偏振激光雷达探测大气—水体光学参数廓线  

Detecting atmospheric-water optical property profiles with a polarized lidar

作　　者：周雨迪 刘东[1] 徐沛拓 毛志华[2] 陈鹏[2] 刘志鹏[1] 刘群[1] 唐培钧 张与鹏 王雪霁 任佳炜 金时伟 ZHOU Yudi;LIU Dong;XU Peituo;MAO Zhihua;CHEN Peng;LIU Zhipeng;LIU Qun;TANG Peijun;ZHANG Yupeng;WANG Xueji;REN Jiawei;JIN Shiwei(State Key Laboratory of Modern Optical Instrumentation,College of Optical Science and Engineering,Zhejiang University, Hangzhou 310027,China;Second Institute of Oceanography,State Oceanic Administration,Hangzhou 310012,China)

机构地区：[1]浙江大学光电科学与工程学院现代光学仪器国家重点实验室,杭州310027 [2]国家海洋局第二海洋研究所,杭州310012

出　　处：《遥感学报》2019年第1期108-115,共8页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家重点研发计划(编号:2016YFC1400902;2016YFC1400905;2016YFC020070);国家自然科学基金(编号:41775023;61475141);浙江省自然科学基金杰青(编号:LR19D050001)~~

摘　　要：激光雷达在上层水体垂直廓线的遥感中展现出巨大优势。本文研制了一套高垂直分辨率的实时探测偏振激光雷达,提出了一种基于偏振激光雷达回波信号的反演算法,采用Fernald理论和多次散射原理反演非均匀大气—水体的衰减和退偏光学产品,以高效稳定地处理偏振激光雷达实验数据。展示了一个中国内陆水体激光雷达探测实例,观测到了两次气溶胶积聚现象和一次水体浑浊现象。对实验数据的分析表明,退偏比主要由前向多次散射和后向单次散射产生的退偏两部分组成。当多次散射强度较大时,退偏比的变化主要取决于多次前向散射退偏;反之,则主要依赖于单次后向散射退偏。The ocean covers more than 71% of the Earth. Studies on vast oceans are of great significance for resource utilization and climate change. Several methods have been employed to detect the interior of the ocean. In-situ methods can accurately obtain marine information but their efficiency is limited. Ocean color remote sensing can collect global data. However, the limited information about the depth and dependence on natural light restrict its applications. Acoustics are widely used for seawater profiling, but they can only work under water due to the high loss in air–water interface. LiDAR is an effective method used to deal with seawater profiling with few limitations of platforms and natural light, in which its applicable coverage is from the water surface to the depth with several tens of meters. A polarized lidar with high vertical resolution(approximately 0.225 m in the water and 0.3 m in the atmosphere) and real-time detecting capability was developed to detect the profile information of atmospheric-water particulates. The laser was linearly-polarized to obtain the polarized information about the water column. Two refractive telescopes were used to collect the backscattering light from the water.Two polarizers were set in front of the telescopes, which only transmitted return signals that were co-polarized or cross-polarized with the laser. A retrieval algorithm based on polarized lidar returns was proposed to obtain atmospheric-water attenuation and depolarized optical products, such as, extinction coefficient(atmosphere), diffuse attenuation coefficient(water), depolarized ratio(atmosphere and water), forward depolarized coefficient(water), and backward depolarized ratio(water). An experimental sample from the inland water in Xiakou Reservoir, China during the night between April 6 and 7, 2017 was presented to discuss the physical meanings and scientific values of the optical products. The retrieved optical products presented the variation of atmospheric aerosols and water turbidity during the night. Fo

关 键 词：光学遥感 激光雷达 漫射衰减系数 偏振 多次散射 

分 类 号：TN958.98[电子电信—信号与信息处理]