In our new STEIN series, “Seizing Opportunities,” we share our knowledge about strategies companies can use to achieve long-term success. The first episode focuses on the bird’s-eye view. Drones enable inspections, measurements, and documentation of quarries or facades.
Unmanned aerial vehicles—known as Unmanned Aircraft Systems (UAS) or Unmanned Aerial Vehicles (UAV), and commonly referred to as “drones” or “multicopters”—are now used in numerous areas of construction, renovation, and building preservation. Equipped with a digital or thermal imaging camera or a 3-D laser scanner, remote-controlled drones can inspect or geometrically map quarries, facades, or roof surfaces; locate and document damage; detect energy losses; and much more.
For construction, renovation, or remodeling projects to be successful, they must be carefully prepared and planned. Up-to-date and reliable as-built data is the most important foundation for prudent planning. Terrestrial surveying methods such as tachymetry, laser scanning, or photogrammetry capture only those areas that are accessible and visible from the ground or from surrounding buildings. Roof surfaces and other inaccessible areas of a building’s facade cannot be captured geometrically or photographically, or can only be captured inadequately.
Drones can use aerial photogrammetry or 3-D laser scanners to perform seamless geometric surveys of buildings and other objects, which is why they are sometimes used in parallel: Perspective-corrected aerial images can be used to create roof plans or facade views that are accurate to the centimeter and to scale. When the aerial images are analyzed using photogrammetry, they can be used to create 2-D plans or three-dimensional models of the building envelope. These can serve as a basis for planning, cost estimates, bids, or visualizations.
Drones equipped with special 3-D laser scanners can scan the surrounding area in a grid pattern in a matter of seconds, generating millions of 3-D measurement points—so-called “point clouds.” In the process, they store the geometric data of all surrounding objects as spatial coordinate values. An integrated digital camera also captures 360-degree photo panoramas and maps building envelopes with virtually no gaps. Survey drones are also capable of first capturing orthogonal photos or 3-D laser scans of stockpiles, gravel and crushed stone pits, landfills, or quarries, and then using these to generate 2-D site plans, 3-D terrain models, masses, and volumes—all without disrupting ongoing operations or endangering people.
Read more inSTEIN 8/2020.
