2010/03/08 > eTech France 238 > CryoSat-2 The Ice Observer Soon In Orbit

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		Special Report CryoSat-2 The Ice Observer Soon In Orbit http://www.bulletins-electroniques.com/actualites/62523.htm On February 25 this year, the CryoSat-2 satellite engineered by EADS ASTRIUM will be launched by a Russian-Ukranian Dnepr rocket from the Baikonur Cosmodrome in Kazakhstan. CrysoSat will be the third of EAS's Earth Explorer satellites in orbit following GOCE and SMOS (launched in March and November 2009, respectively). CryoSat-2 will be placed into orbit 700km above Earth. For the next five years, its mission will be to study terrestrial ice and map the thickness of floating marine ice, which can be up to five kilometers in Antarctica. The mission will deliver data on the rate of change of polar ice thickness. SIRAL, the first all-weather hyper frequency radar altimeter manufactured by Thales Alenia Space, will be one of the several instruments onboard ensuring mission success. Did you know that South Pole ice accounts for about 80% of the Earth's freshwater reserves and if the 2 to 3 kilometers of ice thickness covering this area of our planet (28 times the size of France) melted, the level of the oceans would rise by about 70 meters? The North and South poles play a vital part in atmospheric circulation and climate regulation. They create a climate balance, not only by absorbing the Equator's heat but also by acting on marine currents, including the renowned Gulf Stream. Accordingly, our future looks bleak as the ice fields weaken and break up increasingly year after year. This explains why these areas must also be observed from space so their changes can be monitored. Actually, space observation has already allowed scientists to measure an 8% regression of the ice pack per decade. The ESA's CryoSat-2 satellite scheduled for liftoff next February 25 is part of the far-reaching observation mission of polar regions. After the failed CryoSat-1 launch in 2005, it was decided to design a new satellite - CryoSat-2 - carrying out the same mission. Lofted into a polar orbit at an altitude of more than 700 kilometers, the satellite will be monitoring changes in the thickness of polar ice and floating ice floes to gain a firmer grasp on the rate of reduction of polar ice thickness. To do so, the satellite is equipped with a new generation of a very high-resolution altimeter-interferometer sweeping 250-meter wide areas on the ground. The main instrument aboard CryoSat-2, called SIRAL (Synthetic Aperture Interferometer Radar Altimeter), uses interferometry to measure the topography on each side of the satellite ground track. SIRAL has a Synthetic Aperture Radar (SAR) for very accurate topography along the track. All the information will be critical for the development of the models used for climate change analysis and predictions. Aside from the SIRAL instrument, CryoSat-2 will be carrying a laser retro reflector that will be used to determine its exact position and DORIS, the CNES orbitography instrument, now fitted onto 5 operational satellites. Engineered in partnership with the National Geographic Institute (Institut Géographique National, IGN) in the early eighties and first tested in orbit on SPOT-2 in 1990 before being loaded aboard the Topex-Poseidon satellite in 1990, DORIS is celebrating its 20 years of service this year. Based on Doppler shift measurement, the continually upgraded system that has become an international standard-setting instrument, can also position satellites with an accuracy to the order of one centimeter. DORIS also has the capability of locating points on the ground with extreme accuracy, using the Doppler effect, and can do so in reverse, an asset for researchers working on Earth forms and movements. Celebrating its twentieth birthday aboard CryoSat-2, measuring its altitude in real-time and helping the satellite maintain its position, is a great birthday present for DORIS. For the first time, it will be the only pilot onboard!	>> Suivant Version imprimable >> Transmettre cette info par email >> Recommander ce site à un collègue / ami >> S'abonner au eTech France >> FAQ / foire aux questions >> Conditions d'utilisation >>


	Pour en savoir plus, contacts :	CryoSat - http://www.esa.int/cryosat	Code brève ADIT : 62523

	Rédacteur :	ADIT - Jean-François Desessard - email: jfd@adit.fr


	Origine :	eTech France numéro 238 (8/03/2010) - ADIT / ADIT - http://www.bulletins-electroniques.com/actualites/62523.htm

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