Transmitted beam profiles, integrated backscatter, and range-resolved backscatter in inhomogeneous laboratory water droplet clouds

Abstract
Using laser sources at wavelengths of 1.06 and 10.6 µm, transmitted beam profiles, integrated backscatter, and range-resolved backscatter were measured in laboratory-generated water droplet clouds. Clouds with carefully controlled properties were produced in a specially designed cloud chamber. Inhomogeneities were introduced by partitioning the cloud chamber into three adjacent sections separated by air screens. The measurements show the influence of multiple-scattering effects in both the forward and backward measurement geometries, and these are investigated as functions of optical depth, cloud inhomogeneity, and receiver field of view. These data are unique in many ways, and they provide a great deal of insight to the scattering processes which directly affect lidar-type measurements. As well, these measurements provide a welldocumented and detailed database for model validation. Very good agreement is demonstrated with the solutions derived from the multiscattering propagation model described in a companion paper [Appl. Opt. 27, 2478 (1988), same issue].