Laser scanners capture data by successively considering points on a discrete, regular (typically spherical, cylindrical or line) raster, and recording the respective geometric and radiometric information. Generally, a laser scanner illuminates a scene with modulated laser light and analyzes the backscattered signal. More specifically, laser light is emitted by the scanning device and transmitted to an object. At the object surface, the laser light is (partially) reflected and, finally, a certain amount of the laser light reaches the receiver unit of the scanning device. The measurement principle is therefore of great importance as it may be based on different signal properties such as amplitude, frequency, polarization, time, or phase. Many scanning devices are based on measuring the time t between emitting and receiving a laser pulse, i.e., the respective time-of-flight, and exploiting the measured time t in order to derive the distance r between the scanning device and the respective 3D scene point. Alternatively, a range measurement r may be derived from phase information by exploiting the phase difference Δφ between emitted and received signal. In general, laser scanners may be categorized with respect to laser type, modulation technique (continuous-wave (CW) laser, pulsed laser), measurement principle (time-of-flight, phase difference), detection technique (coherent detection, direct detection), field-of-view (line scanner, pushbroom scanner, array scanner), measurement range (far range, medium range, close range), or configuration between emitting and receiving component of the device (monostatic system, bistatic system). Furthermore, different types of laser scanners may be used for different application scenarios relying on e.g. spaceborne laser scanning, airborne laser scanning, mobile laser scanning, terrestrial laser scanning, underwater laser scanning or bathymetric laser scanning.