93. Explaining Sentinel Satellites


Now that information about our planet is more accessible than ever before, it’s important that technical and non-technical folk learn how to engage with each other. The Copernicus Programme serves as a good example. The professionals who have put these Sentinels satellites into space are now faced with a whole new challenge.

This week’s post demonstrates how today you no longer need to be a rocket scientist to explain Earth Observation satellites to your clients or colleagues. Today, all you need is the following:

  • 2 x large cardboard boxes
  • bamboo sticks
  • a scissors



As a brief recap to a recent post about the EU and ESA's Copernicus Project, Sentinels are Earth Observation satellites which are capturing imagery of the world that is now being made freely available to the public. Although each of the satellites share the 'Sentinel' name, they are actually quite different from each other in terms of their onboard technology, their level of activity, and their distinct functions.

Here's how to explain Sentinels.




93 GEOBREADBOX - Sentinel 1.jpg

First launched in 2014, Sentinel 1A and 1B are all-weather, day-and-night radar imaging mission satellites for land and ocean services. These polar orbiting satellites provide invaluable information about sea ice, land surface motion risks and disaster response issues.

Note: Sentinel 1 is designed in the shape of a bird - and like a bird it spends its time gliding around in orbit watching out for any movement below.




    93 GEOBREADBOX - Sentinel 2.jpg

    Launched in 2015 and 2017 respectively, S-2A and S-2B are also polar-orbiting satellites. They use multispectral high-resolution imaging technology in order to monitor the land below including land-use changes, vegetation, soil and water cover, inland waterways and coastal areas.

    Note: S-2 satellites only have one 'wing' which means that they are less 'bird-like' than S1 satellites and therefore more suited to monitoring land.



    93 GEOBREADBOX - Sentinel 3.jpg

    Sentinel-3 is a sophisticated satellite which measures sea-surface topography, sea- and land-surface temperature, as well as ocean and land colour. The mission will support ocean forecasting systems, as well as environmental and climate monitoring.

    Note: Just like the S-2, Sentinel 3 only has one wing. However, the key difference is that S-3 includes a 'snorkle'-like feature in its design which indicates its relevance to the marine ecosystem.



    93 GEOBREADBOX - Sentinel 4.jpg

    Sentinel-4 is a soon-to-be launched satellite which will use Ultraviolet/visible/near-infrared spectrometer payload in order to ensure round the clock atmospheric monitoring.

    Note: Sentinel 4 has two wings (useful when in space) and an elegantly designed headpiece.




    The Sentinel-5 Precursor will provide timely data on air quality and climate (including trace gases and aerosols). It was developed in order to reduce data gaps while ESA and EUMETSAT transitions between earlier an Earth Observation system and Sentinel 5.

    Note: Since Sentinel 5 is focused on monitoring all of the nasty gases and aerosols which exist in the atmosphere, this satellite has presumably been designed to symbolise 'freshness' - like an electric fan...or a flower.



    93 GEOBREADBOX - Sentinel 5.jpg

    Sentinel-5 is a payload satellite which will, by the end of the decade, monitor the atmosphere (including air pollution, stratospheric ozone, solar radiation and climate) from polar orbit.

    Note: Sentinel 5 is a satellite which really pushes boundaries in terms of its design. And who said space was for the less stylish among us!



    93 GEOBREADBOX - Sentinel 6.jpg

    When operational Sentinel-6 will carry a radar altimeter which will measure global sea-surface height for oceanography and climate studies.

    Note: Since Sentinel-6 is designed to monitor sea level rise, it is probably no coincidence that the satellite has been designed to resemble a short but wide boat. This might be handy if the S-6 ever decides to return to its much-submerged home-planet in the future!