渤海近岸水体后向散射系数反演模型

水体后向散射系数bb是重要的海洋光学参数,在以悬浮物为主要组分的浑浊二类水体中,其对于水体光学性质起着决定性的作用,该参数的遥感反演对于海洋光学与水色遥感研究具有重要意义.利用2005年渤海近岸水体实测数据集,建立了基于水体遥感反射率光谱数据的后向散射系数bb(λ)经验反演模型(λ=442 nm,488 nm,532 nm,589 nm,676 nm),经实测数据检验,bb(442)和bb(589)反演平均相对误差约为30%;bb(488)和bb(676)反演半均相对误差优于40%;bb(532)反演半均相埘误差约为57%.通过分析模型对于输入误差的敏感性发现,当输入端引入±5%的误差时,模型反演值的误差波动在绝大多数情形下可控制在±10%以内,模型足稳定可靠的.模型适用于渤海近岸浑浊水体,可用丁水体光学参数的时空分布特征分析以及基丁固有光学参数的水色组分遥感反演.

Backscattering Coefficient Retrieval Model for Nearshore Area of Bohai Sea

Backscattering coefficient is an important parameter in ocean optics and determines to a large extent ocean optical properties of coastal case Ⅱ water, whose dominant constituent is suspended material. The remote sensing retrieval of the backscattering coefficient is important for the research of ocean optics and ocean color remote sensing. Based on in situ data acquired in nearshore area of the Bohai Sea in 2005, the empirical retrieval model for backscattering coefficient bb(λ) (λ=442 nm, 488 nm, 532 nm, 589 nm, 676 nm) based on remote sensing reflectance is developed. The model is validated by in situ data with mean relative errors for bb(442) and bb(589) retrievals about 30%, those for bb(488) and bb(676) better than 40% and that for bb(532) ～57%. Model′s sensitivity to the input error is analyzed by introducing ±5% error of remote sensing reflectance artificially. It′s found that for the majority of different cases of input error, the model is stable and reliable with the output error fluctuation less than ±10%. The model is applicable to the turbid coastal water of the Bohai Sea and could be utilized in the spatio-temporal variation analysis of ocean optical properties as well as optically significant constituents retrievals based on inherent optical properties.