二类水体吸收系数精确校正及其遥感反演研究

发布时间：2018-03-28 22:05

本文选题：二类水体　切入点：吸收系数　出处：《中国科学院大学(中国科学院遥感与数字地球研究所)》2017年博士论文

【摘要】：水体对光的吸收在水体光衰减、混合层加热、初级生产力、浮游植物生物量等的时空分布变化中扮演重要角色。定量获取水体吸收系数主要有三种方法:现场原位仪器测量、实验室过滤水样分析和反射率遥感反演。由于我国近海二类水体光学特性复杂且时空分布变化大,水中物质在近红外波段存在显著吸收,主要成分浮游植物的吸收光谱受包囊效应和色素组成等因素影响,降低了获取吸收系数的精度,研究这些问题对提高水色吸收系数精度和水色遥感具有现实意义。1)近海水体光学特性时空分布方面,通过对黄海不同季节六个航次的现场数据进行水体分类研究,分析了遥感反射率光谱的分类特征,获取了黄海水体光学特性和时空分布特征。黄海水体光谱分类算法应到MERIS业务卫星,获得长时间序列不同时空下黄海水体光学分布特征及变化规律。2)野外原位测量吸收系数方面,改进一种基于E指数拟合获得散射项系数的散射校正方法,对九波段吸收衰减仪器(AC9)各吸收波段进行散射校正,满足在近海和内陆典型水体应用。结果与其他常用的校正方法比较,在红光和近红外波段有较明显抬升。结果与实验室测量的吸收系数具有可比性,可用于闭合检验。3)实验室测量的浮游植物吸收系数方面。本文利用黄东海2003年春季和秋季航次测量的色素浓度和浮游植物吸收光谱数据,通过去包囊效应,对吸收光谱数据进行特征波段高斯分解和色素成分分解和重构模拟研究,高斯分解的残差值多小于0.001 m-1,成分分解值与实测色素浓度接近,但存在明显季节性偏差。4)在遥感反演获得吸收系数方面,半分析算法能一定程度反演黄渤海水体的总吸收系数与后向散射系数,但浮游植物主导和近岸高浑浊水体反演结果相对偏差较大。用实验室测量吸收对算法进行改进,使得黄渤海各波段吸收系数反演精度显著提高,使用现场原位测量的吸收系数对改进算法检验,结果较好。本文的研究成果可以广泛应用于近海水体吸收特性研究,还可用于全球陆架海区上层海洋的生态和生物地球化学重要特性研究。
[Abstract]:The absorption of water light plays an important role in the temporal and spatial distribution of water light attenuation, mixed layer heating, primary productivity and phytoplankton biomass. Laboratory filtered water sample analysis and reflectivity inversion. Due to the complexity of optical properties and the large changes in spatial and temporal distribution of the second class of offshore water bodies in China, there is a significant absorption of substances in water in the near infrared band. The absorption spectra of phytoplankton are affected by the cyst effect and pigment composition, which reduce the precision of obtaining absorption coefficient. The study of these problems is of practical significance for improving the accuracy of water color absorption coefficient and water color remote sensing. 1) the temporal and spatial distribution of optical properties of offshore waters is studied. The classification of water bodies is carried out on the basis of the field data of six voyages of Huang Hai in different seasons. The classification characteristics of remote sensing reflectance spectrum are analyzed, and the optical characteristics and spatio-temporal distribution of Huang Hai water body are obtained. Huang Hai water body spectral classification algorithm should be applied to MERIS service satellite. In order to obtain the optical distribution characteristics and variation law of Huang Hai water body in different time series in long time series. 2) in the field measurement of absorption coefficient, an improved scattering correction method based on E exponent fitting to obtain scattering term coefficient is improved. The absorption attenuation instrument AC9) has been corrected by scattering in each absorption band to satisfy its application in typical offshore and inland water bodies. The results are compared with other commonly used correction methods. There is a significant uplift in the red and near infrared bands. The results are comparable to the absorption coefficients measured in the laboratory. In this paper, the pigment concentration and phytoplankton absorption spectra measured in spring and autumn of 2003 in the Yellow Sea and East China Sea are used to measure the absorption coefficient of phytoplankton in laboratory. The characteristic band Gao Si decomposition and pigment component decomposition and reconstruction simulation of absorption spectrum data were carried out. The residual value of Gao Si decomposition was less than 0.001 m ~ (-1), and the component decomposition value was close to the measured pigment concentration. But there is obvious seasonal deviation. 4) in the aspect of remote sensing inversion to obtain absorption coefficient, the semi-analytical algorithm can retrieve the total absorption coefficient and backscattering coefficient of the Yellow Sea and Bohai Sea to some extent. But the relative deviation between phytoplankton dominant and near-shore high turbidity water inversion results is large. The algorithm is improved by laboratory measurement and absorption, which makes the retrieval accuracy of absorption coefficients in each band of the Yellow Sea and Bohai Sea significantly improved. The results of this paper can be widely used in the study of the absorption characteristics of offshore water bodies, and the results obtained in this paper can be widely used in the study of the absorption characteristics of offshore water bodies. It can also be used to study the ecological and biogeochemical characteristics of the upper ocean in the global shelf area.
【学位授予单位】：中国科学院大学(中国科学院遥感与数字地球研究所)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P733

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