Sentinel-1, the first Earth observation satellite to be built for Europe’s Copernicus programme. It is a C-band imaging radar mission to provide an all-weather day-and-night supply of imagery. The mission will benefit numerous services such as those that relate to monitoring Arctic sea-ice, routine sea-ice mapping, surveillance of the marine environment, including oil-spill monitoring and ship detection for maritime security, monitoring land-surface for motion risks, mapping for forest, water and soil management, and mapping to support humanitarian aid and crisis situations.