摘要
现有水色卫星主要是针对大洋清洁水体设计,内陆浑浊水体多数波段经常饱和;而发展可以业务化运行的内陆水体叶绿素a算法,为生产实践服务,一直是水色遥感的重点和难点之一.利用2013年巢湖星地同步数据(N=55),通过经验正交函数(empirical orthogonal function,EOF)分析方法,选用MODIS唯一不饱和的4个波段(469、555、645、859 nm)数据进行分解,然后回归建模;并使用第三方独立的巢湖实测数据(N=40)进行验证(R2=0.63,URMSE=85.46%).结果表明:该算法用于MODIS影像上,空间分布合理,季节差异明显,且在高悬浮物水体、不同气溶胶条件下均有很好的抗扰动性.实践证明EOF算法可以应用于业务化运行的内陆水体叶绿素a浓度估算,并对其他水色参数反演具有一定的借鉴意义.
Ocean color satellite is mainly designed for oceanic waters, but most of their bands are easily saturated in highly turbid waters. It＇ s a great challenge to monitor water quality using satellites, because there are no operational algorithm to estimate chlo- rophyll-a concentration （ Chl. a） in inland waters. In this paper, a novel approach based on the Empirical Orthogonal Function （EOF） analysis was developed using the spectral variance from the Rayleigh-corrected reflectance data （Rrc） at 469, 555, 645 and 859 nm, and Chl. a was estimated by considering the regression relationships between the spectral variance and 55 concurrent field ts. The validation was then performed using independent data （N = 40） from other laboratory, with R2 = 0.63 URMSE = 85.46%. Application of the algorithm to MODIS images showed that spatial distribution patterns and seasonal changes are reasonable. Besides, this algorithm is immune to perturbations from thiek aerosols and different sediments. Henee, we suggest that EOF algorithm could be applied to estimate Chl. a concentrations in inland waters.
出处
《湖泊科学》
CAS
CSCD
北大核心
2015年第6期1140-1150,共11页
Journal of Lake Sciences
基金
国家高技术研究发展计划”863”项目(2014AA06A509)
国家自然科学基金重点项目(41431176)联合资助
关键词
业务化运行
叶绿素A
MODIS
经验正交函数
内陆水体
巢湖
Operational algorithm
chlorophyll-a
MODIS
empirical orthogonal function
inland water
Lake Chaohu
