PASSIVE OPTICAL SENSING OF RIVER PLUMES FROM BOARD OF A VESSEL USING GYRO-STABILIZED COMPLEX EMMA

Goncharenko I.V., Rostovtseva V.V.

The greatest variability of the ecological state of coastal waters is observed in the areas of river mouths. River plumes can differ from the surrounding sea water both in the composition of impurities and in their concentration. Moreover, the size and position of plumes are characterized by strong variability. Monitoring of such water areas requires measurements with high spatial and temporal resolution. The possibility of operative estimation of natural sea water components distribution at a river plume by the method of passive optical sensing from board a vessel was demonstrated at the Caucasian coast of the Black Sea. Portable three-channel hyperspectral complex EMMA (Ecological Monitoring of Marine Areas) installed on a gyro-stabilized platform was used for this purpose. The data of the EMMA complex were processed by a special algorithm, which allowed obtaining light absorption spectra of sea water and estimating concentrations of its natural components. The efficiency of the gyro-stabilized complex is discussed in comparison with measurements without stabilization. It has been shown that it is possible to obtain estimates of the concentration of the main natural seawater constituents with a gyro-stabilized complex EMMA under conditions of uneven illumination at low sun position, which significantly expands the time frame for measurements. The presented complex may be useful for ground truth measurements in coastal areas of the ocean or inland seas with river plumes.

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