ESTIMATION OF OPTICALLY ACTIVE CONSTITUENTS OF WATER BY REMOTE ORBITAL SENSING

Abstract

The objective of this study was to evaluate the potential use of LISS-III / Resourcesat-1 images in the estimation of optically active constituents of water in the Passo Real reservoir. With the satellite images used for the analysis of the water reflectance, it was possible to extract information in pixels with spatial resolution of 23.5 meters. The selection of images was made from the availability of scenes without clouds at the closers days to the field work. The processing of the images to correct the atmospheric effects and the transformation of the digital numbers into reflectance values were performed in the software ENVI 5.0 limnological data spatialization obtained in situ were carried out by interpolation in the software Spring 4.3.3 and the spatializations of the data estimated by satellite were generated by slicing the image generated by the insertion of equations obtained in the models. From the available data set it was possible to produce models capable of estimating total suspended solids, turbidity and water transparency with only a single spectral band, band 3 (620 to 680 nm) of the LISS-III / Resourcesat-1. With the application of the spectral band ratio technique, it was possible to generate a model to estimate the chlorophyll-a concentration.