Lidars are widely used for investigations of dense atmospheric objects (fogs, clouds, smoke trails.) both for the needs of meteorology and ecology. The polarization studies give additional information about the optical and microphysical properties of the observed objects and phenomena. Two main factors determine the polarization state of the backscattered laser radiation: the shape and size of the scattering particles and the multiple scattering effects. The present work aims at determining the prevailing contribution of one of the factors in different atmospheric situations. Radiative fog and Sc clouds have been investigated by means of polarization aerosol lidar. The multiple scattering contribution was studied by varying the viewing angle of the lidar. On the basis of the lidar data an empirical relation is proposed describing the dependence of the lidar signal depolarization on the viewing angle. On the basis of the particular depolarization coefficient values obtained conclusion is drawn up about the phase composition of the cloud formations.
|Number of pages||5|
|Journal||Proceedings of SPIE|
|Publication status||Published - 1999|