The Sentinels are a fleet of satellites designed to deliver the wealth of data and imagery that are central to the European Commission’s Copernicus programme.


Sentinel-3 carries a series of cutting-edge instruments for systematic measurements of Earth’s oceans, land, ice and atmosphere.

Over oceans, Sentinel-3 measures the temperature, colour and height of the sea surface as well as the thickness of sea ice. These measurements will be used, for example, to monitor changes in sea level, marine pollution and biological productivity.

Over land, this innovative mission will monitor wildfires, map the way land is used, provide indices of vegetation state and measure the height of rivers and lakes, complementing the high-resolution measurements of its Sentinel-2 sister mission.

Alter Technology was in charge of the engineering, testing and procurement of the electronic components on-board the satellite. We supplied 256.000 components and performed 2.543 tests, such as precap and buy-off inspections, DPA, incoming inspections, upscreening and Radiation Verification Test among others.

SENTINEL 3A makes use of multiple sensing instruments to accomplish its objectives:

  • SLSTR (Sea and Land Surface Temperature Radiometer)
  • OLCI (Ocean and Land Colour Instrument)
  • SRAL (SAR Altimeter)
  • DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite)
  • MWR (Microwave Radiometer)

The core services of the SENTINEL 3A mission are:

  • Numerical Ocean Prediction
    Forecasting atmospheric and oceanic conditions. More accurate forecasting helps protect people from the impacts of extreme weather events such as hurricane winds, storm surges and flooding.
  • Maritime Safety and Security
    Monitoring ocean conditions for security and safety such as pollution (as a consequence of shipping accidents), passenger vessel safety and potential terrorist actions.
  • Coastal Zone Monitoring
    Observing the status and characteristics of coastal zone waters to support environmental monitoring of water quality and phenomena such as harmful algal blooms for habitat assessment and management (aquaculture, sea-defences and tourism).
  • Open Ocean and Ice Monitoring
    Monitoring the health and state of the oceans globally, on a daily basis to increase the predictability of characteristics such as sea state, ice formation, ocean circulation and the impact of physical conditions on ocean biogeochemistry.
  • Atmospheric Services
    To provide inputs such as sea surface temperature, surface wind speed or sea state to weather prediction models.
  • Global Land Monitoring Applications
    Providing information about the land surface that will allow monitoring of parameters such as regional and continental-scale land cover, vegetation state, vegetation productivity and fire (location, intensity and effect). Inland rivers and lake height levels can be monitored and digital elevation models of the Earth’s surface can be derived providing new information for hydrological services.
  • Environmental Policy and Law
    Supporting international negotiations and agreements (The United Nations Kyoto Protocol, the Framework Climate Convention, the European Water, Framework Directive [RD-130], the Biodiversity Convention, the EU Marine Strategy) and providing marine, coastal and land environmental data.
  • Climate Change Monitoring
    Providing the accurate, stable, long term and consistent quality data required to monitor and study the regulating effect that ocean processes exert on climate. Improved analysis of climatological data sets will also support and enhance operational NRT forecasting applications.
  • Support to European Security, Humanitarian and Emergency Services
    SENTINEL-3 data are not optimised for the rapid-task requirements typical of these services (e.g. floods, forest fires, earthquakes, humanitarian aid in emergencies) but they will provide a baseline wall-to-wall mapping capability at reduced resolution (0.3 – 1 km) prior to and following emergencies to support security, humanitarian and emergency services

Sentinel-3A Liftoff


Info about the LAUNCH in our Event Manager.

Media ATN
Latest posts by Media ATN (see all)