 Following the announcement that CryoSat @-@ 2 would be built the CRYOVEX programme was extended . Experiments were conducted in Antarctica to determine how snow could affect its readings , and to provide data for calibrating the satellite . In January 2007 the European Space Agency issued a request for proposals for further calibration and validation experiments . Further <unk> experiments were conducted on Svalbard in 2007 , followed by a final expedition to Greenland and the Devon Ice Cap in 2008 . Additional snow measurements were provided by the Arctic Arc Expedition , and the Alfred Wegener Institute 's Airborne Synthetic Aperture and Interferometric Radar Altimeter System ( <unk> ) instrument , mounted aboard a Dornier Do 228 aircraft . 
