RETRIEVING AND MONITORING SHALLOW WATER DEPTH AND BOTTOM REFLECTANCE IN COASTAL WATERS OF THE SOUTH CHINA SEA ISLAND AND REEFS USING HYPERSPECTRAL AND COASTAL MULTI-SPECTRAL SATELLITE DATA

摘要

Hyperspecral satellite data have been used to simultaneously retrieve shallow water depth, bottom reflectance and water optical properties without any prior knowledge and the accuracy can reach up to 14% in the South China Sea (SCS) , but their application are limited to the few data sources. Multi-spectral satellite data have abundant data sources which can complement hyperspectral data. A new model independent of in situ water depth data for multi-spectral data has been developed and relative error is about 17% when applying in the SCS. In this study, HICO hyperspectral data and Landsat-8/OLI multi-spectral data are used to derive water depth and bottom reflectance around Yongle Group Islands, Huaguang Reef and Panshi Islet in the SCS. The results show that derived water depth agree well each other. Time-series Landsat-5/TM and Landsat-8/OLI data are further used to derive and monitor shallow water depth around Nanxun Reef, Jinghong Island, Nanzi Island, and Yongshu Reef in the SCS.