start making that happen. We took it a step further and proposed creation of a database into which they would be able to input a load parameter to determine where--based