Pieter De Vis (PhD), is a senior scientist in the Climate and Earth Observation group at NPL. He leads the development of tools for uncertainty propagation, atmospheric corrections and the application of Vicarious Calibration. Pieter is the NPL technical lead on the LIME, CHIME L2, FLEX DISC and VICALOPS projects and works on various projects assessing and propagating uncertainties in vicarious calibration, surface reflectance & BRDF products, ocean colour and greenhouse gasses. Within DTE-S2GOS he is the WP leader on the validation and error analysis.