Consistency of above and in-water radiometric measurements in eutrophic and absorbing waters

Kurzfassung

Radiometric measurements were conducted across nine optically complex lakes representing a wide range of conditions, from Nohipalu Valgjärv (Chl a = 1.6 μg/L, aCDOM(442) = 1.5 m–1, TSM = 1 mg/L) to highly eutrophic and strongly absorbing lakes, with chlorophyll-a concentrations reaching up to 149 μg/l and aCDOM(442) up to 54 m–1.

Four sets of both above-water and in-water radiometric measurement setups were used across these lakes. The systems comprised of TRiOS RAMSES sensors, custom-built hand-held sensor systems (OOSS), and an automated measurement platform (LimnoVIS), designed to minimize disturbances from the boat and crew. The performance of the different setups, along with their associated interpolation schemes, was compared, and the consistency between above-water and in-water radiometric measurements was assessed.

Additionally, matchups with EnMAP, OLCI (Sentinel-3), and MSI (Sentinel-2) were analysed.