利用海洋卫星HY-1数据反演叶绿素a的浓度

Retrieval of chlorophyll a concentration from ocean satellite HY-1

利用去包络线法分析了叶绿素的光谱特征,构造了一种新的指数NDPI(Normalized Difference Pigment Index)反映海洋中的浮游植物.以辽东湾为研究区,通过我国第一颗海洋水色卫星HY-1数据获得NDPI值,再根据实测数据建立了叶绿素a浓度反演模型.和波段比值法及类似SeaWiFS的OC4v4算法比较,NDPI算法优势明显,算法稳定.根据该算法反演整个海区的叶绿素a分布,和前人的现场调查有很好的一致性.结果表明HY-1可用于海洋叶绿素反演,用NDPI算法能获得实时大面积海域叶绿素a浓度.

Retrieval of chlorophyll a concentration from satellite HY-1 was carried out for assessment of marine environmental pollution, especially for algae bloom forecasting and monitoring. Spectral feature of chlorophyll was analyzed using spectrum continuum removal and a new Normalized Difference Pigment Index （NDPI） was constructed to indicate the phytoplankton. For the studying area of Liaodong Gulf, NDPI was obtained from the first ocean satellite HY-1 of China. Then chlorophyll a retrieval algorithm was established based on the correlation between NDPI and in situ chlorophyll a concentration. Comparison shows that NDPI algorithm performed better than band ratio algorithm and modified SeaWiFS OCAv4 algorithm and it was stable. Retrieved chlorophyll a concentration from HY-1 using NDPI algorithm shows good consistency with previous field survey. The result demonstrates that HY-1 can be used to retrieve chlorophyll concentration and NDPI algorithm can obtain real-time and large-scale chlorophyll a information in sea area.