DBPapers
DOI: 10.5593/sgem2017H/33/S12.027

INCREASING THE ACCURACY OF MULTISPECTRAL TELEVISION MEASUREMENTS OF PHYTOPLANKTON PARAMETERS IN AQUEOUS MEDIA

S. Kvaternyuk, V. Pohrebennyk, R. Petruk, O. Kvaternyuk
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-27-0 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 33, 219-226 pp; DOI: 10.5593/sgem2017H/33/S12.027

ABSTRACT

Multispectral television measurements can be used for applied tasks of environmental monitoring, in particular for measuring the parameters of phytoplankton in aqueous media. In this case, the concentration of phytoplankton particles in the water volume is determined, the average particle sizes and the average concentration of chromophores in the near-surface layer.
The aim of the work is to improve the multispectral television method to increase the accuracy of measuring the parameters of phytoplankton. An improved method for multispectral television measurement of phytoplankton parameters in aqueous media, which includes sampling, determination of the qualitative and quantitative composition of suspended particles by means of a flow multispectral television measurement analysis of continuous particles, the comparison of the obtained data with the normalized values is supplemented by the fact that multispectral images are analyzed at certain wavelengths, which allow to indirectly measure the average particle size of phytoplankton in aqueous media using the regression equation, which connects the particle sizes with the results of multispectral measurements. The influence of the effect of localized absorption by chromophores in phytoplankton particles of aqueous media on the accuracy of multispectral measurements was studied. The localized absorption of radiation leads to a decrease in the total absorption index of the aquatic medium in comparison with the homogeneous distribution of chromophores. A consequence of this is an increase in the depth of penetration of light into the medium and an increase in the coefficient of diffuse reflection. Depending on the concentration of phytoplankton particles, their shape and size, such changes in penetration depth and reflection coefficient can be very significant. Therefore, without taking into account the effect of localized absorption in phytoplankton particles, the errors in measuring their parameters can reach 70-80%, which will not allow using the developed means for applied tasks of ecological monitoring. When this effect is taken into account and the corresponding correction factors are introduced, it is possible to obtain a total measurement error of no more than 0.5%.
According to the results, it can be concluded that an improved method of multispectral measurements makes it possible to increase the accuracy of measuring phytoplankton parameters by taking into account the effect of localized absorption in scattering particles.

Keywords: environmental monitoring, multispectral measurement, water, particles, light scattering.