Мультиспектральні вимірювання біомаси фітопланктону у водних середовищах для задач екологічного контролю

Abstract

The aim of the work is to increase the accuracy of indirect measurements of phytoplankton biomass in natural water bodies on the basis of the results of multispectral measurements using various options for implementing environmental monitoring tools. The inverse problem of indirect measurement of phytoplankton biomass in natural water bodies is solved based on the results of multispectral measurements. The analysis of errors in biomass measurements of phytoplankton in natural water bodies is carried out under various options for the implementation of environmental monitoring tools. When studying aquatic ecosystems, considerable attention is paid to phytoplankton, as the main producer of primary organic matter. To assess the trophic status and ecological control of the quality of the waters of natural water bodies, phytoplankton parameters such as abundance, biomass, the content of chlorophyll and other pigments in the raw mass of phytoplankton, the ratio between the main pigments that allow us to evaluate the production-degradation processes in the aquatic ecosystem are used. As a result of solving the inverse optical problem of determining phytoplankton biomass in natural water bodies on the basis of multispectral measurements, regression equations have been obtained, which allow to indirectly measure the biomass of phytoplankton when used in environmental controls. In the course of multiple regression, the number of spectral channels of the multispectral measurement instrument is obtained, as well as the methodical error, which is determined by how accurately the regression equation allows indirectly measuring the biomass of phytoplankton. Thus, when light emitting diodes and laser diodes were used in the radiation source, 7 and 8 spectral channels were obtained, respectively. When using a monochromator as a radiation source, only 3 spectral channels are obtained. The value of the methodical measurement error, which is determined by the regression equation, is obtained less than the instrumental error, which is determined by the analog-to-digital conversion and the CCD camera noise. The general error of the indirect measurement of phytoplankton biomass in natural water bodies is calculated on the basis of multispectral measurements, which was from 0.167 to 0.397% for various versions of the measuring instrument.