How Technology Will Change the Way Infrastructure is Delivered
with Pape-Dawson Engineers
Posted on 09/30/2024 by Pape-Dawson Engineers
For over a decade, Austin was ranked the fastest-growing large metroplex in the United States. Although no longer in the number 1 spot, Austin continues to grow at a rapid rate. And that growth is not predicted to stop any time soon.
With numerous high-tech companies now calling Central Texas home, Austin has earned the nickname “Silicon Hills,” a nod to California’s Silicon Valley. Technology is advancing each day across all industries, and the A/E/C industry is no exception. The future of Greater Austin is being built (quite literally) through the utilization of new technologies that are paving the way for more efficient development of infrastructure.
Pape-Dawson’s Tom Ruschkewicz, RPLS, PLS, Senior Vice President of Survey/Geomatics, and Angela Livingston, CP, CMS-Lidar, GISP, Vice President of Geospatial Services, elaborate on how advancements in technology are changing how survey data is collected and analyzed.
Decades ago, surveyors in the field painstakingly recorded angles, elevations, and other data, then brought it back to the office for engineers to work from. Nowadays, laser scanning technology, known as LiDAR, has supercharged the surveying world, speeding up timelines and recording survey-grade meta-data information. But LiDAR technology continues to rely on survey personnel who walk the terrain. “Every project still uses surveying methodology,” says Tom. “We need them to geo-reference the sensor-collected data to real-world coordinate values.”
“Surveyors paint the roadside black-and-white chevrons, crosses, or checkerboards that enable us to accurately use LiDAR,” adds Angela. Surveyors might also need to take readings where scanners can’t go or identify aspects scanners cannot. “An operator might need to open a manhole cover and get information about what’s underneath and determine engineering conflicts that may need resolution,” explains Tom.
In these cases, surveyors augment their approach to data collection using advanced geospatial technology, such as:
Aerial LiDAR. Scanners flown on airplanes or helicopters are perfect for quickly capturing long, linear routes. “We can capture 20 miles in a few hours using aerial LiDAR, rather than days or weeks with a traditional survey crew,” says Tom. The higher the scanner is off the ground, the less detailed the picture it captures, but aerial LiDAR’s can capture 50 or more survey grade data points per meter (PPM), providing a high level of detail and accuracy that engineers need.
Mobile LiDAR. Truck-mounted scanners are slower than aerial platforms, but they get better definition traveling just above the surface. “You get more data points the lower to the ground you go,” says Angela, “and mobile LiDAR can get about 5,000 PPM.” It can also pick up details aerial LiDAR misses, such as surface utilities, signage, etc. Another benefit: sensors take data from all around the vehicle, including above it, which aerial scanners cannot do. Though it may only map 60 miles in a day (depending on road width, traffic, and other factors), it can scan through tunnels or under bridges and overpasses.
Terrestrial LiDAR. Survey crews can operate tripod-mounted scanners to fill in other methods’ gaps. “LiDAR is a line-of-sight technology,” Tom reminds, “so whatever the scanner on the mobile or aerial platform misses a static sensor on the ground needs to pick up.” Not simply a supplemental data source, the terrestrial scanner is the go-to solution for some areas. Setting it up in the four corners of an intersection can map the surroundings while keeping people and equipment safely out of traffic, for example. It also fits the bill when FAA restrictions prohibit aerial platforms or drones.
Drone-mounted LiDAR. Drones help where safety concerns or environmental considerations prohibit humans or vehicles from scanning. A new addition to Pape-Dawson’s collection specializes in navigating tight spaces, providing a new capability for data collection.
Body-mounted LiDAR. For congested areas, Pape-Dawson’s body-mounted NavVis scanner can take readings quickly and easily. Faster than terrestrial LiDAR collection, it comes in handy in walkable spaces inside buildings, under overpasses or bridges, sidewalks, and traffic intersections.
“We have a collection of impressive tools at our disposal to address all types of challenges,” Tom says, and each tool in Pape-Dawson’s kit has its own unique capability. “We won’t jeopardize the safety of our survey crews in unsafe site conditions,” and scanners win out on fidelity and speed: “A scanner can get 5,000 data points per meter, where a survey crew is lucky to get one point per meter…and the scanner can do it in a fraction of the time.” Still, the unique knowledge of survey personnel remains essential to the process. Angela sums up the approach: “Every project is different, and we look for the best way to use the tools together and create a custom solution.”
The geospatial team combines the collected data, constructing a point cloud that approximates the site’s terrain and structures. From that, they can produce deliverables to be used by the engineers for their design work. Engineers receive 2D and 3D drawings, as well as a triangulated surface that shows the terrain, viewable in geographic information system (GIS) or computer-aided design (CAD) software (including Civil 3D and Revit). From that essential starting point, the engineering work can commence, knowing the design rests on a firm foundation: a detailed understanding of the site.