Almost every day I receive a blog post from our Editor, Gene Roe, showcasing a new LiDAR application. This expansive technology is rapidly spider-netting its way into dozens of new frontiers. One of the most down-to-earth functional uses of LiDAR is related to site work, road building, and infrastructure construction.
In the spring of 2010 Topcon, Autodesk, and SPAR partnered to present a three-part webcast series focused on the use of LiDAR for transportation planning, design, and construction. My segment of the third webcast (Improving Road and Highway Design Workflows) demonstrated how Topcon’s IP-S2 Mobile Mapping System can be used for construction management. The webcast can be viewed by following this link: http://usa.autodesk.com/adsk/servlet/oc/offer?siteID=123112&id=14672227.
A complete 3D view of a highway project under construction can be obtained by a quick drive through – from the safety of a vehicle. Imagery from the system’s 360 spherical camera provides a complete visual record of the site conditions. From the office, an engineer can assess percent completion and compliance with contract requirements such as traffic control. Spatial Factory software enables the user to view images registered to the LiDAR point cloud. This unique software can be used to create digital punch lists and as-builts as construction progresses.
The totally digital site work project – planning, design, construction, as-builts, and owner maintenance – is now an easily achievable reality. LiDAR-based mobile mapping systems enable the fast acquisition of digital information to a level of detail that was formerly unachievable with conventional ground survey methods.
Last year, Richard Hill and Jeff Peterson of the PPI Group demonstrated how mobile LiDAR can be utilized for a road construction project. The PPI Group is located in the Pacific Northwest with offices in Portland, Oregon and Seattle, Washington. The demonstration was part of "Design to Dozer" – a two-day program sponsored by the Oregon DOT on August 17 & 18. The main focus of the program was designing a digital model that could be brought directly into Topcon’s 3DMC machine control systems to build the site without setting a single grade stake. You can visit ODOT’s website for pictures and more information about the event: http://www.oregon.gov/ODOT/HWY/GEOMETRONICS/dozer.shtml
As a added feature of the event, Hill and Peterson showed how the IP-S2 could be used to quickly and accurately acquire topographic information to monitor and verify earthwork production. By driving the site before breaking ground and then driving it again after the road was cut to design grades, they were we able to get a clear picture of earthmoving progress. Hill offered his comments about this new methodology. "There are so many advantages to this method of data collection over conventional methods that it becomes obvious very quickly that mobile scanning and imaging with the IP-S2 mounted on an off road vehicle is the best tool for the job when it comes to job site awareness", he said.
Clear across the globe in Australia, Rapid Survey Solutions (RSS) is using mobile mapping for a widening spectrum of typical civil / survey projects. One notable project was creating an as-built of a 2.8 mile section of pipeline right-of-way over steep terrain. RSS compared conventional survey methodology to their new-found mobile mapping solution – two weeks for conventional methods vs. less than one and a half days for the IP-S2 system. Only four hours of that total time were spent in data collection and processing, the remainder was office work.
Another exemplary project that clearly demonstrated the benefits of mobile mapping was a full-feature survey of a proposed route for a 18" diameter water line. The location was the western suburbs of metropolitan Melbourne. Deliverables included DOT-coded CAD drawings and DTM’s.
RSS covered 8 km of suburban streets in one day. Their analysis concluded that mobile mapping resulted in a 30-40% cost reduction over traditional field survey costs, with a quicker turn-around and full photographic records of the route conditions.
RSS purchased their system from Position Partners, Australia’s major distributor for survey, GNSS, machine control, and mobile mapping products. A complete case study on RSS can be viewed and downloaded at: http://www.topconpositioning.com/fileadmin/uploads/pics/IS-P2/RSS_Case_Study.pdf.
LiDAR/camera-based mobile mapping systems are really the perfect solution for all phases of site work construction and management. This solution also extends to owner management after the project is completed. As facilities age with time, maintenance becomes an ongoing concern. Periodic inspections of roadways and parking lots reveal pavement deterioration; curb damage, and drainage problems. Mobile mapping inspections also identify any required maintenance of signage, markings / striping, light poles, and other related items. In addition, the owner has a complete 3D visual and geospatial record of the facility life-cycle over time.
From my perspective, these few examples of the application of mobile LiDAR to site work, road construction, and project management are just the tip of the iceberg for the New Year of 2011. Surveyors, Engineers, and Contractors are some of the most inventive people on this planet, and quick to take advantage of any technology that improves their performance and efficiency. Stay tuned for further developments in this area.