The TriOS processor to correct above water measurements for the sky-dome reflection
Zagolski, F.; Santer, R. (2012). The TriOS processor to correct above water measurements for the sky-dome reflection. Association pour le Développement de la Recherche et de l'Innovation dans le Nord-Pas de Calais (ADRINORD): Lille. 29 pp.
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Document type: Project report
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Authors | | Top |
- Zagolski, F.
- Santer, R., more
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Abstract |
An alternative correction of the sky dome reflection is proposed to remove the reflection of the sea surface in the above water radiance measurements with the hyperspectral TriOS (Tri-Optical Sensors) instrument that were spectrally convoluted with the 13 MERIS filters (the 2 strong gaseous aborption bands being discarded from the MERIS bandset) upstream. This corrective method accounts for the polarized nature of the incident atmospheric light and of the Fresnel reflection of a wind-roughened sea surface. In order to perform this correction with in-situ measurements collected in the Northern sea (i.e., over the British Channel) on an operational basis, the TriOS processor has been developed to use as inputs the original file of radiometric measurements provided by the MUMM (Management Unit of the North Sea Mathematical Models, Brussels - Belgium) institute and the associated aerosol parameters extracted from the MERIS Ocean Aerosol product defined at the reduced resolution and available in MERMAID (MERis MAtchup In-situ Database). From the SEAPOL database, the MERIS look-up tables (LUTs) of upward/downward radiances pre-computed at bottom of the atmosphere (BOA) have been extracted for the TriOS view geometry. From these BOA radiance LUTs, a new Fresnel reflection coefficient is then deduced using as inputs the wind-speed value from the MERIS auxiliary data file and the atmospheric model observed with MERIS. |
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