15:00–15:15 | ABSTRACT 1281
VERY-HIGH-RESOLUTION MULTISPECTRAL POLARIMETRY FOR COASTAL MONITORING AND WATER-QUALITY RETRIEVAL
Coastal, estuarine, and inland water quality is a growing environmental and societal concern, affecting ecosystem health, human uses, and water-resource management. Ocean-color satellites provide repeated observations of optically active water constituents. However, current systems still face trade-offs: ocean-color sensors provide suitable radiometric and spectral performance but often lack the spatial resolution needed for nearshore and inland waters, while high-resolution land imagers lack optimized spectral sampling and accurate atmospheric-correction capability. This work presents POLMIS-HR, a high-resolution multispectral polarimetric imager concept planned for flight in 2028 and designed to fill this gap for coastal and inland water-quality retrieval. The design builds on the flight-proven iSIM-90 architecture and heritage from GARAI-A, a high-resolution polarimetric demonstrator already in orbit. It uses two channels: a multispectral visible channel for water-quality retrieval and a polarimetric channel for aerosol characterization and atmospheric correction. A data-driven band-selection methodology was developed using 988 OSOAA simulations representative of optically complex waters with varying CDOM, phytoplankton, detritus, and sediments concentrations. Principal component analysis and correlation-based de-redundancy identified four informative water-quality bands centered at 412.5, 442.5, 510, and 560 nm, complemented by the 490 and 670 nm polarimetric bands. Radiometric analysis demonstrates that 20 nm bandwidths, detector binning by 2, and a back-scanning factor of at least 5 can achieve SNR values above 300 while maintaining approximately 7 m spatial resolution. For aerosol characterization, the polarimetric-channel bands at 490, 670, and 865 nm were assessed through GRASP-based synthetic retrievals over 2700 aerosol scenarios, showing strong aerosol optical depth retrieval performance.
Wafaa Bousaid, Satlantis France, [email protected]
Julien Chouillou, satlantis France, [email protected]
Lucas Dubois, satlantis france, [email protected]
Daniel Luque, satlantis microsats SA, [email protected]
Oussama Rchaki, Satlantis France SAS, [email protected]
