Laser scanning

Laser scanning is a survey method in which the scanner sends out a laser beam and calculates distance from the returning reflection. As the device rotates it measures a huge number of points in a short time, and the result is stored as a point cloud. Static scanners on tripods, mobile systems carried on foot or by vehicle, and airborne LiDAR are all members of the same family.

Where it is used

Surveys of historic buildings, restoration projects, industrial buildings with dense services, and renovations of old buildings with no drawings are the classic cases. A survey that would take days with a tape measure can be captured far faster, including places you could never reach by hand. On site, scanning is also used to check that construction matches the design.

How the process works

A space can rarely be seen in full from one spot, so the scanner is set up at several stations. The scans are then joined using shared targets or surface matching, a step called registration. The combined cloud is cleaned, tied to a coordinate system if needed, and brought into drawing or modeling software.

Laser scanning delivers highly accurate data, but data is not a design. Drawing plans, sections and elevations from the cloud, or building a BIM model, is a separate job. Most scanners also take photos for color, and where texture quality matters, laser scanning is often paired with photogrammetry.