He was co-science leader of the ESA Aerosol-cci projects and coordinated or participated in 18 other ESA projects leading to the strong improvement of the retrieval results of European satellites. He also participated in 31 EU projects (4 as coordinator) where satellite data are applied in air quality and climate studies. He participated in the constituting meeting of the International Satellite Aerosol Science network AEROSAT and is a member of the steering committee. He is a (co-) author of more than 210 peer-reviewed research articles (H-index 43 Web of Science; 57 Google Scholar), and co-authored 1 book on aerosol remote sensing and is editor in chief of the Section Atmosphere of Remote Sensing.