Measuring Complex for Assessment of Spectral Underwater Illumination at Different Depths of Water Reservoirs

The paper studies the factors of light attenuation affecting the hydro-optical condition of a water reservoir. The proposed measuring complex for effective monitoring of spectral underwater illumination consists of two sealed submersible measuring boxes and one non-submersible device located on the water surface. Operating principles and a method for measuring spectral underwater illumination are described, along with the developed mathematical model for calculation of the sunlight intensity attenuation underwater. The measurement results of spectral underwater illumination at various depths of several sections of the Teletskoye Lake water area in the summer of 2023 are presented. The measuring complex uses interference light filters with transmission maxima in different parts of the visible spectrum at wavelengths of 433, 445, 655, 670, and 780 nm as light selective elements. The influence of a water surface weak disturbance on spectral underwater illumination measurements is analyzed and evaluated.