Dedicated measurement campaigns aimed at the validation of TROPOMI data products provide the opportunity for important checks on the data quality. Campaign-based activities are being coordinated by ESA and carried out by the members of the Sentinel-5 Precursor Validation Team (S5PVT). These efforts around the world will be used to validate the full range of TROPOMI data products. Further details are provided in this section for recent and future measurement campaigns. Click here for an overview of TROPOMI-relevant campaign efforts.