The European Union's Copernicus Sentinel-2 satellites are supplying unprecedented views of Earth, mainly providing information for agricultural and forestry practices and helping to manage food security. But how are they making a difference to farmers in particular?
Jointly operated by Airbus Defence and Space and their agronomic partners, Arvalis and Terres Inovia (the French crop technical institutes, respectively in charge of cereals and oilseed crops), FARMSTAR is a precision agriculture service that provides farmers in France with recommendation maps for various crop inputs (fertilizers, growth regulator, etc.) from satellite images.
In May 2018, it concluded its winter crops campaign, serving 16,000 farmers for a total of 93,000 field plots, amounting to 0.8 Mha. For the second year, it has made an extensive usage of Copernicus Sentinel-2 images, in particular since the mission reached its nominal 5-days revisit performance, with the second satellite also in operation.
Launched on 23 June 2015 and 07 March 2017 respectively, Sentinel-2A and -2B carry an innovative wide swath high-resolution multispectral imager with 13 spectral bands, for a new perspective of our land and vegetation.
With its multispectral imager and a swath width of 290 km, the Sentinel-2 mission not only offers continuity, but also expands on the French Spot and US Landsat missions.
Hervé Poilvé, chief scientist at Airbus Defence and Space, explains, "FARMSTAR started in 2002. For years, it used SPOT and DMC-2/DEIMOS images that we needed to complement with airborne acquisitions at critical periods in order to provide chlorophyll information, which is key to some of our nitrogen recommendation products.
"Sentinel-2 with its large and systematic imaging capacity and the spectral richness of the images brings a new era—meaning increased precision for products and higher reliability to the service."
FARMSTAR operation coordinator for image procurement, Emeline Rousseau, said, "The service covers all major cropping regions of the country. This year, we selected and processed 185 DMC-2/DEIMOS images, 150 SPOT 6/7 images and 448 Sentinel-2 images—this is a huge step from the 118 Sentinel-2 images we used the year before!"
Emmanuelle Paganelli, FARMSTAR project manager, stated, "Satellite images are processed down to individual field plots, to generate vegetation maps such as Leaf Area Index or Chlorophyll. This information is converted to agronomic indicators and then to the final nitrogen application map, based on decision rules and recommended practices that are developed by our agronomic partners.
"Information from the Sentinel-2 images really sets the reference for us now. Images are made available by the Copernicus ground segment within one day after acquisition, this is extremely important to us, as farmers are quite anxious to go in the fields and make the application as soon as weather permits."
"Thanks to frequent satellite observations, we can now achieve a steady monitoring of some major parameters of crops. This offers new perspectives of continuous assimilation within our crop growth models, and will allow building a crop advice that is even more accurate", added Baptiste Soenen, chief agronomist at Arvalis.
About the Sentinels
The Sentinels are a fleet of dedicated EU-owned satellites, designed to deliver the wealth of data and imagery that are central to Europe's Copernicus environmental programme.
In partnership with EU Member States, the European Commission leads and coordinates this programme, to improve the management of the environment, safeguarding lives every day. ESA is in charge of the space component, responsible for developing the family of Copernicus Sentinel satellites and ensuring the flow of data for the Copernicus services, while the operations of the Sentinels have been entrusted to ESA and EUMETSAT.