大气海洋高光谱分辨率激光雷达鉴频特性研究

统一分析大气海洋高光谱分辨率激光雷达(HSRL)的鉴频性能,能够为大气海洋的联合探测研究提供帮助。 提出了一种基于视场展宽迈克尔逊干涉仪(FWMI)鉴频器的大气海洋HSRL系统和算法,用于反演海水和 大气颗粒的180°体积散射系数。该系统的核心在于采用混合-分子双通道接收信号,其中分子通道 利用FWMI鉴频器滤除颗粒信号,透过分子信号。研究表明,反演误差会随着颗粒散射比(总180°体积散射 系数与分子180°体积散射系数之比)增大而线性增大,而光谱分离比(分子与颗粒透过率之比)的提高能够显 著抑制误差的增长趋势。因为海洋的分子散射与颗粒散射在光谱上更加分离,因此FWMI在海洋HSRL上的鉴频 能力高于大气HSRL。所提的基于FWMI的HSRL系统能够工作于水体和大气中,对大气海洋激光雷达的性能提升有重要的意义。

Investigation on Discrimination Characteristics of Atmospheric and Oceanic High-Spectral-Resolution Lidar

The combined analysis of the discrimination performance of the atmospheric and oceanic high-spectral-resolution lidar (HSRL) can help the joint atmospheric and oceanic observation research. An atmospheric and oceanic HSRL system based on the field-widened Michelson interferometer (FWMI) discriminator is proposed in this work, which can be used to retrieve the 180-degree volume scattering function of oceanic and atmospheric particles. The core of the system is the combined-molecular dual channel, in which the molecular channel uses FWMI discriminator to filter the particle signal but transmit the molecular signal. It is shown that the retrieval error will increase proportionally with the particulate scattering ratio (the ratio of the total 180-degree volume scattering function to that of molecular), while the enhancing of the spectral discrimination ratio (the ratio of the molecular transmittance to the particulate transmittance) can significantly suppress the growth trend of the retrieval error. Because molecular scattering and particulate scattering are separated in the spectrum of oceanic HSRL, FWMI has a better discriminating characteristics in the oceanic HSRL than in the atmospheric HSRL. The proposed HSRL system based on FWMI can work in water and atmosphere, which is of great significance to the performance improvement of atmospheric and oceanic lidar.