Validation of Aerosol Products from Polarimetric Sensors – Application to PARASOL and 3MI

With the launch of EPS-SG in 2025, a new era for a long-term operational Near-Real-Time provision of aerosol product is starting. If most of the potential for such a new remote sensing polarimetry has been demonstrated since 1996 with the 3 POLDER and PARASOL missions, the recent advance in term of retrieval but also analysis and exploitation of the data reveal more and more the potential. Indeed, polarimeters allow the observation of aerosols with a significantly improved information content which will feed the retrieval. On top of the aerosol optical thickness classically retrieved, an additional set of parameters characterizing the aerosol properties can now be derived. This specificity of polarimeters requires a more demanding effort in term of validation. We will overview the different aspects to be considered for the validation, describe the methodology for most of the parameters, and focus on some examples.