Aerosol Mapping Using a Bistatic Camera Lidarand Comparing with Radiosonde Data in the Bahamas

摘要

A camera based bistatic lidar (CLidar) is used to profile aerosols in the atmosphere of Nassau, Bahamas. In CLidar, a CCD camera fitted with a wide-angle lens is placed several hundred meters away from the vertically transmitted laser to capture the entire beam from ground to zenith. The CCD signal, containing both aerosols and molecular side scattering, is normalized to a model of molecular scattering to retrieve single angle aerosol scattering. Finally, a CALIPSO model aerosol phase function is employed to calculate aerosol extinction and corresponding scattering altitudes are calculated using CLidar geometry. Aerosol extinctions show a significant correlation with radiosonde relative humidity measurements. Excellent CLidar altitude resolution near ground level allowed detection of pollution from local sources. Cloud thickness was retrieved using CLidar extinction. Measurements from three different days show extinction is high near ground level, sharply decreases within the first 60 m and then gradually increases up until 500 meters-above-sea-level.