15:15–15:30 | ABSTRACT 1311
AQUA3C-S: A SPECTRALLY RESOLVED THREE-COMPONENT GLINT CORRECTION MODEL FOR IN SITU ABOVE-WATER RADIOMETRY FOR DIVERSE SUN-SENSOR GEOMETRIES
Accurate Remote-sensing reflectance (Rrs [sr–1]) retrieval is crucial for ecological monitoring of sea and inland aquatic systems from in situ above-water radiometry (AWR). Often, the water-leaving AWR is contaminated with reflection of diffused and direct skylights, necessitating a “glint” correction prior to accurate retrieval. The state-of-the-art glint correction approaches face challenges to provide a reliable estimate of surface glint under extreme sun zenith and relative azimuth angles, varying aerosol loads, or rough sea conditions accompanied by broken clouds. To bridge this gap, we developed AQUA3C-S, a hybrid framework that blends physics-based vector radiative transfer (VRT) with stochastic optimization to separate the true water-leaving signal from spectrally resolved surface reflection under varying sky conditions. The algorithm partitions the total glint using a spectrally solved correction factor to handle diffused skylight, accounting for both polarization and aerosol effects, while integrating an analytical model for direct sunlight reflection. Additionally, AQUA3C-S includes a spectrally dependent residual term specifically designed to capture perturbations from broken or scattered clouds. Validation across global and regional datasets (GLORIA, HYPERNET, FERRYBOX) shows the model’s robustness across diverse water types and solar zenith angles (7° to 78°), multiple sensor viewing angles (0° / 40°) and variable relative azimuths (25° to 160°). Validation of Rrs shows a near-zero mean bias (-0.000054 sr–1) for the Rrs and high spectral agreement (R² > 0.98) compared to RT simulations. Overall, AQUA3C-S can offer a reliable, autonomous solution for high-quality Rrs generation and robust aquatic ecosystem monitoring.
Soham Mukherjee, Magellium Artal Group, [email protected], https://orcid.org/0000-0001-9771-0778
Tristan Harmel, Magellium Artal Group, [email protected]
Zoé Besnard, Magellium Artal Group, [email protected]
Sabine Marty, NIVA, [email protected]
