ERS stands for European Remote Sensing satellites. Between them, ERS-1 and ERS-2 have been watching over the Earth for more than 16 years. The European Space Agency

(ESA) mission has proved incredibly successful and is still producing useful results.

The satellites have provided scientists with vital information about Earth's land, oceans and polar caps. The two satellites have monitored our planet’s changing climate and measured the rise in sea levels. They have tracked pollution and assessed the hole in the ozone layer.

As well as gathering information on the Earth’s environment, the ERS satellites have been used to monitor natural disasters. Following the eruption of Mount Etna in 2001, for example, images from the satellites were used to help ensure the safety of people living in nearby villages.

The ERS programme laid the foundations for the Envisat mission. Instruments on Envisat are an advance on those flown on ERS. With Envisat due to remain operational until at least 2010, scientists will eventually have almost 20 years of continuous data. Already there is sufficient satellite information to show long-term trends in sea level rise and reduced ice cover in the Arctic.

Mission facts

• ERS-1 was the first satellite launched by ESA to monitor Earth from space. It was taken out of action in 2000 after nine years of service.
  
  
• Launched in 1995, ERS-2 has now been in orbit for more than 12 years. ERS-2 continues to provide information about our planet's behaviour and how it's changing.
  
  
• The two satellites operated in tandem for nine months during 1995-96 to provide scientists with an accurate 3-D digital map of Earth.

Technology

Both satellites carry the same basic set of radars and infrared sensors. ERS-2 is also fitted with an ultraviolet spectrometer that allows it to monitor the ozone layer.

As ERS-2 was based largely on existing technology, it cost 60% less to develop and launch than ERS-1. ERS-2 has already been in service for longer than its predecessor, and should continue to work for a number of years to come.

For more information on ERS see the ERS webpages.

UK involvement

The ATSR (Along Track Scanning Radiometer) instruments on ERS, which provide images of the Earth's surface from space, were designed and developed by a consortium of research institutes. They were led and supported by BNSC partners STFC Rutherford Appleton Laboratory and Natural Environment Research Council (NERC).

Science teams across the UK continue to rely on information obtained by the ERS mission. Much of this work is carried out by the Data Assimilation Research Centre at the University of Reading (DARC).