The Copernicus programme of the European Union operates the Sentinel satellite family — a fleet of free, open, operationally guaranteed Earth-observation missions. Sentinel-1 provides all-weather radar imaging; Sentinel-2 delivers 10 m multispectral optical coverage every few days; further Sentinels measure oceans and atmosphere. Copernicus turned Earth observation from a data-scarcity problem into a data-exploitation problem.
Sentinel-2: the optical workhorse
Sentinel-2 carries a 13-band multispectral imager at 10, 20 and 60 m resolution, with a wide 290 km swath and roughly five-day revisit from the constellation. Its four red-edge and NIR bands were designed with vegetation in mind, making it the default sensor of modern agricultural monitoring and land-cover mapping.
Data arrives processed to surface reflectance with scene classification masks — effectively analysis-ready — and free at continental scale, which is why it anchors countless operational services.
Sentinel-1: radar on a schedule
Sentinel-1’s C-band synthetic aperture radar images regardless of cloud or darkness on a systematic plan, giving guaranteed observations where optical sensors deliver luck. Flood mapping during storms, ship monitoring, and continent-wide interferometry for ground deformation all run on its dependable cadence.
Its archive of coherent acquisitions is the raw material for InSAR subsidence services — a decade of millimetre-scale ground-motion history over most of the planet.
Why “operational” matters
Copernicus commits to continuity: successor satellites are funded and launched so services can be built on decades-long expectations, not single research missions. That guarantee — plus genuinely open licensing — is what let public agencies and companies wire Sentinel data into production systems.
The practical consequence for users: baseline monitoring at zero data cost, with commercial imagery reserved for the tasks that truly need higher resolution or tasking.