The European Space Agency’s Sentinel-2 programme is almost two years old, with the first satellite, Sentinel-2A, being launched on 3 June 2015 and the second, Sentinel-2B, on March 7th this year. The comparable US run Landsat program has been ongoing since 1972, with the latest satellite in the series being Landsat 8. Sentinel-2 and recent Landsat 8 imagery is available on both Amazon Web Services (AWS) and on Google Cloud.
Sentinel-2 imagery is slightly higher resolution than Landsat 8 imagery, at 10 m per pixel. Landsat 8 imagery is 30 m per pixel for colour, which can be pansharpened to 15 m per pixel.
Sentinel-2 imagery is distributed in smaller tile sizes than Landsat imagery, which we find to be generally more manageable. It does mean that we sometimes have to download multiple tiles for a given area and the colour balancing may end up being different between the tiles. One problem with Sentinel-2 imagery is the provided thumbnails are very small and it is often difficult to tell whether what you are interested in is visible in the image without downloading and processing the whole image. The Landsat imagery is provided with a much larger thumbnail.
Google has taken note of the Sentinel program and now uses Sentinel-2 imagery in conjunction with Landsat imagery when creating their yearly global mosaics.
With the launch of Sentinel-2B in March, Sentinel imagery now covers the earth roughly every 5 days. It is also made available remarkably quickly. When looking at the floods in Sri Lanka we were able to obtain imagery the day after it was captured.
To process Sentinel-2 imagery, we usually use Spectral Discovery for Sentinel-2 Imagery from GeoSage, but it is relatively easy to process it using free tools such as GIMP.
To explore sentinel imagery use our KML for animating Sentinel imagery from this post.
Flooding along the Black River, Arkansas, USA, in May.
Copernicus Sentinel data, 2017.
To see the above image in Google Earth download this KML file.
About Timothy Whitehead
Timothy has been using Google Earth since 2004 when it was still called Keyhole before it was renamed Google Earth in 2005 and has been a huge fan ever since. He is a programmer working for Red Wing Aerobatx and lives in Cape Town, South Africa.