The information content of lidar returns from warm clouds is investigated u
sing a one-parameter model of cloud scattering pattern and the multicompone
nt approach to the solution of the radiative transfer equation. A lidar ret
urn from a cloud is subdivided into the diffraction and geometrical-optics
components formed by the corresponding components of the cloud scattering p
attern. It is shown that only the diffraction component depends on paramete
rs of cloud microstructure, the efficient radius of cloud droplets being th
e most significant parameter in the size distribution of particles. Ways of
optimizing parameters are suggested for lidar stations with circular recep
tion or lidar stations measuring the angular distribution of brightness in
the receiving plane to increase the dependence of receiving signal on the e
ffective radius of cloud droplets.