Estimativa da concentração de sedimentos suspensos com sensores ópticos: revisão

In recent decades, the use of optical sensors as an indirect way of determining the concentration of suspended sediment (SSC) has gained prominence in the monitoring programs of suspended sediment transport in rivers. However, the transformation of values recorded by sensor into CSS values is not simple and the uncertainty associated with this method is still quite high. The construction of a precise relationship between these variables is strongly linked to an appropriate calibration, and the response of the sensors is influenced by: a) characteristics of the transported sediment particle; b) geometric and optical characteristics of the instrument; c) the presence of certain components in the water column; d) some flow properties. Understanding the influence of such factors is critical in the calibration process of optical sensors and summarizes the purpose of the present article: to present the factors influencing the estimation of CSS values based on the use of optical sensors. Also represented were the results of studies where the influence of these factors was analyzed and the parameters of greater interference, which need to be considered at the time of calibration of optical sensors. We discuss further results of studies conducted in Brazil using this technology, as well as key problems and future prospects of the implementation of these instruments; also as a comparison of the data periods used for the construction of calibration equations, in Brazil and elsewhere. The characterization of the most significant factors allows effective sensor calibration and the representativeness of the data collected