摘要
中国近岸水体泥沙含量较高,且变化梯度大;泥沙浓度可从几千mg/l变化到1mg/l以下。针对上述浑浊二类水体的大气修正一直是水色遥感应用的难点之一。利用水体近红外固有光学特性的Arnone光谱迭代算法在泥沙含量较低时适用,其近红外光谱迭代关系与根据2003年春季黄东海水色试验数据得出的现场光谱关系大致相当。当泥沙含量达到某一程度时,该算法失效,导致蓝光等较短波段的离水辐亮度为负。根据现场数据分析结果,这一分界点大概在泥沙浓度10—20mg/l。因此,本文首次提出将中国近岸浑浊水体进一步区分为中低和中高浑浊水体,并给出初步的划分标准,采用光谱优化方法对中高浑浊水体进行水色大气修正。优化误差函数的选取以现场试验获取的可见光波段光谱关系式为基础。结果表明,优化算法在近岸高浑浊水体可给出满足光谱分布规律的反演结果。与其他大气校正方法一样,优化方法也需要进一步的微调。将Gordon标准算法、Arnone光谱迭代和优化方法结合,对SeaW iFS图像进行处理,分别得出归一化离水辐亮度和总悬浮物(TSM)浓度分布图像,结果令人满意。
The suspended matter concentrations are very high in coastal waters of China, and the variations of concentrations gradients are also great. The concentrations may vary from several thousands mg/l to less than l mg/l. Atmospheric correction for above turbid waters has been always the unsolved problem in ocean color remote sensing. The Arnone iteration method using inherent optical properties of near-infrared （NIR） bands is just applicable in lowly turbid waters, whose spectral relations between red and NIR bands are mostly similar to that derived from ocean color experiment data in Yellow Sea and East China sea, spring, 2003. But the iteration method failed, and the water-leaving radiances at shorter bands such as blue bands are negative, when the suspended matter concentrations exceed 10--20mg/l, which is the result of in situ data mentioned above. Therefore, in this article we distinguish turbid waters into low and high turbid waters .and give the preliminary criterion. Optimization method has been applied to atmospheric correction of highly turbid waters whose error function is determined by spectral relations between various visible bands from above in situ data. The results show that the optimization method could get reasonable water-leaving radiances, although it needs further finetuning. The normalized water-leaving radiances and total suspended matter concentrations derived from SeaWiFS are mostly satisfied when Gordon standard algorithm, Arnone iteration method and ootimization are used in atmospheric aorrection.
出处
《遥感学报》
EI
CSCD
北大核心
2006年第5期732-741,共10页
NATIONAL REMOTE SENSING BULLETIN
基金
HY-1卫星地面应用系统辐射校正与真实性检验分系统项目
国家863计划课题(2001AA636010)
遥感科学国家重点实验室开放基金(编号:LRSS0604)
中国科学院百人计划项目(编号:KZCX0415)
国家教育部留学回国人员科研启动基金重点项目(编号:HX040013)
国防科学技术工业委员会项目(编号:KJSX0401)
关键词
大气修正
水体浑浊度
泥沙浓度
光谱迭代
优化
atmospheric correction
turbidity
suspended matter concentration
spectral iteration
optimization
