| Total suspended solids(TSS) concentration is one of the most important indexes for inland water quality assessment and water environment evaluation. Compare to conventional measurements, remote sensing in estimating water indexes has excellencies of high efficiency, large area, effects, and it can get the continuous data. Currently there are many models of estimating the total suspended solids based on satellite data.However, due to water quality parameters with the natural environment, changing all the time. Actual sampling always need a long time, but Satellite data acquisition is a moment. During building retrieval model, the satellite data and water quality data are non-synchronization. This paper attempts to improve this problem.Taihu lake was selected as study area. First, we use the measured spectral synchronization data (ASD spectrometer data) to simulate HJ-1 multiply Spectral channels. Next, Build retrieval model of total suspended solids concentration based on measured data. Then through the scaler of measured spectral data (ASD spectrometer data) and HJ-1 satellite, we will get the relations of the modified parameters. At last, This paper is to build total suspended solids concentration retrieval model of Taihu lake which is based on HJ-1 satellite. Satellite data comes from HJ-1BCCD2 satellite.Through the research we get the following conclusions:(1) Water optical properties of Taihu lake and the suitable band for retrieval of total suspended solids concentration.Taihu lake has typical inland II water's optical properties. By water absorption and scattering properties of each component analysis and combined with the samples' measured spectrum, we get the total suspended solids concentration's appropriate estimated band is in the 600 nm-700nm.(2) Build the total suspended solids concentration estimation model based on ASD spectrometer data.ASD measured by spectral simulation HJ-1 satellite, four channels (HJ1, HJ2, HJ3, HJ4), by spectral simulation ASD band (ASD1, ASD2, ASD3 and ASD4).By analyzing the correlation between total suspended solids concentration and band combinations we get ASD3, ASD4, ASD3* ASD4/ASD1, ASD3* ASD4/(ASD1 +ASD2). Using these four factors as independent variables to build models of linear, logarithmic, polynomial, power and other forms. Through a series of comparative analysis, the final choice is zhe linear model:SS=2004* ASD3-34.95.(3) Correction between ASD spectrometer and HJ-1B CCD2.Total suspended solids concentration estimation mode based on HJ-1 multi-spectral data. By scaling we get the total suspended solids concentration's parameter relationship between ASD spectrometer and HJ-1B CCD2:ASD3= 0.284* HJ3-0.014. Finally the total suspended solids concentration's estimation model which based on HJ-1B CCD2:SS= 569.5* HJ3-63.9.Except a few abnormal samples, the model's average relative error is 0.25 and compared to traditional methods, this model improved in accuracy.(4) Temporal and Spatial Variations of total suspended solids concentration in Taihu lake.Firstly in the time scale, total suspended solids concentration of Taihu lake has higher levels at autumn and winter.Order:winter> autumn> spring, summer. especially in January and December, total suspended solids concentration is highest. At spatial distribution, mostly, southwest region higher than the northeast region, relatively central region is higher. In Xintang Hong Kong, Mei mouth, new port Meiliang Lake area will be relatively high. East Taihu lake has low value. In general, total suspended solids concentration'laws in Taihu lake is not obvious compare to the other water quality parameters. |
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