Doppler LIDAR Developments for Aeronautics

ideal tools for remote wind measurements. LIDARs emit beams of monochromatic light toward the desired measurement area in the atmosphere. Photons are scattered along the beam by dust particles (Mie scattering) and molecules (Rayleigh scattering) contained in the air. A very small fraction of light is 180°-backscattered toward the laser emitter, beside which a receiver is placed. Particles (and molecules) are so light that their movement perfectly follows air motion and they can be used as air speed tracers. Due to the air mass motion relative to the LIDAR emitter/receiver, backscattered light collected by the receiver is frequency-shifted by the Doppler effect by a quantity The paper presents some of the recent Doppler LIDAR developments at ONERA. Some insight into state-of-the-art technology is provided, as well as perspectives for future applications in aeronautics.