A method is described for the characterization of atmospheric particles by means of a lidar device. The method provides to send a laser pulse in the atmosphere, a part of which is directly backscattered by the particles in the atmosphere. A reflecting optical device is provided, that is positioned at a predetermined distance d from the lidar device, whereby a part of the laser pulse that directly reaches the reflecting device is backreflected and is later backscattered by the particles in the atmosphere thus generating a counterpropagating backscattering signal directed towards the reflecting device, which signal reaches the reflecting device and is backreflected towards the lidar device. The lidar device detects the direct backscattering and counterpropagating signals. The optical characteristics of the particles are determined on the basis of the direct backscattering signal and the counterpropagating backscattering signal.