Retrieval of Particle Scattering Coefficients and Concentrations by Genetic Algorithms in Stratified Lake Water

We retrieved the mass-specific scattering coefficient b(sm)*(lambda) = 0.60.(lambda/650)(-1.82) of the inhomogeneous and optically complex water column of eastern Lake Constance in May 2012. In-situ measured and modelled remote-sensing reflectance R-rs(lambda) were matched via a parameter search procedure using genetic algorithms. The optical modelling consisted of solving the azimuthally-averaged Radiative Transfer Equation, forced with in-situ suspended matter concentration (sm) data. b(sm)*(lambda) was univocally determined at red wavelengths. In contrast, we encountered unresolved spectral ambiguity at blue wavelengths due to the absence of organic absorption in our dataset. Despite this, a surprisingly good sm retrieval regression is achieved (R-2 > 0.95 with respect to independent data) using our b(sm)*(lambda). Acquisition of accurate inherent optical properties in future field campaigns is needed to verify the estimated b(sm)*(lambda) and related assumptions.