Concept Design of a Multiwavelength Aerosol Lidar System With Mitigated Diattenuation Effects and Depolarization-Measurement Capability

Abstract

It is known that the retrieval of aerosol extinction and backscatter coefficients from lidar data acquired through so-called total-power channelsintended to measure the backscattered power irrespective of the polarization -can be adversely affected by varying depolarization effects produced by the aerosol under measurement. This effect can be particularly noticeable in advanced multiwavelength systems, where different wavelengths are separated using a system of dichroic beam splitters, because in general the reflection and transmission coefficients of the beam splitters will be different for fields with polarization parallel or perpendicular to the incidence plane. Here we propose a setup for multiwavelength aerosol lidars alleviating diattenuation effects due to changing depolarization conditions while allowing measure linear depolarization.

An Architecture Providing Depolarization Ratio Capability for a Multi-Wavelength Raman Lidar: Implementation and First Measurements

“…The aerosol depolarization ratio measurement requires the comparison of the signals recovered by two channels in the system: one proportional to the total power and another proportional to the cross-polar component of the collected light [ 38 , 39 ]. These two channels operate at 532 nm.…”