Types of measures
Terrestrial Laser Scanners. Some Clouds for the Geomatic

Although there are many different models of terrestrial laser scanners, the basic operating principle is the same for all of them:

• a motor for controlled rotation around the instrument's main axis (usually almost vertical);

• in parallel, a system of mirrors or prisms rotates about an axis perpendicular to the first ;

• a laser pump emits a beam which, using different techniques, provides distance information;

• we'll also store the intensity of the return signal.

It is possible to determine the three-dimensional position of the impact of the emitted beam in a reference frame local to the scanner position with the polar information shown in figure