EAGER: Polarimetric-Raman Lidar for Tropospheric Ice and Liquid Water Fractions

拉曼光谱通过分子系统的振动、旋转和低频模式的非弹性散射来探测物质的化学和物理状态。在大气中，最丰富的拉曼散射体之一是水，以冰、液体和蒸汽的形式存在，以及它们的混合物。该EAGER项目旨在提高拉曼光谱与偏振激光雷达（光探测和测距）相结合的可行性，以远程分析对流层气溶胶和云层中水相的比例。该建议符合一个或多个EAGER标准，因为这项工作本质上是探索性的，而且使用近红外傅立叶变换光谱仪（FTS）的特殊方法在理论上能够达到所需的高光谱分辨率，但在这种配置中基本上没有经过测试。在高背景光条件下（例如日光或黄昏），自动照明系统能否令人满意地工作，可能是建议书风险的主要因素。

Raman spectroscopy probes the chemical and physical states of matter through inelastic scattering from the vibrational rotational and low frequency modes of molecular systems. In the atmosphere, one of the most abundant Raman scatterers is water, in its ice, liquid and vapour phases, and in their admixture. This EAGER award seeks to improve the feasibility of Raman spectroscopy combined with polarimetric Lidar (light detection and ranging) to remotely profile the fraction of water phases in tropospheric aerosols and cloud layers. This proposal meets one or more of the EAGER criteria because the work is exploratory in nature and the particular approach, using a near IR Fourier Transform Spectrometer (FTS) theoretically capable of the requisite high spectral resolution, is largely untested in this configuration. The ability of the FTS to perform satisfactorily under high background light conditions (e.g. daylight or twilight) is likely to be a main element of proposal risk.