When engineering firm J.L. Patterson & Associates (JLP) needed ground control for a mobile LiDAR rail survey in January 2014, they turned to Rancho Cucamonga, Calif.-based WestLAND Group, Inc. It was the perfect test project for WestLAND Group’s total station scanner, which the firm had purchased a month earlier.
Sophisticated users of 3D spatial data, JLP wanted WestLAND Group to set control along and within several railroad tunnels near the Mexican border, and someone else would be doing the LiDAR work.
JLP was used to working with point clouds but didn’t necessarily think of WestLAND when it came to having scanning capabilities. WestLAND proposed that they not only provide control, but, “while we were out there…” scan one tunnel with the Leica Nova MS50 MultiStation and see if the deliverable worked and was cost-effective. The offer was accepted, and the WestLAND team got started.
The work was ultimately for Pacific Imperial Railroad (PIR) on a section of rail known as “The Impossible Railroad.” PIR is rehabilitating the Impossible Railroad for use with double stacked trains, and 17 tunnels will have to be surveyed for clearance analysis and possible grading and track redesign. WestLAND Group viewed the scan of one tunnel as basically a marketing investment, offering to scan one of the smaller tunnels, No. 15, which was just 300 feet long. That was the team’s first project use of the MS50, and it went very well.
While traversing through the tunnel using the Nova MS50 for the control survey, the crew switched the instrument to scan mode and, since it was already on basis, started the scans immediately. Just a few setups were needed, and scanning the entire tunnel took just a couple of extra hours in the field. The scanning time fit into the crew’s day easily, giving them time to clean up their notes and sketches, and take pictures of the site to supplement the MS50’s images.
In the office, the team has found the Leica Infinity software easy to use and impressive. They’re able to import and view the raw survey and scan data easily, and they can do a network adjustment to tighten up the precision of their control traverse, along with the corresponding conventional survey points and point cloud data. They’re then able to export all of the data into multiple file formats to be imported directly into MicroStation, AutoCAD Civil 3D, and/or Revit, depending on the particular project and deliverable requirements.
For the railroad project, WestLAND Project Surveyor Travis Mensen used Infinity to process and adjust the point cloud data and exported it to Bentley MicroStation V8i to create longitudinal breaklines along the rails and tunnel, which had a trapezoidal cross-section. He then created a MicroStation 3D deliverable according to the project specifications. All the point cloud processing work took about a day. Angelo used the information gained from this pilot project to prepare a proposal for the remaining 16 tunnels. J.L. Patterson liked the proposal and said the work was effective for the clearance analysis and design work. WestLAND expects to get the project when JLP gets the go ahead from the client.
The pilot project has already paid off with additional work. JLP later asked WestLAND for an obstruction/clearance survey of an existing bridge, together with surrounding topography along existing tracks in a railroad yard, and scanning was specified for the project. It only took about an hour to review and incorporate the point cloud into the drawing.