POLREF: A NEW SIMULATOR FOR POLARIZED REFLECTION COEFFICIENT OVER OCEAN

摘要

In the validation of the algorithm for the MERISrn(MEdium Resolution Imaging Spectrometer) atmosphericrncorrections over ocean, the water reflectancernderived from in-situ measurements represents a keyrnelement. The water-leaving radiance needs to be correctedrnfor the sky dome reflection. In the standardrnprotocol, this correction is achieved with an approximaternvalue of the Fresnel reflection coefficient of searnsurface applied to the measurement of the sky radiance.rnThis standard correction ignores the polarized nature ofrnboth the atmospheric scattering and the Fresnelrnreflection of the water surface. The introduction of thernpolarization requires a vector radiative transfer codern(RTC) in the coupled ?Ocean-Atmosphere? system.rnThe successive orders (SO) of the scattering code, offers a good opportunity to analyze thernreflected sky dome over ocean when the incident anglerncorresponds to a significant polarization by reflection.rnThe main objective here is to describe a simulator ofrnthe polarized reflection coefficient of sea surface forrnMERIS. In other words, this simulator is perfectly inlinernwith the MERIS intrument facilities processorrn(IPF) for the level-2 processing, i.e., using as inputsrnthe same spectral bandset (or nominal wavelengths),rnthe same set of illumination and viewing geometries,rnthe same set of aerosols (models and aerosol opticalrnproperties) and the same boundary conditions.