Terrestrial Laser Scanning (or time-of-flight scanning) is a survey method in which an instrument emits a laser beam, which, controlled by motors and mirrors, rapidly scans across an object or surface. It creates a detailed representation of the object in the form of a ‘point cloud’ of millions of 3D points. Each point is measured to 3mm accuracy with a resolution of approx 5mm. Depending on the instrument specification the scan rate (point per second) will normally range from 3,000 – 12,000, with the latest available models approaching 50,000.

However this is a fast developing technology, with the specifications of the instruments, and the functionality of the software rapidly improving.

As explained in Heritage3D guidance on laser scanning this type of scanner is just one of a number of 3D scanning devices. Other systems exist such as triangulation scanners, structured light scanners designed for the purpose of recording artefacts and objects to a much higher precision (microns).