3D laser scanning / digitising is a technology that captures the digital shape of physical objects.Its use can decrease engineering costs, allow reverse engineering, shorten programmes, generate “as-built”documentation and provide a whole new perspective to projects.
How 3D Laser Scanning Works
Laser scanning technology is referred to as "terrestrial laser scanning" or "high definition surveying" and is a precise method of 3D data acquisition. The tripod mounted scanner emits a narrow laser beam to scan objects of interest, producing a 360 degree three dimensional "point-cloud" of survey information.
Sweeping its beam (using internal mirrors and motors) over the surrounding scene, virtually blanketing the selected scene with laser measurements. As the beam hits objects in the surrounding area the laser light is reflected back to the scanner. The scanner detects the return signal and calculates a distance measurement.
Combining these distance measurements with internal angle measurements of the scanner's rotating mirrors, relative X, Y, Z co-ordinates can be established for each point on a surface that the beam hits. A laser scanner collects hundreds of thousands of closely spaced surface geometry measurements (points), to high accuracy, in just minutes. These surface points can then be displayed on a computer system; the resulting "point cloud" looks like a dense, 3D bit-map image of the surveyed area. It can be viewed and navigated much like a 3D model. However, each of these scanned points is not simply a "dumb" pixel, it has true site X, Y and Z coordinates that can be interrogated.
What is 3D Laser Scanning used for ?
3D laser scanning is commonly used to accurately capture and store "as-built" or "existing" information, often from safe remote locations, to assist the design process. From mechanical plant to buildings and structures, its function is always the same; to record and transfer the survey area into a digital computer format that can be successfully interrogated remotely.
For example, the 3D model would offer not only infinite viewpoint options but can be sliced horizontally for plan presentation or sliced vertically for sectional information.Utilising specialist software allows us to cross-examine this data to establish inaccessible pipework/equipment centre lines/details remotely without requirement for scaffolding, plus the ability to model these areas for export or cross/clash check against other CAD systems.
Quality, Accuracy & Efficiency
Laser scanning offers an ideal input for designing modificationsto existing sites or facilities. Clash detection within the software ensures that component conflicts can be avoided during design. Due to its ability to quickly record even the most complex arrangements within a potentially hazardous process installation, with both range and accuracy, 3D laser scanning has proved its potential to add value to Projects.
