Professor Nigel Fox is chief scientist in Earth Observation. Climate and Optical Radiometry at NPL and visiting professor in department of meteorology, University of Reading. Nigel joined NPL from University College London in 1981 with a BSc in Astronomy and Physics. He has since been responsible for the establishment and dissemination of primary optical radiation measurement scales. Over the last three decades Nigel has focused on EO satellite observations, pre-flight and post-launch cal/val culminating in as lead scientist of the ESA TRUTHS satellite mission. Nigel represents the UK in CEOS WGCV and is chair of the IVOS sub-group.