LiDAR stands for “light detection and ranging,” a technology able to create an interactive topographic map by scanning the earth with lasers. It is similar to sonar in that it measures distance by the time it takes for the laser to reach the ground and bounce back to the source. While laser scanning is routinely done from ground-based locations, aircraft are being used more and more to increase coverage. As a supplement to field surveys, LiDAR is useful in planning for corridor projects such as road construction but can be a valuable adjunct to overall project management as well.
Studies show that for large construction projects, a significant amount of effort is devoted to keeping track of where things are on the site and monitoring the status of construction activity. The upshot of this, as you are well aware, it that the timely knowledge of project status—where things are, what has been done, what needs to be done—is the single most important issue facing construction managers today. OK, you say, but is there a way to accomplish this without affecting the workflow or breaking the bank?
The emergence of scanning lasers has made real-time updates and earthwork calculations of the construction site a viable technique. The gathering of data is nonintrusive and will not impede the construction progress. The scanned data are imported and then processed to provide a constant update allowing
* real-time assessment of construction progress;
* remote monitoring of construction by design engineers, project managers, architects, etc.;
* early detection of errors in construction procedure resulting in cost savings;
* obtaining as-built models of terrain and structures; and
* improved project planning and documentation.
Recent experience shows that calculation of cut-and-fill requirements can be done semi-automatically and 3D graphical representations of the terrain can be done using commercially available software.
We’ll be focusing attention on LiDAR scanning in upcoming issues of Grading & Excavation Contractor, but in the meantime you might want to talk with your laser/GPS system provider about its potential value.