First Results of the COLOR (CDOM-Proxy Retrieval from aeOLus ObseRvations) Project

During the last decade, new applications exploiting data from satellite-borne lidar measurements demonstrated that these sensors can give valuable information about ocean optical properties. Within this framework, COLOR (CDOM-proxy retrieval from aeOLus ObseRvations) is an ongoing (KO: 10/3/2021) 18-month feasibility study approved by ESA within the Aeolus+ Innovation program. COLOR objective is to evaluate and document the feasibility of deriving an in-water AEOLUS prototype product from the analysis of the ocean subsurface backscattered component of the 355 nm signal. In particular, COLOR project focuses on the AEOLUS potential retrieval of (1) diffuse attenuation coefficient for downwelling irradiance (Kd [m−1]) and (2) subsurface hemispheric particulate backscatter coefficient (bbp [m−1]). The core activity of the project is the characterization of the signal from the AEOLUS ground bin. In principle, the ground bin backscattered radiation signal is generated by the interaction of the emitted laser pulse radiation with two media (atmosphere and ocean) and their interface. To characterize this ground bin, two parallel and strongly interacting activities were developed: (a) radiative transfer numerical modelling and (b) AEOLUS data analysis. The preliminary results about the abovementioned activities will be here presented.