双波长海洋激光雷达探测近岸到大洋水体的叶绿素剖面  

Detection of Chlorophyll Profiles from Coastal to Oceanic Water by Dual-Wavelength Ocean Lidar

作　　者：李凯鹏 贺岩[1] 侯春鹤 马剑[1] 姜正阳 陈卫标[1] 陈鹏 刘芳华 陈勇强 郭守川 Li Kaipeng;He Yan;Hou Chunhe;Ma Jian;Jiang Zhengyang;Chen Weibiao;Chen Peng;Liu Fanghua;Chen Yongqiang;Guo Shouchuan(Key Laboratory of Space Laser Communication and Detection Technology,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou,Zhejiang 310012,China)

机构地区：[1]中国科学院上海光学精密机械研究所空间激光信息传输与探测技术重点实验室,上海201800 [2]中国科学院大学材料与光电研究中心,北京100049 [3]自然资源部第二海洋研究所卫星海洋环境动力学国家重点实验室,浙江杭州310012

出　　处：《中国激光》2021年第20期142-152,共11页Chinese Journal of Lasers

基　　金：自然资源部第二海洋研究所卫星海洋环境动力学国家重点实验室重点研发项目(2016YFC1400902);青岛海洋科学与技术国家实验室区域海洋动力学与数值模拟功能实验室开放基金项目(2018SDKJ0102-7)。

摘　　要：蓝绿激光波段作为海洋主动探测技术中常用的波段,被广泛应用于各种海洋激光雷达设备中。然而由于近岸水体和大洋水体的水质参数不同,不同水体对蓝光和绿光的衰减存在差异。通过反演双波长海洋激光雷达(DWOL)系统中486 nm蓝光通道和532 nm绿光通道在南海获取的近岸水体和大洋水体探测的波形数据,结果表明:在清洁大洋水域中,486 nm通道的水体衰减系数明显小于532 nm通道,由此说明蓝光更适用于大洋清洁水体探测;在近岸水域中,由于水质变差,486 nm通道和532 nm通道的衰减系数差异减小,同时考虑到532 nm激光的稳定性和低成本,可知绿光更适用于近岸水体探测。另外,为了分析南海水域次表面层叶绿素散射层(CSL)从近岸水体到大洋水体的分布变化,基于486 nm通道数据,反演了从清洁大洋水域到近岸水域近120 km连续条带的机载数据。反演结果表明:在大洋水体中,CSL深度稳定分布在水下60 m左右;在临近近岸时,由于水深变浅,CSL深度分布开始快速上升;在近岸水体中,CSL深度上升到水下40 m,甚至到20 m左右。分析船测实验数据与机载反演数据的相关关系,可知机载反演结果和船测结果具有良好的一致性。Objective Marine phytoplankton is crucial to the marine ecosystem due to their important roles in the global primary carbon cycle.They can also be used as an evaluation criterion of water property because of their correction to the watercolor remote sensing parameters.Two detection schemes are often used to obtain the distribution of subsurface phytoplankton,including passive remote sensing technology,such as ocean color remote sensing technology,and activity detection technology,for instance,ocean lidar.The ocean color remote sensing is a practical approach to detecting chlorophyll-a(Chl-a)which is a proxy of phytoplankton.However,as a passive remote sensing scheme,the ocean color remote sensing system can only obtain the integral information of upper waters.The vertical distribution of subsurface phytoplankton in the ocean is significantly important for ocean remote sensing study.To obtain the depthresolved profiles of Chl-a concentration,it is necessary to use the active detection system,such as the ocean lidar system.The conventional ocean lidar systems are often equipped with 532nm lasers;the 532nm laser is robust and cost effective and can penetrate ocean water with high-energy pulses.However,a blue laser penetrates and detects clean ocean waters better than a green laser with the same pulse energy.This study presents a novel dual-wavelength ocean lidar(DWOL)system equipped with a dual-wavelength laser,which can emit 532 and 486 nm lasers simultaneously.An airborne experiment and a shipborne in-situ experiment were conducted in the South China Sea to validate the performance of DWOL;the airborne data has been processed to inverse the vertical Chl-a concentration.We hope that our novel DWOL system can be useful in researching the vertical distribution of the subsurface phytoplankton concentration in the South China Sea.Methods The flying speed was around 55m/s;given that the repetition rate of the laser is 100Hz,500frames of airborne data obtained in 5swill be accumulated to extend the dynamic range of the d

关 键 词：遥感 双波长激光雷达 叶绿素散射层 激光雷达反演 Klett方法 

分 类 号：O439[机械工程—光学工程]