ESA mission highlighted at remote sensing conference

The International Geoscience and Remote Sensing Symposium (IGARSS) is a major annual event sponsored by the Geoscience and Remote Sensing Society to bring scientists, engineers and community leaders from all over the world to discuss the latest research findings and up-to-date technology for better understanding Earth.

IGARSS 2007 General Chairman, Prof. Ignasi Corbella, said: “Information gathered by all sensors and techniques must be wisely used mainly to understand our Earth. This will improve prediction of natural disasters or global climate change and provide tools to mitigate their consequences.

“As experts on the leading-edge technologies of Earth Observation (EO), we should play a prominent role in achieving these goals. This is our contribution to the important task of assuring people of all around the world access to resources for their subsistence without endangering the fragile equilibrium of our planet.”

With their unique view from space, satellites provide objective coverage across both space and time enabling a better understanding and improved management of the Earth and its environment. ESA’s EO satellites have given Europe a leading role in understanding the Earth’s climate, weather and environment.

Scheduled for launch in late 2008, the Soil Moisture and Ocean Salinity (SMOS) mission – the second Earth Explorer mission to be developed as part of ESA's Living Planet Programme – will contribute to furthering our knowledge of the Earth's water cycle and lead to better weather and extreme-event forecasting.

SMOS was the subject of a full day session on Thursday, with presentations covering instruments technology, calibration techniques and retrieval algorithms. SMOS will demonstrate a new measuring technique by adopting a completely different approach in the field of observing the Earth from space. A novel instrument has been developed that is capable of deriving both soil moisture and ocean salinity by capturing images of emitted microwave radiation around the frequency of 1.4 GHz (L-band). SMOS will carry the first-ever, polar-orbiting, space-borne, 2-D interferometric radiometer.

“It has been a big challenge to get this technology working but from the tests done so far on the ground, it appears we have got it right,” ESA’s SMOS Project Manager Achim Hahne said. “Of course the real proof will come once we have launched the satellite and started analysing the measurements.”

Although soil only holds a small percentage of the total global water budget, soil moisture plays an important role in the global water cycle as it controls vegetation growth to a large extent. Because in-situ measurements of soil moisture are sparse, more data are urgently required if we are to better our understanding of the water cycle so that the forecasting of climate, weather and extreme-events can be improved.

The same is true for data on ocean salinity. There are few historical measurement data, and only a small fraction of the ocean is currently sampled on a regular basis. Salinity and temperature determine the density of seawater, and in turn, density is an important factor driving the currents in our oceans. Ocean circulation plays a crucial role in moderating the climate by, for example, transporting heat from the Equator to the poles. Ocean salinity is therefore one of the key variables for monitoring and modelling ocean circulation.

The next IGARSS symposium will take place in Boston, Massachusetts, from 7 to 11 July 2008.