Retrieval of cloud optical parameters from space-based backscatter lidar data.

We present an approach to estimating the multiple-scattering (MS) contribution to lidar return signals from clouds recorded from space that enables us to describe in more detail the return formation at the depth where first orders of scattering dominate. Estimates made have enabled us to propose a method for correcting solutions of single-scattering lidar equations for the MS contribution. We also describe an algorithm for reconstructing the profiles of the cloud scattering coefficient and the optical thickness tau under conditions of a priori uncertainties. The approach proposed is illustrated with results for optical parameters of cirrus and stratiform clouds determined from return signals calculated by the Monte Carlo method as well as from return signals acquired with the American spaceborne lidar during the Lidar In-Space Technology Experiment (LITE).

Noise-proof inversion of lidar equation.

The reasons for instability of the lidar equation solution are investigated. An effective method of recovering the attenuation coefficient profile and transmittance of an optically thick atmosphere from the data of single-frequency laser sounding is suggested. The method enables one to obtain stable solutions of the lidar equation for sounding paths adjacent to the horizontal ones withoutthe use of absolute calibration of the lidar. A comparison is made with the known algorithms of processing. The results of experimental tests of the method when sounding fogs in the boundary atmospheric layer are described.