SERCO-IDEAS-QA4EO-RM/SUB28 - IDEAS- QA4EO - Quality Assurance For Earth Observation - QA4EO/SER/SUB/28 - CCN9

Sun photometers are able to retrieve AOD only under cloudless (sun not obscured by clouds) conditions. Long term automated measurements use algorithms in order to identify and eliminate data affected by such cloud presence. Most algorithms are based on defining the limitations of short term changes of the radiative fields that can be attributed only to aerosols. We plan to try to combine instruments measuring at different frequencies and spectral resolutions in order to improve such algorithms especially in cases of clouds with low radiation related variability (e.g. cirrus) and aerosol cases with high variability (dust, smoke, pollution episodes etc), where the related uncertainties are higher. Also to use campaign based data from different instruments with different processing algorithms and measurement frequencies (e.g. CIMEL ~15min, PFR ~1 min) , in order to identify cloud elimination algorithm related advantages but also disadvantages.