Using derivative spectrum to estimate suspended sediment concentration of estuarine waters
YU Ding-feng1,2, XING Qian-guo1,3, CHEN Chu-qun3, SHI He-yin4, SHI Ping1,3
1. Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; 2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China; 3. Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; 4. Guangzhou Monitoring Center of Marine and Fisher Environment, Guangzhou 510235, China
Suspended sediments not only influence water quality,but also play an important role in coastline evolution.With the aid of sensors on board buoy,plane and satellite,hyperspectral technique is considered as one promising tool to solve the problems in monitoring optically-complex waters.In order to apply hyperspectral techniques in the in-situ suspended sediment monitoring in estuarine waters,we carried out two cruises in the Pearl River Estuary in May 2004 and August 2006.Water samples were collected at each sampling station simultaneously.The original reflectance spectra with 0.38 nm spectral resolution were re-sampled to 10 nm,and then the first-order and second-order derivative spectra were processed.Correlation analysis was performed between the measured suspended particle matter(SPM) concentrations and each band.The results indicated that first-order derivative spectra,especially at the wavelength of 605 nm,could be used to estimate concentration of SPM at estuarine waters.This suggests a new way for the in-situ suspended sediment measurement and potential application to Hyperion and HJ-1 satellite images in the optically-complex estuarine waters.
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