Retrieving Water Depth, Inherent Optical Properties and Bottom Reflectance by Spectrum Matching in Turbid Coastal Waters

In this paper, we implemented a spectrum matching method for retrieving the inherent optical properties, water depth and sea bottom reflectance from measurements of remote sensing reflectance for turbid coastal waters. In the spectrum matching method for inversion, a database of reflectance spectra for various water conditions is first generated. The measured reflectance spectrum is then compared with each computed spectrum in the database. The water conditions corresponding to the best-match spectrum in the database is taken as the solution of the inverse problem. For water depths between 3.0 and 5.0 m, the absolute error of depth retrieval was about 0.35 m. The retrieved absorption coefficients at 412 nm were within 32% of the measured ones while the scattering coefficients at 555 nm were within 34%. The retrieved bottom reflectance spectra was similar to that of a sandy surface.