[SatNews] Seamless observations will be possible each hour of Europe and North Africa...

Astrium will be the European Space Agency’s (ESA) prime contractor for the development and construction of two highly accurate instruments designed to monitor the atmosphere. The two spectrometers, known as Sentinel-4, will, for the first time, gather data on the quality of the Earth’s atmosphere and its chemical composition from a geostationary orbit. Their position at an altitude of 36,000 kilometres will allow seamless observations of Europe and North Africa to be taken hourly. The data collected in this way is urgently required for climate research; for instance, it would have made it possible to determine the spread of the ash cloud that followed the eruptions of Iceland’s Eyjafjallajokull and Grimsvotn volcanoes in 2010 and 2011.

“It is only with satellites that we can observe the environment globally and continuously – and with the latest technology. Sentinel-4 will be an important MTG (Meteosat Third Generation) instrument for high-definition monitoring of the atmosphere over Europe. This demonstrates how Astrium’s high-tech expertise serves the environment as well as global security,” said Evert Dudok, CEO of Astrium Satellites. “What’s more, as prime industrial contractor, Astrium will coordinate the work of 45 companies in 11 European countries in the construction of Sentinel-4.” He added that Astrium is already building two Sentinel satellites for Europe’s major Global Monitoring for Environment and Security (GMES) program on behalf of ESA.

With this 149.2 million euros contract for Sentinel-4, Astrium will take charge of a significant element in the GMES program. The company has already gained valuable experience from developing Envisat, the first European low-Earth orbit environmental satellite, and its Sciamachy instrument, which is the predecessor to Sentinel-4. The instruments, weighing around 150 kilograms, will be launched in 2019 and 2027, respectively, on board the MTG weather satellites and will then each operate for a period of eight years. At the core of these high-tech instruments are two spectrometers that analyse by wavelength the sunlight reflected by gas molecules in the atmosphere. They are sensitive not only to visible light but also to the ultraviolet and infrared regions of the electromagnetic spectrum. The intensity of specific wavelengths is then measured by CCD (charge-coupled device) sensors similar to the ones found in digital cameras. This gives very precise information on the presence of trace gases such as ozone or nitrogen oxide. It also allows extremely precise measurement of aerosols and the extent of cloud cover. Astrium is building a team of approximately 45 subcontractors for the development and construction of Sentinel-4. Work will begin in a core team including the Munich-based company Kayser-Threde and atmosphere researchers at IUP University of Bremen.