基于拉曼光谱的海水温度与盐度同步测量方法  

Synchronous Measurement Method of Seawater Temperature and Salinity Based on Raman Spectrum

作　　者：董睿 叶旺全 桂斌 陈宇[1] 卢渊[1] 郭金家[1] 郑荣儿[1] Dong Rui;Ye Wangquan;Gui Bin;Chen Yu;Lu Yuan;Guo Jinjia;Zheng Ronger(Faculty of Information Science and Engineering,Ocean University of China,Qingdao 266100,Shandong,China)

机构地区：[1]中国海洋大学信息科学与工程学部,山东青岛266100

出　　处：《光学学报》2024年第18期202-212,共11页Acta Optica Sinica

基　　金：国家重点研发计划(2016YFC0302101);山东省重点研发计划(2019JZZY010417)。

摘　　要：海洋极端环境如热液、冷泉区高空间梯度的海水温度与盐度测量对研究海洋地质活动及物质循环有着重要的意义。传统的温度与盐度探头难以获得高空间分辨率的温度与盐度同步数据,而基于拉曼光谱和温度与盐度的相关性进行非接触探测可有效实现温度与盐度的同步测量。首先,利用Levenberg-Marquardt方法将拉曼光谱分解得到5个高斯子峰,利用子峰各自携带的峰高、峰宽,以及峰位等特征信息作为训练特征,结合偏最小二乘回归(PLSR)、最小绝对收缩和选择运算符(LASSO)回归等机器学习方法进行训练;然后,采用Stacking集成学习模型对多个学习器进行模型融合,获得温度与盐度同步标定模型。结果显示,提出方法对温度的同步预测均方误差E_(MS)为0.23℃,对电导率(盐度)的同步预测均方误差E_(MS)为1.63 mS/cm。相较于单个子学习器以及单独引入的深度学习模型所预测的结果均有一定的提升。结果验证了拉曼光谱分解子峰同步预测海水温度与盐度的可行性,在深海极端环境探测领域具有一定的应用前景。Objective The monitoring of temperature and salinity(electrical conductivity)in seawater is of significant importance for understanding and predicting the responses of marine ecosystems,hydrological cycles,climate change,and the sustainable utilization of marine resources.The high spatial gradient characteristics of extreme environmental regions,such as hydrothermal or cold seep areas,pose new requirements for in situ measurements of temperature and salinity.Traditional conductivity,temperature,and depth(CTD)equipment,based on contact measurement,cannot achieve high spatial resolution simultaneous measurement of temperature and salinity,nor perform simultaneous measurement of temperature and salinity at a single point.It has been proven that the Raman spectrum of water exhibits a clear linear relationship between temperature and salinity.Raman spectrum can offer non-contact measurements and simultaneous detection of various water parameters.These capabilities provide the potential for measuring temperature and salinity in extreme submarine environments.In this study,we aim to achieve fast,accurate,and real-time in situ detection of seawater temperature and salinity using the Raman spectrum.Methods A 532 nm excitation optical setup(Fig.2)is established in the laboratory to acquire Raman spectra of OH bonds at different temperatures and salinities.Simulated seawater samples are prepared with varying concentrations of NaCl,and their salinities are measured using a conductivity meter.Temperature control is achieved using a Peltier-based cuvette holder for precise temperature regulation.A total of 170 sets of Raman spectra are obtained(Tables 1 and 2),divided into training and prediction sets at a ratio of 7∶3.The acquired Raman spectra are baseline subtracted and normalized for consistency.The Levenberg-Marquardt(L-M)method is employed to decompose the Raman spectra into five Gaussian peaks(Figs.3 and 4).The extracted peak heights,widths,and positions of these Gaussian peaks are used as training features,in conjunc

关 键 词：拉曼光谱 海水温度与盐度 谱峰分解 Stacking集成学习 

分 类 号：O561.3[理学—原子与分子物理]