REVISITING SWIR-BASED ATMOSPHERIC CORRECTION OVER COASTAL WATERS: A RADIOMETRIC ANALYSIS

Remotely sensed measurements of the color of coastal ocean waters give insights into the status of coastal ecosystems, interactions between terrestrial and marine systems, and aid in forecasting occurrence of phenomena like harmful algal blooms. Retrieval of water quality indicators from coastal optical imagery requires the removal of atmospheric effects. The short-wave infrared (SWIR) observations can be used to estimate dominant aerosol conditions. The next-generation NASA ocean color imagers will be equipped with high-fidelity SWIR bands for the atmospheric correction. In this research, we provide a full analysis of the optimal and threshold configurations of the SWIR channels, their signal-to-noise ratio (SNR), and their sensitivity to different aerosol models/turbidities. This is performed through radiative transfer modeling and radiometric analysis together with examining moderate resolution Operational Land Imager (OLI) data products at various solar conditions. The preliminary results indicate that the SWIR bands can be placed at any position within the relevant atmospheric windows to meet the existing radiometric requirements for the upcoming ocean color missions. Overall, the findings will allow further degree of freedom at the design stage.