Europe’s latest weather satellites

• In operation
• First launch 2002
• Due to be replaced by 2018

The MSG (Meteosat Second Generation) weather satellites are providing an unprecedented degree of accuracy. Every 15 minutes they take an image of Europe and Africa showing cloud, land, sea and snow to a resolution as small as one kilometre.

The satellites can also detect infrared wavelengths to produce an accurate picture of the temperature of clouds, land and sea surfaces at all times of the day and night. Because the images are taken so frequently, weather conditions can be monitored as they develop.

The operation of Europe’s weather satellites is co-ordinated by EUMETSAT with BNSC partner the Met Office representing the UK. EUMETSAT has a close working relationship with the European Space Agency (ESA) which has responsibility for initial satellite development on MSG.

The MSG satellites have provided experimental evidence for the greenhouse effect. The GERB instrument on board has been measuring the difference between the radiation entering and radiation leaving the atmosphere.

The first MSG satellite was launched in 2002 and, following in-orbit testing, was renamed Meteosat 8. Meteosat 9, launched in December 2005, is now the prime satellite for European weather services. Meteosat 8 has been redeployed as the back-up satellite and will operate in ‘rapid scanning’ mode to give five minute updates over a smaller area.

The replacement for the MSG satellites, Meteosat Third Generation (MTG) will be needed by 2015 and is already under development.

Mission facts

• Europe has operated a series of weather satellites for more than 30 years. The first Meteosat was launched from Cape Canaveral in November 1977. These spacecraft have transformed the accuracy of the weather forecast.
  
  
• The MSG satellites are stationed high above the Earth in geostationary orbit. This means they rotate around the Earth at the same speed as the planet spins. So effectively they remain over the same part of the globe.
  
  
• The satellites send back images and measurements of the atmosphere. This is incorporated into computer models to enable forecasters to make predictions of what the weather has in store.
  
  
• Because the images are taken so frequently, weather conditions can be monitored as they develop. This has led to the advent of what forecasters call the ‘nowcast’ allowing, for example, warnings to be given to aircraft about an approaching thunderstorm or to help government agencies prepare for heavy flooding.
  
  
• Unlike previous weather satellites, MSG can monitor ‘low-visibility’ weather such as fog or thunderstorms.

Technology

Weather satellites use a range of different cameras and detectors to view the Earth. As well as transmitting visible images, instruments can measure infrared (heat) and solar radiation.

Instruments:

SEVIRI (Spinning Enhanced Visible and Infrared Imager) is the main instrument on the MSG satellites. It scans the Earth's surface every 15 minutes to send back data concerning heat and weather patterns.

GERB (Geostationary Earth Radiation Budget) measures the amount of solar radiation arriving on Earth and the amount leaving or being scattered. GERB has provided experimental evidence for climate change. It has also helped improve climate forecasts by monitoring the greenhouse effect of small dust particles over the Western Sahara and by reassessing the brightness of clouds.

MCP (Mission Communication Payload) communicates data collected by SEVIRI and GERB back to Earth.

S&R (Search and Rescue transponder) receives distress signals from any mobile unit within the MSG coverage zone of Europe, Africa and the Atlantic Ocean.

UK involvement

The MSG project has seen involvement from more than 50 science and industry partners in the UK.

Management:

The Government contributed directly more than £6 million towards programme development.

The Met Office has put £89 million into the project, funding operating costs.

Research and Operation:

AEA Technology Space developed infrared calibration systems for both the GERB and SEVERI instruments. AEA Technology, European Space Tribology Laboratory worked in both a developmental and consultative role on the SEVERI and GERB instruments.

Astrium Limited provided the key link between MSG in space and end users: The Image Processing Facility (IMPF).

BAE Systems supplied infrared detectors under contract with Astrium Limited.

COMDEV Europe Limited produced pre-amplifiers for the SEVIRI instrument under contract to Astrium Limited. These units amplify small signals from infrared detectors for transmission to the ground.

Imperial College London calibrated the GERB instrument.

Leicester University built the detector and associated electronics for GERB.

LogicaCMG delivered a new processing system for MSG known as the Meteorological Products Extraction Facility (MPEF).

MT Satellite Products Ltd. tested and produced filters that prevented particles from reaching thrusters on MSG.

Oxford University provided flexible cabling for SEVERI.

The STFC Rutherford Appleton Laboratory has provided overall management of the GERB instrument as well as the system design, integration and testing. It also led the overall design of the ground segment.

VEGA Group plc supports all of the MSG operations team and aids with the procurement of the MSG system including the systems architects, consultants and engineers.