Lidar equation taking account of polarization, second order scattering and travelling time effects

For a homogeneous atmosphere, a theoretical model describing the backscattered signal from a polarized laser pulse is presented which includes primary and secondary scattering and the travelling time effects conditioned by the spatial and temporal shape of the laser pulse as well as by the field of view of the telescope. In particular the temporal course of the backscattered signal parallel and perpendicular to the polarization plane of the laser is analyzed and compared to measurements in the urban atmosphere of Karlsruhe. Conclusions on the type and size of aerosols, and on primary and higher order scattering can be drawn from the present model as opposed to the lidar equation used so far. With regard to rain clouds the experimental results agree widely with the present signal model.