Inherent optical properties of water measured in situ and from multispectral imageries - A case study on waters south of Singapore

Abstract

The depth of light penetration in water is one important factor that restricts coral growth. The inherent optical properties of water, in particular, the absorption and backscattering coefficients are important quantities that determine the depth of light penetration. Semakau Landfill is an off-shore landfill of Singapore. However, it is also home to rich marine life. It is desirable to monitor the water quality efficiently. We measured the absorption and backscattering coefficients of the waters along the western coast and compared the backscattering coefficients with those extracted from multispectral imageries acquired from Landsat and IKONOS. Our results show that there is little spatial variation in water properties in the small region. Moreover, the particle absorption coefficient is insignificant at 650 nm and 676 nm. This allows us to extract the backscattering coefficients from satellite imageries using a modified version of the quasi-analytical algorithm. The extracted backscattering coefficients agree quite well with the measured values.