Window on the World
Everyday the fine balance of our planet’s natural ecological system is gradually being altered by many of the normal activities associated with modern daily life that we all take for granted.
Today, therefore, we have an urgent need to monitor and understand both man-made and natural changes to our atmosphere, land and the oceans in every part of the world.
In many cases satellites are the only way to obtain suitable data. Satellites orbiting the Earth can gather comprehensive information. But visual systems that rely on daylight and clear conditions to ‘see’ the surface have a distinct disadvantage – they cease to function when it is cloudy or at night.
So European engineers, under the direction of ESA, developed a special instrument called a Synthetic Aperture Radar (SAR). As one of the key instruments on the ERS-1 & 2 satellites the SAR is a high-resolution, wide-swath imaging radar producing high quality colour images of the oceans, coastal zones, polar ice and land regions irrespective of weather conditions, cloud coverage or night/daytime.
It works by bouncing microwaves off the Earth’s surface and measuring the reflected radiation. SAR also has five different modes of operation, allowing a variety of image types and giving us a new and permanently open window on the world.
What is ERS?
The first SAR was launched into space by Europe’s Ariane-4 rocket in July 1991 as one of three main instruments on ESA’s ERS-1 spacecraft. It was followed by a second on ERS-2 in 1995.
At the time the two ERS satellites were the most sophisticated Earth observation spacecraft ever developed and launched in Europe.
ERS-1 completed its operation in 1999, overlapping with the new ERS-2, which was launched in 1995. These highly successful ESA satellites have collected a wealth of valuable data on the Earth’s land surfaces, oceans, and polar caps.
They have been called upon to monitor natural disasters like severe flooding or earthquakes in remote parts of the world.
On a global scale they have expanded our understanding of the interaction between the oceans and atmosphere, ocean currents and changes in the Arctic and Antarctic ice, giving climatologists more confidence in assessing climate trends.
The ERS satellites have also kept a close eye on agricultural areas, forests, coastlines and marine pollution.
By detecting land-use changes, such as the destruction of tropical rain forests, ERS data has helped governments around the world 'police' a broad range of local and global environmental problems.
For the good of Europe
As the most comprehensive modern day source of satellite environmental data, the ERS spacecraft have brought significant benefits to Europe and the rest of the world.
These benefits have ranged from improved public services, such as weather forecasting and crop monitoring, to the creation and sharing of commercial and industrial enterprise, and helping European scientists to excel in key areas of environmental research.
Who uses the data?
Today, several hundred research groups world-wide, involving at least 2,000 scientists, use ERS data to further their studies.
Much of this research has paved the way for the formation of a number of international initiatives, with countries across the globe working together to combat environmental problems.
Perhaps the most significant of these is the Inter-Governmental Panel on Climate Change (IPCC), which has led to the Montreal Protocol for world-wide reduction in the production of aerosol gases/ChloroFluoroCarbons (CFCs).
Last update: 24 August 2004