AIAS is a mobile depolarization lidar employed for detecting the polarized and cross polarized backscattered lidar signals at 532 and 1064 nm, to further characterize the shape of the sampled particles and cloud properties (water- or mixed-phase clouds). It provides the vertical profiles of the aerosol backscatter coefficients at 532 and 1064 nm, the linear particle depolarization ratio (LPDR) at 532 nm, as awell as the cloud geometrical properties, from 0.3 up to 8-10 km asl., with a high temporal (1.5 min) and spatial (down to 7.5 m) resolution. The calibration technique applied in this system is the ±45o calibration method as performed in the frame of the European Lidar Network (EARLINET).