Sea-surface reflectance factor: replicability of computed values

The sea-surface reflectance factor required for the determination of the water- leaving radiance from above-water radiometric measurements is derived from radiative transfer simulations relying on models of the sky-radiance distribution and sea-surface statistics. This work primarily investigates the impact on of various sky-radiance and sea-surface models. A specific replicability analysis is executed with the Monte Carlo code for Ocean Color Simulations (so-called MOX) accounting for the measurement geometry recommended in protocols for the validation of satellite ocean color data and commonly applied for operational measurements. Results indicate a variability of values generally lower than 2% for wind speeds up to 4 ms-1 and sun zenith angles larger than 20°. Increased variability is observed at higher wind speeds, especially for sun elevations close to the zenith or approaching the horizon. Finally, the benchmark of the ρ values from this study with those formally determined with the Hydrolight code and widely utilized by the ocean color community, exhibits systematic differences. The source of these differences is discussed and the implications for field measurements are addressed.

D'ALIMONTE Davide;  KAJIYAMA Tamito;  ZIBORDI Giuseppe;  BULGARELLI Barbara; 

2021-07-26

OPTICAL SOC AMER

JRC124665

1094-4087 (online),   

https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-29-16-25217&id=453645,    https://publications.jrc.ec.europa.eu/repository/handle/JRC124665,   

10.1364/OE.424768 (online),