Using Sentinel 2 optical satellite data from April to October 2022 as the data source

Use Sentinel 2 A/B MSI with good radiation performance. Obtained L1C data from ESA's Copernicus Data Open Center. Atmospheric correction is carried out using the SEN2COR algorithm provided by ESA. However, SEN2COR is a terrestrial atmosphere correction algorithm that needs to be targeted to further remove the effects of sky light, solar flares and residual aerosol scattering. A sampling random forest regression (RFR) method was used to build a water quality parameter model. By adjusting the optimal input variables of the input algorithm, the optimal hyperparameters of each algorithm are obtained through the grid search method.

A large number of field surveys and satellite-earth synchronous data were used to conduct model research. The results showed that the RFR chlorophyll a concentration algorithm had high accuracy, with an uncertainty of 21.92%, a deviation of 4.29%, a slope of 0.64, and a root-mean-square logarithmic error of 0.235.