IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
mproving the Atmospheric Correction of OLCI overTurbid Waters by Using the SWIR band at 1016 nmand a new Baseline Residual Technique
Autor/es:
GOSSN, JUAN IGNACIO; DELGADO, ANA LAURA; RUDDICK, KEVIN; DOGLIOTTI, ANA I.
Lugar:
Dubrovnik
Reunión:
Conferencia; Ocean Optics Conference XXIV; 2018
Institución organizadora:
The Oceanography Society
Resumen:
Since April 2016, the OLCI era has begun, providing a new opportunity for atmospheric correction of turbid waters due to its novel spectral band in the SWIR. This new band at 1016 nm, which is much less expensive for the mission than longer SWIR bands (such as MODIS? 1240, 1640 and 2130 nm bands) may give similar and even better performances than far-SWIR and NIR bands for turbid water atmospheric correction with suitable algorithm development. Although water absorption at this band is 6.9 and 11.8 times higher than at 865 and 779 nm NIR bands, it is still not enough to fully absorb the backscattered signal produced by suspended sediments in very turbid waters such as Río de la Plata (Argentina). This means that an alternative to the ?black water? approach is needed for this sensor in this region which makes special use of the new SWIR band. In this work, we present an atmospheric correction for turbid waters developed for OLCI, based on Baseline Residuals (BLRs), i.e. spectral quantities computed from band triplets (in the same way as the Fluorescence Line Height algorithm) of Rayleigh-corrected reflectances in the Red/NIR/SWIR bands. The BLR algorithm is evaluated and compared to results obtained with standard atmospheric correction approaches, showing better general performance and spatial de-correlation between atmospheric and water signal. Although the algorithm has proven to yield satisfactory match ups of Total Suspended Matter (Delgado et al. [Ocean Optics XXIV, (2018)]), future efforts will be put in validating water reflectance using radiometric field measurements.