We report the upgraded version of two compact, airborne, automatic lidars, installed on the stratospheric research aircraft M55 "Geophysica". The lidars (named MAL1 and MAL2) are depolarisation backscatter instruments. They are installed on the aircraft for probing independently upwards and downwards with respect to the aircraft altitude, providing the possibility to detect the cloud presence simultaneously above and below the aircraft. The cloud parameters determined from the lidar signals are the followings: the altitude of the cloud base and cloud top, the backscatter ratio and the depolarisation ratio of the subvisible clouds. The measurements are at a single wavelength of 532 nm (the second harmonics of the Nd:YAG laser). The combination of the photon counting signal acquisition system, the pulse duty cycle and the output power of the micro-pulsed laser, leads to a high dynamic range of detection. Objectives of the lidar installation on this stratospheric aircraft are the measurements of high-altitude cirrus and polar stratospheric clouds, as well as aerosol layers in the middle and high troposphere. We present examples of measurements of backscatter and depolarisation ratio of sub-visible clouds performed with these lidars, during recent field campaigns: ESA ENVISAT Validation and EC projects EUPLEX (European Polar Stratospheric Clouds and Lee Wave Experiment). and TROCCINOX (Tropical Convection, Cirrus and Nitrogen Oxides Experiment).